Executive summary

In the morning hours of 26 December, 2004, huge seismic sea waves triggered by

massive undersea earthquake in the Indian Ocean caused the death of many thousands of

people, leaving tens of thousands homeless in India, Sri Lanka, Indonesia, Malaysia,

Thailand and Maldives. Fishermen, tourists and people living on the coast were

unprepared for the waves that rose upto 6 meters high throughout the Indian Ocean,

Andaman Sea and Arabian Sea. The earthquake, had its epicenter 257 km south

southwest of Banda Aceh in Sumatra, Indonesia. This was the most powerful earthquake

experienced in the region during the last 40 years.

176 persons were killed in Kerala as tsunami waves rising over the Arabian Sea

invaded the land, wreaking havoc and destruction in the coastal fishing hamlets in the

southern districts of the state.

This report presents the impact of tsunami on natural eco systems. The marine

environment in the southwest coast between Thottapally and Muttam has been

successfully affected as a result of the impact of Tsunami , as reflected by the following

findings :

The concentration of nutrients has been reduced at all transects just after tsunami.

However, values gradually picked up in the period from January to May 2005.

Primary productivity had been drastically reduced in the wake of tsunami,

especially near Vizhinjam and Kolachel. This also has improved considerably

evident from the samples collected in May 2005.

There was a lowering of plankton species diversity just after tsunami period, in

January 2005.

The fish catch has been reduced subsequent to tsunami. This has shown

considerable improvement now, as reported by the fishermen from that area.

The drop observed off Muttam indicates flow of water along the sediments to

develop certain channels in the ocean bed. The presence of factors resulting in

this channelling needs to be checked up with earlier bathymetric data.

The sediment samples collected offshore contain more coarse sand, indicating

recent transportation of the material from the coast

The presence of heavy minerals in the sediment samples collected as far as 25 km

offshore indicate that these minerals have also been transported offshore due to

high-energy backwash.

The impact of tsunami was maximum at Vizhinjam, Kolachel, and Valiyazhikkal

due to the geomorphological feature, which resemble inland basin. Impact was

least from Veli to Quilon and north of Thottappally due to long stretches of

coastal plains.

There are indicators which show that the marine environment is slowly recovering

from the impact of tsunami, as evident from the improvement in biological

productivity of this coastal stretch.

The marine ecosystem has undergone significant changes during the tsunami.

Changes in the sediment characteristics has been observed, with heavy deposition of fine

clay and silt at the 30m and 100m station all along the Kerala coast with possible changes

in the community structure, abundance and distribution of the marine benthic fauna.

Though algal blooms not has been recorded by FORV Sagar Sampada during

January 2005, extensive blooms of the cyanobacteria and trichodesmium were observed

all along the Kerala coast during March and April 2005.

Evidence of bottom disturbances by the tsunami with consequent displacement of

macrobenthic infauna have been recorded throughout the coast. In general, lighter

macrobenthic forms seem to have been transported to deeper waters by the receding

tsunami waves, whereas the heavier forms might have got settled along the shallower

waters.

As the macrobenthic fauna form an important component in the food of demersal

fishes, the observed changes of the composition and distribution pattern of macrobenthos

may have short term/long term impacts on demersal fishery of the coast.

Among the physico-chemical parameters analysed, significant changes were

observed only in surface silicate values, which were almost five times higher than normal

values. Surface nitrate values were comparatively less indicating the possibility of

increased surface primary production soon after the tsunami.

The pre-tsunami beach profiles were taken on 14th November, 2004, i.e., 42 days

before the event. Huge accretion has been taking place in the southern side of the

Kayamkulam inlet due to the predominant northerly longshore currents, during fair

weather. Erosion has taken place in the northern side due to the groin effect of the

breakwater. Thus the beach in the southern side of the inlet must have got considerably

accreted with respect to the pre-tsunami profile and thereafter till th epost tsunami beach

profiling on 15.01.2005. The field signatures on both the sides of the inlet showed

scouring and erosion.

The bathymetric survey conducted by CESS confirms the erosional tendency of

the tsunami waves. As in the case of beach, erosion is noticed in the innershelf also. The

sediment distribution pattern correlates the findings of bathometric resources. The

preliminary results indicate changes in the innershelf sediment characteristics with

shoreward migration of sandy patch off Kayamkulam.

A deterioration in the quality of groundwater was noted soon after tsunami. It

may be presumed that the pressure of the wave was transmitted underground through the

coastal aquifer ahead of the surface wave. Salinization of shallow fresh groundwater,

reduction in volume of freshwater lenses, landward shift of freshwater/saltwater mixing

zones, pollution of groundwater by chemicals and other contaminants mobilized by

flooding seawater were noticed. It is found, that after a month of the occurrence of

Tsunami, that more than 80% of the wells showed reduced values in salinity when

compared to the samples collected just after the impact of the tidal waves of Tsunami.

It was also noted that during dry summer months of 2005, salt swings back to the surface

soil again by capillary rise. The trapped salts will vertically oscillate between the perched

ground water lens and the soil horizons for many years before being completely removed.

Thus, the deleterious repercussions of sea wave intrusion are bound to last for a

long time to come, and hence necessitates monitoring of the quality of water periodically.

It may be mentioned that the entire island relies on deep ground water pumped day in and

day out to meet the fresh water needs. Groundwater is steadily being pumped out for the

last fifty years. The grave environmental impacts thereof have not been assessed.

Tsunami had a mild but definite influence on the water quality as well as the

characteristics of the sediments of the region. Surface water quality parameters

(chlorophyte and suspended solids) showed definite changes, just after tsunami and later

recovered over a period of time. This may be due to energetic mixing of coastal waters

and the freshwater flown in from the rivers. The bottom sediments have also undergone

some amount of churning leading to the release of organic mater associated with the

undisturbed bottom mud.

The effect of tsunami on the vegetation was also studied. It was noted that man-

made plantations of coconut (Cocos nucifera) intermixed with jack (Artocarpus

heterophylla), poovarasu (Thespesia populneoides) and Indian almond (Terminalia

catappa) constitute the dominant sylvan landscape of the coastal vegetation and meager

casualties of tree crops, especially coconut trees, were observed as the larger tree

populations escaped the onslaught of the killer waves.

The estuarine coastal belt and its associated natural mangrove vegetation are

highly dissected due to various anthropogenic activities. As a result, extensive mangrove

vegetations expected of the inter-tidal areas are missing and are in a highly degraded

state, having transformed into a thicket-physiognomy. Nevertheless, the mangrove

patches were found only slightly affected by the tsunami waves; a few instances of

toppled coconut trees and some uprooted shrubs were the only detectable impact. In other

words, the impact on mangroves was not specific to any individual plant species.

Elsewhere, it has been pointed out that the presence of shelterbelts and mangrove

vegetation helped in reducing the impact of coastal disasters. In addition to helping in

breaking the force of the tidal waves, these trees served as escape routes for a number of

individuals who took shelter in these trees to rescue themselves.

Satellite imageries were used for assessing the damage. There was not much

damage to the vegetation detected in IRS imageries. However, the shoreline changes

with reference to sea shallowness are remarkable. An attempt to evaluate the sea shore

changes with regard to the depth of sea, based on the soil reflectance value from the sea

bottom, indicated that because of the increase in sea depth, in future the impact of the

waves during monsoon may be of higher order in future. The water spread area has

widened after the tsunami as seen in the imagery.

Despite the massive structure, the sea walls were less effective being a structure in

continuum, without break or openings permitting water to dissipate and the tidal force to

dampen. Had the sea walls been discontinuous with occasional gaps, coupled with

shelterbelt plantations of tree crops/mangrove vegetation might have diminished the

disaster impact, as the vegetation would have served as a porous and effective barrier

than the continuous engineering structures like sea walls.

It was very evident that the populations along the beaches were directly affected

by the tsunami. The worries of the people along the coast need to be addressed and a

mitigation strategy need to be evolved. Coastal hazard zonation map need to be prepared

and a vulnerability line need to be demarcated on the coast. Massive awareness among

community need to be carried out for capacity building in the area.

Chapter I

Tsunami

1.1 Introduction The Tsunami which struck the Kerala coast on 26th December 2004 has created

wide spread havoc on human life and property. It took away many valuable life and

coastal destruction and damages to life supporting structures all along the coastal belt of

Thiruvananthapuram, Kollam, Alappuzha, Eranakulam and Thrissur. It has completely

destroyed the rhythm and livelihood and coastal population. Further, it has created

irrecoverable havoc on different elements of the environment, i.e., land, water, air and

biota. Houses have been razed to the ground, castle perished, fishing boats, nets and

fishing equipments washed away, landing center washed away, landing centers flattered

and fishing harbours sifted up and break waters and armour stones seriously damaged.

Extensive damages to water supply systems, electric installations and road

communication have resulted in disruption of life along the coastal region.

Scientific studies have been conducted by number of agencies for understanding

the impact of Tsunami in various elements of the environment and produced their own

reports. KSCSTE has decided to consolidated such study reports made by various

agencies. In this respect, KSCSTE has conducted a series of meetings and persuaded a

number of agencies for obtaining the study made by them. The primary objective was to

assess the impact of Tsunami and scientific evaluation of its influence on environment

which would enable us to combat such disasters in the future.

Tsunamis are waves generated in the ocean due to earthquake, landslides or

volcanoes. Large impulsive displacement of the ocean floor generates tsunami. The word

‘tsunami’ is Japanese and made up of two characters ‘tsu’ (meaning harbour) and ‘nami’

(meaning wave) thus meaning ‘harbour wave’.

Tsunami, which struck on 26th December 2004, was one of the greatest calamities

that the present generation has ever witnessed in terms of the loss of human life and

material damage. The dynamics of earth and science of tsunami was vividly explained,

any mechanism in timely predicting the disaster is not yet emerged out. It is understood

that earthquakes trigger tsunamis, especially, if the epicentre of which lies within the sea

or near shore area. Other natural process like volcanic eruptions, extensive landslides,

and meteoritic impact etc. can also generate gigantic waves in the sea resulting to

tsunamis.

A vertical movement along a break in earth’s crust causes most tsunamis. A

tsunami is generated when a large mass of earth on the bottom of the ocean drops or rises,

thereby displacing the columns of water directly above it (tectonic activity). Volcanoes

have generated significant tsunamis in the world. The most efficient methods of tsunami

generation by volcanoes include disruption of water by the collapse of all or part of

volcanic edifice, subsidence, an accompanying or preceding the eruption. Submarine

eruptions may also cause minor tsunamis.

Sub-aerial and submarine landslides may generate locally destructive tsunamis.

These may not be as destructive as that of a tectonic earthquake, generated tsunami.

The plate tectonics explains the dynamics of earthquakes reasonably with clarity;

plate boundaries and their alignments within the ocean bottom are clearly demarcated. It

is also possible to predict the nature of waves generated out of tsunamis and their likely

impact and extent of waves on the near shore areas through modelling studies. Large

vertical movements of the earth’s crust can occur at plate boundaries. The subduction

zones where the margin of the ocean plates slips under continental plates and deciphering

such locations are very important part of the study. In the recent incident the subduction

zone at the Indonesian plate boundary near the Java trench had generated the earthquake

waves resulting into release of total energy, which generated the killer waves. Tsunamis

are characterised by shallow water waves, with long periods and wave lengths. In the

Indian Ocean where the water depth is about 2500m, a tsunami may travels nearly 575

km/hr.

Velocity of a tsunami wave depends on the depth of water through which it

travels. Tsunami wave velocity based on depth and its wavelength is tabulated in Table 1.

Table 1. Velocity of Tsunami wave with reference to depth and wavelength.

Depth (m) Velocity (km/h) Wavelength (km)

7000 943 282

4000 713 213

2000 504 151

200 159 48

50 79 23

10 36 10.6

The height of the tsunami wave ranges from few centimetres to about 30m. Most

tsunamis are less than 3 meters in height. Tsunami waves are not noticed in deep waters.

The wave height increases when it reaches the shore. The bathymetric features and

shoreline controls the height of the wave reaching the shore.

The receeding of sea waves are usually noted prior to the tsunami. Ocean floor

may be exposed and then wave crest approaches the coast with a high speed. These

approaches the shore like flasher and causes destruction on the coast.

It is possible to predict a tsunami at various places by knowing the source

characteristics of the earthquake that generated the tsunami and the characteristics of the

sea floor along the paths of those places. The impact of tsunami was determined by the

offshore and coastal features. The reefs, bays, river estuaries, under sea features, slope of

the beach occurrence of backwater system etc. control the impact of tsunami. Though it

is difficult to predict the occurrence of earthquakes and tsunami the post tsunami studies

are helpful in predicting future tsunami impact and flooding limits at specific coastal

stretches.

1.2 Elements At Risk

All structures located within 200 m of the low lying coastal area are most

vulnerable to the direct impact of the tsunami waves as well as the impact of debris &

boulders brought by it. Settlements in adjacent areas will be vulnerable to floods & scour.

Structures constructed of wood, mud, thatch, sheets and structures without proper

anchorage to foundations are liable to be damaged by tsunami waves & flooding. Other

elements at risk are infrastructure facilities like ports & harbours, telephone and

electricity poles, cables. Ships & fishing boats/nets near the coast also add to the

destruction caused by tsunami waves.

1.3 Typical Effects

Physical damage - Local tsunami events or those less than 30 minutes from the

source cause the majority of damage. The force can raze everything in its path. It is the

flooding effect of a tsunami, however, that most greatly effects human settlements by

water damage to homes and businesses, roads, bridges and other infrastructure. Ships,

port facilities, boats/trawlers, fishing nets also get damaged.

Environmental damage - There is evidence of ever increasing impact upon the

environment on account of the effects of tsunamis. The range varies from generation of

tonnes of debris on account of structural collapse of weaker buildings, release of toxic

chemicals into the environment on account of chemical leak/spillage/process

failure/utility breakages/ collateral hazards and negative impact on the already fragile

ecosystems.

Casualties and public health: Deaths occur principally from drowning as water

inundates homes or neighbourhoods. Many people may be washed out to sea or crushed

by the giant waves. There may be some injuries from battering by debris and wounds

may become contaminated.

Water supply: sewage pipes may be damaged causing major sewage disposal

problems. Drinking water shortage arises due to breakage of water mains and

contamination. Open wells and ground water may become unfit for drinking due to

contamination of salt water and debris.

Standing Crops and food supplies: flooding by tsunami causes damage to the

standing crops and also to the food supplies in the storage facilities. The land may be

rendered infertile due to salt water incursion from the sea. All these effects are dealt in

detail in the following sections.

.

1.4 Tsunami and India

Tsunamis are frequent occurrences in certain locations bordering the Pacific

ocean, especially Japan. Tsunamis in Indian Ocean are, however rare. But the tsunami on

26th December 2004 due to a massive earthquake with a magnitude of 9.3 in Richter scale

off north Sumathra coast (3.316°N latitude and 95.854°E longitude) generated

devastating waves and affected several countries in South East Asia and in Africa. The

number of human lives lost was recorded as 186983 and missing as 42883 by United

Nations. In India it was affected in Andaman and Nicobar Island, Tamilnadu,

Pondicheerry, Andra Pradesh and Kerala. As per records of Ministry of Home affairs the

death toll in Inda is 12400 and missing is 5604. Many were injured and massive

destruction to coastal areas were recorded. Some of the Historic Tsunamis are tabulated

in Table 2.

Table 2. Tsunamis affected in India

Date Remarks

12 April, 1762 Earthquake in bay of Bengal. Tsunami wave of 1.8 m at Bangladesh

coast

19th Aug. 1868 Earthquake Mag. 7.5 in Bay of Bengal.Tsunami run-up 4.0 m at Port

Blair

31st Dec. 1881 Earthquake of mag 7.9 in the Bay of Bengal reported tsunami run-up

level of 0.76 m at Car Nicobar, 0.3 m at Nagapattinam, 1.22 m at Port

Blair

27th Aug. 1883 Karakatoa, 1.5 m Tsunami at Madras, 0.6 m at Nagapattainam, 0.2 m at

Arden

1884 Earthquake in the western part of the Bay of Bengal Tsnamis at Port

Blair, Doublet (mouth of Hoogly River)

26th June 1941 8.1 quake in the Andaman Sea at 12.90 N, 92.50

E Tsunamis on the east

coast of India with amplitudes from 0.75 to 1.25 m. Some damage from

East Coast was reported.

27th

November1945

Mekran Earthquake (Magnitude 8.1). 12 to 15 m wave height in

Ormara in Pasi (Mekran coast) Considerable damage in Mekran coast

in Gulf of Cambay of Gujarat wave heights of 11-11.5 meter was

estimated. Damage report from Gujarat coast was not available. The

estimated height of waves at Mumbai was about 2 meters, boats were

taken away from their moorings and causality occurred

26th

December2004

In India, Andaman & Nicobar Island, Tamil Nadu, Pondichery, Andhra, Kerala affected about 12400 people lose their lives & 5604 missing.

1.5 Tsunami and Kerala

There is no historic record of Tsunami in Kerala. Only Tsunami that has affected

the State of Kerala was that on 26th December 2004. The lost estimated in terms life loss

was 176 and 1600 were injured. Loss of property estimated to Cores of Rupees.

Although the entire Kerala coast experienced the effects of tsunami waves at a stretch of

10 km along the coast off Azhikkal (9°2’ N to 9°5’N) in Kollam district was the most

affected in terms of inundation, run up and erosion. Alappuzha, and Eranakulam districts

too had extensive damage due to this killer waves. The tsunami waves that hit Kerala

coast were three to five meters in height, according to the National Institute of Disaster

Management.

Plate 2. Tsunami waves in Allapad, Kollam district

It was also estimated that the tidal upsurge had affected 250 Kilometres of the

Kerala coastline and entered between one to two kilometres inland. The tsunamis

pounded 187 villages affecting 24.70 lakh persons in Kerala. As many as 6280 dwelling

units were completely destroyed and 11175 were partially damaged in the tsunami

onslaught. As many as 84773 persons were evacuated from the coastal areas in Kerala

and were accommodated in 142 relief camps after tsunami

The impacts of tsunami in various sectors are discussed in detail in the report.

Kerala coast being prone to hazards like Tsunami, Erosion, and cyclone needs a

comprehensive approach for dealing with these hazards.

1.6 Marine and Coastal Environment of Kerala

1.6.1 Introduction : The Coastal Zone in Kerala is the low land fringing the sea

extending over 560km, with a height of less than 8m from the MSL, covers about 15% of

the state’s total area of 38,863 sq.km.

A chain of water bodies, locally known as kayals running parallel/oblique to the

coastline is a characteristic feature of Kerala coast. These are mostly interconnected by

natural or man-made canals, facilitating internal navigation almost for the entire length of

the coast. Numerous perennial rivers discharge into these kayals. Southern half of the

Kerala coast harbours more of larger backwaters. The kayals of the Kerala coast are

mostly separated from the sea by elongated sandbars and based on this they can be

treated as “coastal lagoons”. The Kerala Public Works Department (cf. Water Resources

of Kerala, 1974) has identified 27 estuaries and 7 lagoons in Kerala (Table 3).

Table 3 Estuaries and lagoons in Kerala (Water resources of Kerala-PWD)

Estuaries Lagoons 1. Uppala 1. Kavvayi 2. Kumbala 2. Agalapuzha 3. Mogral 3. Enamakkal-Manakkodi 4. Chandragiri 4. Muriad 5. Kalnad 5. Kodungallur 6. Bekal 6. Sasthamkotta 7. Chittari 7. Vellayani 8. Karingote 9. Ezhimala 10. Valapattanam 11. Dharmadam 12. Tellicherry 13. Mahe 14. Kottakkal 15. Elathur 16. Kallai 17. Beypore 18. Kadalundi 19. Chettuvai 20. Ponnani 21. Vembanad 22. Kayamkulam 23. Ashtamudi 24. Paravur 25. Edava-Nadayara 26. Kadinamkulam 27. Veli

The vast low lying area fringing the coast, is not only an important physiographic

unit of the state, but also important in terms of economic activity and demographic

distribution. It constitutes 16.40 % of the area of the State, but also important in terms of

economic activity and demographic distribution . In Central Kerala most of the area

shows elevation of 4 to 6 m above MSL, whereas it is 4 to 10m north and south Kerala,

except the coastal cliffs, promontories and sloping platforms. Beach dunes, ancient

beach ridges, barrier flats, coastal alluvial plains, flood plains, river terraces, marshes and

lagoons constitute this unit. It has the maximum width in the Alappuzha and Aluva-

Kaladi regions. A characteristic feature of this unit is the existence of numerous beach

drive ridges, parallel and sub-parallel to the coast, especially in the Alappuzha-Cherthala

regions. Their orientation indicates that the strandlines belong to at least two ages, and

maximum width between the oldest and the youngest, close to the present shoreline is

18km. Further the coastal plain is seen to extend between numerous rocky ridges along

the coast (Soman, 1997).

The west flowing rivers meander in the level flats of the coastal plain, and

sometimes strike a northerly direction as they flow into the backwaters. The characteristic

formation of parallel sandy ridges along the coast, and the persistence of the system

towards the east indicate a history of repeated marine transgressions and regressions. It

has been assumed that there have been at least three significant phases of such processes

within 5000 years before present, of varied intensity and intervals. It is continuing even

now, these areas are extensively covered by coconut plantations, paddy lands, marshy

areas and a high density of human populations. Table 4 presents the wetland categories

along with their area of coverage along the Kerala coast.

Table 4 Wetland categories along the Kerala coast (Source-Space ApplicationsCentre,1992)

Category Area (sq. km) Beach and strand plain 1,378.5 Spit 0.8 Reclaimed land –1 512.9 Reclaimed land –2 24.0 Estuary 251.2 Flood plain 7.1 Islets 22.4 Lagoon 5.9 Total 2,202.8

The major renewable resources available along this coastal zone are water,

agriculture and fisheries and non-renewable resource such as placer minerals, soils,

subfossil deposits, etc. The average marine fish production from Kerala is 25% of India.

Kerala contributes around 20% of the total marine products exported from the country

which earns 1200 crores per annum while the domestic turn over from fisheries is around

12,000 crores. The unique mud banks, which appear at some locations during the

monsoon season, also contribute to the rich monsoon fishery along this coast. The

Chavara coast of Kerala is well known world over for its rich heavy mineral deposits.

The coast is well known for several places of historical importance, heritage areas

and areas of outstanding natural scenic beauty (Tables 5, 6, 7). Anjengo Fort, Bekal Fort,

and Sankumukham palace are among the important historical areas declared by the

Archaeology Dept. There are several places of outstanding natural beauty along the

Kerala coast, which probably is one of the main reasons that make Kerala an important

tourist destination. Sankumugham, Vettukad, Papanasam(Varkala), Pozhikkara-Paravur,

Neendakara and Arthungal are some of the heritage areas.

Table 5 List of historical locations along the Kerala coast (CZMP, 1995)

Sl. No. Place name District Remark 1. Kottukal Trivandrum Vizhinjam Bhagavathy temple 2. Sankumugham “ Palace, mandapam 3. Anjengo fort “ Fort 4. Thangasseri Kollam Fort & lighthouse 5. Karunagapally “ Budha image 6. Ambalapuzha Alappuzha Budha image, Karumadi

7. Vaikom Kottayam Temple with fine panels of mural paintings

8. Mattancheri Ernakulam St. Francis Church

9. Chennamangalam

Ernakulam Granite stone, Hebrew inscriptions

10. “ “ Pallipuram fort 11. “ “ Manjapra temple

12. “ Kottayil Kovilakam palace site of Raja of Villaravattath

13. “ “ Vaipikkota Seminary built by Portugese in 18th century

14. Parur “ Stone inscription

15. Chemanchery – Quilandy

Kozhikode Kappad pillar monument of the arrival of Vasco de Gama

16. Bekal Kasargod Bekal Fort

The 690km length Kerala coast faces the Arabia Sea. The coastline of Kerala is

more or less straight trending in NNW-SSE direction from north till the Thangassery

headland near Kollam. The coastline orientation south of Thangassery is in the NW-SE

direction. The offshore continental shelf bathymetry is steeper to the south. While the

100m contour is at a distance of around 40 km off Thiruvananthapuram from the shore, it

is 58km off Kasargode. The variation in the slope of the inner shelf is more pronounced.

While the inner shelf is very steep with the 50m contour distant only 11 km off

Thiruvananthapuram, it is very gentle off Kozhikode with a distance of 42 km. This

change in the bottom slope has lot of implications in the hydrodynamic and

sedimentological characteristics of the inner shelf of Kerala. Based on the bottom slopes

Kurian (1987) categorised the Kerala coast into different wave energy zones which is

found to be fully endorsed by the field data from different locations (Baba et al., 1988).

Table 6 Areas of outstanding natural beauty along the Kerala coast (CZMP, 1995)

No Place name District Remark 1. Puvar south Trivandrum Wide beach, backwater 2. Pulinkudi – Kovalam “ Rocky cliff, extensive stable beach 3. Sankumugham “ Beach, archaeological sites, palace, park 4. Veli “ Tourist Village, backwater, beach tourism, park 5. Papanasam – Varkala “ Cliff & beach, artician springs, temple 6. Edava Kollam Barrier beach & backwater at close proximity,

coconut groves 7. Kappil “ Barrier beach, extensive backwater, coastal

road 8. Pozhikkara “ Pozhi (permanently connected to sea) with

canal, temple, coconut groves 9. Mundakkal

(Jonnapuram) “ Park, extensive stable, beach

10. Thirumullavaram “ Bay, beaches, coconut groves, temple, pond 11. Palliyamturuth “ Uninhabited island (islet) with beautiful

backwater surroundings 12. Alappuzha Alappuzha Extensive stable beach, park, pier suitable for

recreational fishing 13. Fort Kochi Ernakulam Wide beach backed by backwater 14. Cherai “ Extensive beach with sea and backwater

frontage, park 15. Bekal Kasargod Fort on high cliff, wide beaches around

backwater at the vicinity 16. Kottikulam “ Promontory and pocket beaches around

Table 7 List of heritage areas along the Kerala coast (from CZMP, 1995)

Sl. No. Place name District 1. Sankumugham Thiruvananthapuram 2. Vettukad Thiruvananthapuram 3. Papanasam Thiruvananthapuram 4. Pozhikkara – Paravur Kollam 5. Neendakara Kollam 6. Arthungal Alappuzha

The hydrodynamic regime of the coastal marine zone of Kerala depicts the typical

features of a monsoon dominated tropical coast. The highest wave and current intensity

occurs during the peak monsoon months of June-July. The highest wave recorded is 9m

off Kavaratti in the Lakshadweep sea (Baba et al., 1992). The waves approaching the

coast are mostly the swells except during the peak monsoon period. The highest wave

intensity is seen during the peak monsoon months of June and July due to proximity of

the coast to the wave generating zones in the Arabian Sea. The nearshore wave intensity

decreases from south to north (Fig 3). While the maximum wave height (Hmax) recorded

is 6m at Valaithura near Trivandrum it is only 2.6m at Tellichery. Incidentally

Trivandrum coast has the highest wave intensity along the Indian (excluding islands)

coast. The longshore currents generated by the waves are generally southerly during

monsoon and northerly during the rest of the year (Baba and Kurian, 1988)

TRIVANDRUM

0

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J F M A M J J A S O N D

ALLEPPEY

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C A LIC U T

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C AL M C AL M

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TELLICHERI

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CALM

Fig. 3 Monthly mean Hs at different nearshore locations of Kerala coast in the year 1981 (after Kurian et al., 2004)

The coastal currents observed in the coastal marine zone are a resultant of wind-

driven circulation together with tidal currents, continental shelf currents and coastal-

trapped waves. Coastal currents are generally known to be southerly during monsoon and

northerly during the fair weather period. Deviations to this generally understood pattern

of coastal currents are observed and are attributed to the formation of an anticyclonic

eddy off the southwest coast during the north-east monsoon and cyclonic eddy during the

(southwest) monsoon (Shahul Hameed et al., 2004). Like the other parts of the west

coast, the coastal marine zone of the Kerala coast is also known for the occurrence of

upwelling which is strong during the monsoon. The coast is in general microtidal with the

tidal range decreasing from north to south (Table 8). While the parts of the coast north of

Kozhikode have a tidal range of around 1.5m, the tidal range is around 0.50 m in the

south along the Trivandrum coast.

Table 8 Tidal range at different tide recording stations in/near Kerala (from CZMP, 1995)

Port Lowest Low Water

Highest High Wate

Springs at Solstices

(LLWS)(m)

r

Tidal Range

(m) Springs at Solstices

(HHWS) (m)

Mangalore 0.03 1.68 1.65

Beypore 0.18 1.51 1.33

Kochi 0.20 1.05 0.85

The surficial sediments of the continental shelf and slope of Kerala can be divided

into terrigenous, biogenous and chemogenous sediments. In the shelf and slope of Kerala,

terrigenous sediments mostly occur as sands in the nearshore (up to 10 -12 m water

depth) followed by a zone of silty clays on the inner shelf. An admixture of abundant

terrigenous and biogenic constituents carpets the outer shelf. The continental slope

sediments are clayey silts with abundant carbonate tests. The surface sediment

distribution in the inner continental shelf also shows considerable diversity with respect

to the bottom slope conditions. For example, when the shallow northern parts of this

coast have fine-grained sediments dominated by silt and clay, the southern parts off

Kollam and Thiruvananthapuram have a sandy bottom (Prakash, 1991; Ramachandran,

1992; Hashimi et al., 1981).

Pleistocene sea level variations have affected shelf sedimentation and Nair (1974)

inferred that this shelf could be considered as an example of a drowned coast, formed due

to transgressive and regressive episodes. Thus, sediment facies in the shelf embodies

mixed distribution of both ancient and modern sediments presently remain inundated by

reworking processes. Nair et al. (1978) and Hashimi et al. (1978) identified three distinct

sedimentary facies, the first two facies consisting of sand and mud are of recent origin,

while the outer shelf relict carbonate sand facies are of late Pleistocene (8,000-11,000

year BP) formed at the time of marine regression. From the study of carbonate sediments

and size of quartz grains, Nair and Hashimi (1980) inferred a warmer climate and low

terrestrial run off during the Holocene. Further, feldspar content in the sediments has also

been used to infer the climatic aridity over India 11,000 years ago (Hashimi and Nair,

1986). Therefore, these evidences indicate contrast in climate between the carbonate and

clastics on the shelf suggesting rapid change from arid to humid climate.

The coastal marine zone of the Kerala is well known for the occurrence of

mudbank which is a unique phenomenon. During the southwest monsoon period when

the sea is very rough, very calm sea conditions prevail in the mud bank zones adjoining

the shorelines. Some of the locations well known for the occurrence of mud bank are

Koilandy, Njarakkal, Puthuvype, Alleppey and Purakkad. Unlike the mud banks reported

from other muddy coasts of the world (Wells and Coleman, 1981; Rine and Ginsberg,

1985), the Kerala mud banks do not show regular relief forming features. Their transient

nature, unpredictable periodicity, calmness and turbid nature of the water column are

unique. Ramachandran and Mallik (1985) reported an offshore sediment source and rapid

sedimentation in the mud bank region during the monsoon season. Baba et al. (1994),

Mathew and Baba (1995) and Mathew et al. (1995) examined in detail the wave climate

of a mud bank location, sediment characteristics during different stages of mud bank and

the wave-mud interaction processes. According to the conceptual model proposed by

them, the offshore sediments resuspended by high waves during the monsoon form a

fluid mud layer, which is transported en masse to the nearshore by the combined action of

waves and currents and cause the formation of mud bank. The duration of the mud bank

is determined by the ability of waves and currents in keeping the fluid mud without much

settling and also in overcoming its down slope movement due to gravitational force,

which controls the dissipation of mud banks.

Kerala is the most densely populated state in India with a population of 318 lakhs

in 2001. In this about 30% live in the coastal zone. The coastal population density at the

major urban centers like, Cochin, Thiruvananthapuram, Kozhikode, Alleppey and Kollam

is more than 2000 persons per sq. km. The figure is extremely high at some pockets near

the major cities like Cochin, Thiruvananthapuram and Kozhikode and at some other

places like Tellicherry, Neendakara etc.

Due to the high density of population compared to the other parts of the state the

coastal zone has undergone substantial development. Out of the total 14, 7 district

headquarters are located in the coastal zone. They are Kasaragod, Kannur, Kozhikode,

Ernakulam, Alleppey, Kollam and Thiruvananthapuram. All the four municipal

corporations, Kozhikode, Cochin, Kollam and Thiruvananthapuram and 19 municipal

towns (including the district headquarters) are situated in this zone. Easy water transport

and shipping facilities and availability of abundant water resources also attracted the

industrial and other related development projects to this zone.

Most of the industries of Kerala are situated in and around the coastal zone. In

addition to this, the bulk of the state’s wood and clay based industries, fish processing

plants, boat building yards, coir industries etc. are situated here. Most of the coastal areas

are connected by roads, railway or water transport systems. A good inland water transport

facility exists along this coast. There is substantial scope for improvement of water

transport system, which will be cheaper and more harmonious to the coastal environment.

There are three international airports in the state at Thiruvananthapuram, Kochi and

Kozhikode which are situated in the coastal zone.

A major port at Cochin, and 14 minor ports and fishing harbours are situated in

this coastal zone. Utilizing the dredged material from the shipping channel, the land area

in the vicinity of the Cochin port has been considerably enlarged; eg. Wellington island,

Candle island, Marine drive, Vallarpadam, etc. In addition to the ports mentioned above,

a series of fishing harbours and fish landing centers are established along this coast. Out

of the total length of 560km, about 260km of the coast is under varying degrees of

erosion (Sreekala et al., 1998). In order to combat this erosion, shore protection measures

are being taken along this coast for the last 100 years The shore protection structures

made along the coast are broadly classified into three: (1) seawalls, (2) seawall & groin

assembly and (3) groins. Accreted beaches are being developed into tourist destinations.

Even though the dams constructed on the rivers do not come under the coastal zone, they

have considerable influence on the sediment budget of the coastal zone. The major

schemes like Thanneermukkam bund and Thottappally spillway are constructed in the

coastal zone with a view to achieve agricultural development in the Kuttanad area. These

have created various environmental problems in this area.

In addition to the major reclamation works undertaken at the Cochin port with

dredged material, there are major governmental schemes for reclamation at Kattampally,

Kayamkulam, Paravoor, Trichur, Ponnani, Korappuzha, etc. In addition to this, private

agencies and individuals also have undertaken this activity all along the coast of Kerala.

The high density of population in this zone has necessitated a large-scale housing

development in the coastal zone. Near the urban centers the density of housing has

reached such an alarming proportion that the people of the lower strata (mainly

fisherman) even encroach the newly accreted beaches.

2.6.2 Bibliography : An account of bio-diversity of Kerala’s marine and coastal zone is

given in Chattopadhyay et al. (2003) based on a technical note prepared by M.P. Nayar

(2002). Compared to terrestrial biodiversity, the marine biodiversity and their ecological

interactions are poorly studied. Tropical marine ecosystem of Kerala coast includes

lagoons, mangrove swamps, sandy and rocky shores and open sea front. Studies on

microorganisms, phytoplankton's, zooplanktons and micro algae are done in individual

groups. The CMFRI (Central Marine Fisheries Research Institute), Kochi conducts

studies on marine biodiversity.

A close relationship between the abundance of Oil Sardines (Sardinella longiceps)

and abundance of Fragilaria Oceanica in the west coast was reported. About 291 species

of phytoplankton were listed in the Kozhikode coast. Fragilaria oceanica, Coscinodiscus

gigas, species of Chaetoceros, Rhizosolenia, Bacteriastrum, Skeletonema, Eucampia and

Asteronella were the dominat diatoms. Copepods formed the largest zooplankton

community in the Kozhikode area. The other economically important groups in Protozoa

are foraminifers and radiolarians. Flagellates form major groups with high productivity

and high turnover. Macro algae belong to the families of Cholorophyceae,

Phaeophyceae, Rhodophyceae and Cyanophyceae. Out of the total 64 families and 215

genera found in India, Kerala and Lakshadweep area have 25 families and 75 genera.

Sea grasses in the West coast are found in small shallow beds. Halophila ovalis is

associated with mangroves. Other species are Halophila beccari, Halodule pinifolia,

Enhalus acoroides and Cymodocea rotundata.

Mangrove vegetation is an important coastal ecosystem associated with tidal /

mud flats and back water systems. According to one estimate in the recent past Kerala

had 70,000 ha. of mangrove, which had diminished to less than 4200 ha (Mohanan,

1997). Some other estimate indicates the extend of mangrove vegetation to be 1671 ha at

present within a distance of 500m from the coastline.Mangroves are found in small

isolated patches along the coast and back waters. The major concentrations are found in

the Vallapattanam river mouth, Kannur district, Puthuvypene at Eranakulam district and

Kumarakom (Vembanad lake east bank) at Kottayam district. Certain patches are also

found in Kozhikode districts, Alappuzha, Kollam and Thiruvananthapuram. Table 9

provides the district wise distribution of area under mangrove vegetation in the State.

Table 9 : District – wise distribution of mangroves in Kerala (Source: Mohanan (1997)

District Area in hectares Area in % to total

area Number of major

species Kasaragod 50 1.20 15 Kannur 3500 83.35 14 Kozhikode 200 4.75 17 Malappuram 100 2.40 11 Thrissur 25 0.60 11 Ernakulam 250 5.95 17 Kottayam 20 0.45 21 Alappuzha 25 0.60 13 Kollam 15 0.35 22 Thiruvananthapuram 15 0.35 14 State total 4200 100.00 32

Important mangrove species are Rhizophora apiculata, Rhizophora mucronata,

Bruguiera gymnorrhiza, Avicenia officinalis, Sonneratia caseolaris, Sonneratia apetala,

Kandelia candal. Mangrove associates are Cerbera manghas, Hibiscus tiliaceous, Derris

trifoliata, Pandanus tectorius. These species grow behind the tidal mangrove zone. The

fern Acrostichum aureum grows in degraded habitats and Acanthus ilicifolius colonizes

saline marshes.

The strand vegetation (sand dune vegetation) comprises mainly sand binding

ipomoea pes-caprae, Spinifix littoralis, Indigofera spicata, Portulacca oleracea. The

common shrubs of the region are Calotropis gigantea, Dodonea viscosa, Scaveola

taccada, Hugonia mystax. Estuarine vegetation is classified into tidal mangroves,

prohaline and euhaline types. Prohaline type of vegetation is composed of salt tolerant

fresh water plants such as Ceratopteris siliquosa, Corchorus aestuans, Hygrophila

quadrivalvis, Salviania molesta and Sphenoclea zeylanica. Eury haline type consists of

highly salt tolerant plants like acanthus ilicifolius, Acrostichum and Pandamus

facicularis.

Kerala is endowed with a rich diversity of marine fishes with a numerical strength

ofd more than 300.They represents mainly under clupeids,perches,elasmobranhs,

leiognathids,coakers,threadfin breams,flat fishes, carangids,red mullets,etc. There are

about 54 species of prawns and shrimps commercially exploited in India. Te number of

marine mollusks exceeds 300 species with more than 10 commercially important

species.The marine echinoderm fauna comprised of around 80 species while the ancillary

resources such as sea fans,gorgonids,etc. constitute another 110 species.The state is also

enodowed with more than 25 species of sea weeds among them 12 species are

commercially very important. Macrobrachium rosenbergii,the giant freshwater prawn

is the largest prawn seen in Keralabackwaters.Apart from this there are more than 12

spcies of prawn inhabits in the estuaries and backwaters of Kerala among them M.idella

is commercially very important. Commercially important lobsters occurring in the

Kerala coast are Panulirus homarus and Panulirus polyphagus. Other species are

Scyllarus sordidus and Panulirus ornatus. Important crab species used in food are

Matuta lunaris, matuta panpipes, Scylla serrata, Neptunus sanguinolentus, Neptunus

pelagicus, Charybdis cruciata, Charybdis annulata, Charybdis edwardsi, Charybdis

natator and Varuna litterata.

Five species of marine turtles are found in Indian waters. The Hawksbill

(Eretmochelys imbricata) variety is common in tropical water. Olive Ridley

(Lepidochelys olivacea) turtle are found to nest in Kozhikode coast near Pyyoli.

Mangrove forests in India are habitats of around 177 resident and migratory birds,

of which 45 species are reported in the mangrove forests of Kerala alone. The common

species are heron, kingfisher, sea eagle, kites and storks.

India has good pelagic fishery resources comprised of mainly of oilsardine and

lesser sardines, mackerel, tuna,carangids,seer fishes, and demersal fishes such as cat

fishes, elasmobranches,sciaenids,silver bellies, besides shrimps and other crustaceans.

About 60% of marine fish yield of the country comes from the west coast, of which

Kerala contributed as high as 30%. The coastal waters in Kerala are highly productive,

the mud bank formations in the Kerala coast add to the high fish turn over.

The common hydrophytes found in the wetlands of Kerala are classified as

submerged and emerged types and they are further classified as free-swimming

(phytoplanktons) and floating types. Some one of the common wetland flowering plants

are Eichornia crassipes, Pistia stratiotes, Monochoria vaginalis, Monochoria hastata,

Limnocharis flava, Lagenandra meeboldii, L.toxicaria, Colocasia esculenta, Nelumbo

nucifera, Nymphaea nouchali, Blyxa aubertii, Blyxa octandra, Hydrilla verticillata,

Hygrophila auriculata, Xyris indica, Limnophylla chinensis, Limnophylla indica,

Pandanus furcatus, Pandanus fascicularis and Pandanus thwaitesii.

Important medicinal plants available in the coastal belt which help in local

traditional medical practices are Vaymabu (Acorus calamus), Adalodakam (Adhatoda

vasica), Aloe vera, Perumaram (Ailanthus triphysa), Koovalam (Aegle marmelos,

Kiriath) (Andrographis paniculate), Aristolochia tagala, Sathavaari (Asparagus

racemosus), Bramhi (Bacopa monnieri), Thazhuthama (Boerhavia diffusa), Mukkuti

(Biophytum sensitivum), Bramhi (Bacopa monnieri), Kanikonna (Cassia fistula), Uzhinja

(Cardiospermum halicacabum), Kodangal (Centella asiatica), Vayana (cinnamomum

verum), Cheruthekku (Clerodendron serratum), Veluthashangupuspam (Clitoria ternatea),

Nilapana (Curcrligo orchioides), Karuka (Cyperus dactylon), Mulapalkodi (Euphorbia

hirta), Kaiyonni (Eclipta prostrata), Chakkarkolli (Gymnema sylvestre) Adumbuvalli

(Ipomoea per-caprae), Neerkanthalam (Lagenandra ovata), Kizhanelli (Phyllanthus

amarus), Kalluruki (Scoparia dulcis), Krunthotti (Sida cordifolia), Amrutu (Tinospora

cordifolia), Nerinjil (Tribulus terrestris) Vallipala (Tylophora indica ) and Murikkotti

(Zornia diphylla).

Chapter II Ecological Impact Of Tsunami On The Nearshore Western Coasts Of Kerala And Tamil Nadu

Dr.C.S.P. Iyer C-MARS, RRL

2.1 Introduction

India has a long coastline (~7500 km) and a large Exclusive Economic Zone (EEZ) (~2

million sq. km.) that includes two major groups of islands, all of which are susceptible to

different coastal hazards. Peninsular India comprises of nine populous states, with a significant

component of their economy in some way related to the sea. This includes fishing, shipping,

ports and harbours, tourism and allied industries. The tsunami that hit India, along with some of

the other South Asian countries on 26 December 2004 served as a rude reminder that our coastal

areas are highly vulnerable to natural hazards. Nearly 25% of the Indian population lives in the

coastal zone. The death toll is estimated to be 12,400, led to an immediate response to what the

tsunami had reminded us of our vulnerability to coastal hazards. It was felt that we needed to

take holistic look at possible sources of coastal hazards and adopt a concerted approach towards

our preparedness for these.

The impact was severe on the S.E. coast and comparatively moderate on the S.W. coast.

The Department of Ocean Development (DOD) Research Vessel, MV Sagar Purvi, managed by

the National Institute of Ocean Technology (NIOT) was utilized to assess scientifically the

impact on the coastal marine environment. Sagar Purvi has an over all length of 30m and breadth

of 6m. It has a draft of 1.9m only so that it can cover the coastal oceans. It has all the facilities

such as wet and dry laboratories for sample analysis and preservation. The lab has Auto

Analysers, Spectrophotometer, Spectrofluorometer, clean work benches, water purification

plants, zoom stereomicroscopes, incubators etc. for onboard analysis of samples collected and

computers interfacing with the equipments. The vessel has Global Positioning System (GPS),

Gyrocompass, Magnetic compass, Radar, Navigation Echo sounder, etc.

The first Cruise was undertaken just after the tsunami from 7th to 17th of January 2005,

which covered the coast from Muttam in the south to Thottappally in the north. A second set of

measurements was undertaken in April to specifically cover Vizhinjam transect. This was

followed by a recent Cruise during May 13 to 22.

The major scientific questions, which had to be answered, are the following

1. Are there any major changes in the marine environment as an aftermath of the Killer

waves?

2. If there are any major changes, has the sea the potential to rejuvenate itself in course of

time?

3. How is it that certain coastal areas have been spared, where as some adjacent areas have

been affected drastically?

The answers to these questions can come only by an intense monitoring of the coastal

regions (coastal lands and seas), temporally as well spatially.

2.2 Choice of transects/stations, sampling and analysis

Along the southwest coast, seven transects were selected, extending for a distance of

25kms off the coast (Fig. 1). This transects were selected based on the intensity of impact of

tsunami. The transects chosen were Thottapally, Valiyazhikkal, Vizhinjam, Kolachel, and

Muttam. At each transect, stations were chosen at 5 km intervals, up to a distance of 25 km from

shoreline. The study was carried out from 7th to 17th of January 2005, using the Research Vessel

“Sagar Purvi”.

2.3 Sampling programme

At each stations, online measurements were taken for the parameters–conductivity,

temperature, depth, and chlorophyll a, at 1 metre interval, from surface to bottom. Samples of

water were collected from surface, mid depth, and bottom, using the Hydro Bios water sampler.

Sediment samples were collected using a Van Veen grab sampler. Water samples were analysed

for dissolved oxygen and nutrients by Standard Methods.

Sediment samples collected were taken up for analysis. Size analyses were carried out by

the standard sieve technique. About 100gm of sample for mixed sediments is taken up for studies

after careful removal of large shells and shell fragments by hand picking. The samples are treated

with 100 ml of H2O2 (6%) to remove organic matter and thoroughly washed with distilled water

after 48 hours to remove salts, and decanted thoroughly with sufficient water till all silt and clay

is removed. Sub-samples were taken after coning and quartering and spread over a girded tray.

Both sand and silt + clay are weighed separately and the former is subjected to sieving using

meshes of 1/2 phi interval and the weight percentages are computed. Graphic measures: mean

size, standard deviation, skewness, and kurtosis were also computed for each set of textural data

on Grain Size version 1.0.

Separate water samples were taken for Phytoplankton studies. For zooplanktons, oblique

hauls for a fixed time period were made using a Heron Transfer Net with attached flow meter.

The samples of planktons, thus collected, were analysed for the composition and population

counts. Primary productivity measurements were carried out using the carbon 14 method.

Microbiological studies on samples of water were carried out by the plating technique with

different culture media.

The depths of the stations were assessed using the echo sounder, available on board the ship and

the profiles scanned for any abnormalities in the ocean floor.

Fig. 1. Selected transects and stations

2.4 Results

The measured parameters are plotted as contour maps for effective presentation of the

data. The contour maps for water temperature, salinity, pH, dissolved oxygen for the immediate

post tsunami period (Jan-2005) are shown in figures 2-5 and that for NO2–, NO3

–, PO43–, SiO4

3–

Jan 2005 and May 2005 are shown in figures 6-11. Isolines are prepared for biological

measurements for the pre tsunami, immediate post tsunami (Jan-05), and May 2005 periods (fig.

12-20). Sediment texture and mineralogical analyses were carried out in order to determine any

possible back wash along the ocean bottom. The variation in their texture is represented in the

fig. 21.

2.5 Discussions

In order to assess the impact of tsunami; we have to compare the present data with that of

pre tsunami.

2.5.1 Thottapally

For comparison, we do not have any earlier data on the Thottapally transect. However,

data is available for Allapuzha, 10 km north of Thottapally. Therefore, as an approximation, a

comparison has been made of the present data at Thottapally at 5 km offshore, with that reported

for Allapuzha at the same distance from shore. As can be seen, among the physico-chemical

parameters, there is a steep decrease in the concentrations of phosphate, and to a certain extent in

that of nitrate, nitrite, and silicate in the immediate post tsunami scenario. The more glaring

difference is in biological parameters. At all the stations in the Thottapally transect, primary

productivity, chlorophyll a, phytoplankton cell counts, zooplankton biomass, and zooplankton

population have decreased just after Tsunami. However, the results of on the samples collected

in May 2005 shows that the primary productivity as increased, as also those of chlorophyll. The

population of zooplankton is also increased. The microbial population had decreased just after

tsunami.

2.5.2 Valiyazhikkal

Looking at the chemical parameters of the water column, it is seen that the phosphate

concentration has appreciably decreased compared to the earlier data just after tsunami.

Regarding the other nutrients, a slight decrease in the concentrations of nitrite and silicate has

been noticed (Table 2). However the analysis of phosphate in the recent sample indicates that

there is a regeneration of phosphate. The biological parameters of primary productivity,

chlorophyll a, phytoplankton, zooplankton counts and biomass have come down just after

tsunami (Table 5). However, the subsequent samples collected in May 2005 indicate that the

primary productivity has improved. Just after tsunami the microbial population had shown

depletion.

2.5.3 Vizhinjam

All the nutrients have shown considerable decrease in concentrations in the samples taken

just after tsunami, compared to the earlier data taken before tsunami (Table 3). This is also

reflected in the biological parameters of primary productivity, chlorophyll a, phytoplankton and

zooplankton cell counts, and zooplankton biomass (Table 4). This is also reflection of the

decrease in biological productivity is also seen in the composition of the phytoplankton species.

The present set of samples indicates that there is an improvement in the biological parameters,

which is finally reflected in the improved primary productivity of the area. The pre tsunami data

identifies 15 species, where as the present data indicated only six species. As in the case of the

other two transects discussed above there is a decrease in the population of the different types of

bacteria, just after tsunami.

2.5.4 Kolachel and Muttam

These transects have not been included under the COMAPS programme and as such there

is no earlier data available. Therefore no comparisons could be made. Clarity of water was not

so high during the immediate post tsunami period compared to the coastal waters off Vizhinjam.

In general, the concentrations of nutrients, especially phosphate and nitrite are in the same range

as those of Thottapally, Valiyazhikkal, and Vizhinjam. However, there is more of Phytoplankton

population and naturally more of primary productivity and that of fish population. The improved

biological productivity is also reflected in the present set of samples collected in May 2005.

2.6 Sediment distribution

The majority of samples collected in the area under discussion is fine sediments made of

silt and clay except a few samples, which are mixed with sand and gravelly sand. The mixed

sediment samples are mainly recovered from the area off Vizhinjam and Muttam. The sediments

off Vizhinjam and Muttam can be texturally grouped into two sand and gravelly sand. Sand is

generally medium to coarse at Muttam and fine to medium off Vizhinjam. In general the seabed

in the northern part, off Karunagappally and Thottapally is predominantly covered by clay and in

the southern part by sand. The sand comprises shell fragments and coarse detritals like quartz,

feldspar, pyroxene, etc. Heavy minerals are also found in minor amounts.

2.7 Ocean bathymetry

Bathymetric studies just after tsunami showed a sudden drop in the sea bed of the order

5m. off Muttam at latitudes of 8.03o. This has been confirmed from the data using the echo

sounder during subsequent cruise of May 2005 (Fig. 21).

2.8 Conclusions

The post Tsunami results indicate that the marine environment in the southwest coast between

Thottapally and Muttam has been affected as a result of the impact of Tsunami. This is reflected

by the following assessments.

1) The concentrations of nutrients had come down at all transects just after tsunami.

However, these picked up in the period from January to May 2005

2) Primary productivity had drastically reduced in the wake of tsunami, especially at

Vizhinjam and Kolachel. This also has improved as evident from the samples collected

in May 2005

3) There was a lowering of plankton species diversity just after tsunami period, in January

2005

4) The fish catch was affected subsequent to tsunami. This shows improvement now, as

reported by the fishermen

5) There was a sudden drop in microbial population, following tsunami

6) The drop observed off Muttam indicates flow of water along with sediments to develop

certain channels in the ocean bed. The presence of factors conducive to this channeling

should be checked up with earlier bathymetric data

7) The sediment samples collected offshore, have more of coarse sands, indicating their

recent transportation from the coast

8) The presence of heavy minerals in the sediment samples collected as far as 25 km

offshore indicate that along with coarse sands these have also been transported due to

high-energy backwash

9) The impact of Tsunami was maximum at Vizhinjam, Kolachel, and Valiyazhikkal due to

the geomorphic feature resembling inland basin. Impact was least from Veli to Kollam

and north of Thottappally due to long stretches of coastal plains

10) It is heartening to note that the marine environment is slowly recovering from the impact

of tsunami. This is evident from the improvement in biological productivity of this

coastal stretch

Fig. 2. Isolines of Temperature (oC)– Jan 2005

Fig. 3. Isolines of Salinity– Jan. 2005

Fig. 4. Isolines of pH– Jan. 2005

Fig. 5. Isolines of Dissolved Oxygen– Jan. 2005

Fig. 6. Nitrate (µmol/L) – Jan. 2005

Fig. 7. Nitrate (µmol/L)– May 2005

Fig. 8. Nitrite (µmol/L)- Jan 2005

Fig. 9. Nitrite (µmol/L)- May 2005

Fig. 10. Phosphate (µmol/L)- Jan 2005

Fig. 11. Phosphate (µmol/L)- May 2005

Fig. 12. Primary productivity (Nos/m3)– Pre tsunami

Fig. 13. Primary productivity (Nos/m3)– Post tsunami (Jan-05)

Fig. 14. Primary productivity (Nos/m3)– May 2005

Fig. 15. Chlorophyll a (mg/m3)- Pre tsunami

Fig. 16. Chlorophyll a (mg/m3)- Jan.2005

Fig. 17. Chlorophyll a (mg/m3)- May 2005

Fig. 18. Zooplankton biomass (ml/m3)- Pre tsunami

Fig. 19. Zooplankton biomass (ml/m3)- Jan 2005

Fig. 20. Zooplankton biomass (ml/m3)

Fig. 21. Latitudinal Depth profile along Muttam to Kolachel transect, note the channelised flow at 8.03

latitude

Table. 1. Comparison of Chemical parameters at Vizhinjam

Parameters Pre tsunami Post tsunami

Jan-05

Water temperature 28.26 28.26

Salinity 33.82 33.24

PH 8.16 8.30

DO 4.69 3.16

NO2– 1.69 0.04

NO3– 4.25 1.29

SiO43– 2.52 1.30

PO43– 1.86 0.19

Table. 2. Comparison of Chemical parameters at Valiyazhikkal

Parameters Pre tsunami Post tsunami Jan-05

Water temperature 28.26 28.16

Salinity 33.62 33.21

pH 8.21 8.29

DO 4.84 5.61

NO2– 0.18 0.04

NO3– 3.25 3.16

SiO43– 2.34 1.70

PO43– 1.58 0.18

Table. 3. Comparison of Biological parameters at Muttam

Parameters Post tsunami Jan-05 May 2005

Primary productivity

(Mg/Cm/d) 18.62 160

Chlorophyll a mg/m3 0.12 0.77

Phytoplankton (Nos/L) 265

Zooplankton Biomass

(ml/m3) 0.05

Zooplankton population

(No/m3) 76 212

Table. 4. Comparison of Biological parameters at Vizhinjam

Parameters Pre tsunami Post tsunami Jan-05 May 2005

Primary productivity

(Mg/Cm/d) 145.6 10.15 122

Chlorophyll a mg/m3 1.4 0.07 0.63

Phytoplankton (Nos/L) 2460 65

Zooplankton Biomass

(ml/m3) 0.14 0.03

Zooplankton population

(No/m3) 248 52 126

Table. 5. Comparison of Biological parameters at Valiyazhikkal

Parameters Pre tsunami Post tsunami Jan-05 May 2005

Primary productivity

(Mg/Cm/d) 186.32 96.58 245

Chlorophyll a mg/m3 1.19 0.43 1.13

Phytoplankton (Nos/L) 3862 1955

Zooplankton Biomass

(ml/m3) 0.11 0.12

Zooplankton population

(No/m3) 168 143 163

Chapter III

IMPACT OF TSUNAMI ON THE MARINE ECOSYSTEM AND ITS RESOURCES

A CASE STUDY OF THE KERALA COAST Centre for Marine Living Resources and Ecology

Department of Ocean Development Church Landing Road

Kochi-16

3.1 Background

The Centre for Marine Living Resources & Ecology (CMLRE), Department of

Ocean Development, Kochi is engaged in the collection, analysis and interpretation of

data pertaining to the living resources and their physical environment with a view to

develop an ecosystem approach to the management of the Marine Living Resources

(MLR) of the Indian EEZ. The state of art research vessel FORV Sagar Sampada, (Fig–1)

is exclusively utilized for these studies, from the IXth Plan period onwards.

Fig-1: FORV Sagar Sampada

Following the 26th December 2004 tsunami which hit the Indian coasts, the Group

carried out 2 dedicated cruises of FORV Sagar Sampada to assess the impact of the

tsunami on the Marine Ecosystem and its living resources.

3.2 Materials and Methods

The first of these cruises (FORV- 230) was carried out along the Kerala, Tamil

Nadu and Andhra Pradesh coasts from 5.1.2005 to 19.1.2005. Scientists from Cochin

University, National Institute of Oceanography, CAS in Annamalai University and

CMLRE participated in the cruise under the leadership of Prof. Dr. R. Damodaran of

CUSAT. This report is prepared by CMLRE based on the analysis and interpretation of

data and samples collected through FORV cruise No. 230.

Data and samples were collected from 30, 50, 100 and 200 m depths along 6 pre

determined transects off the west coast viz Kozhikode, Vadanapally, Kochi, Kollam,

Thiruvananthapuram and Cape Comorin [Kanyakumari] (fig-2). This was essentially a

revisit to the stations along the said transects, which were covered extensively during the

IXth plan period.

73 74 75 76 77 78 79 80 81 82 83 845

6

7

8

9

10

11

12

13

14

15

Kozhikode

Vadanapally

Kochi

kollamTrivandrum

Cape

Nagapattnam

Cudallore

Madras

Krishnapattnam

Fig-2: FORV-230; Cruise track showing sampling stations.

At each station vertical profiles of temperature, salinity and DO were taken using

CTD (General oceanics;SBE 911). Salinity from CTD were checked and calibrated with

autosal values.

DO values were checked and calibrated by Winkler method . Water samples were

further analyzed for macronutrients (Nitrate, Nitrite, Phosphate and Silicate) using 6

channel Skalar autoanalyser following standard procedures. Zooplankton collections

were made using Bongo net (surface collection) and Multiple Plankton Sampler (vertical

sampling). Sediment samples were collected from 30, 50, 100 and 200 m depths along

each transect using Smith-McIntyre grab of 0.2 Sq.m surface area. Sediment samples

were utilized for studies on the benthos, grain size characteristics and organic matter

content. Grain size analysis was carried out using particle size analyser. Results obtained

were compared with the pre-tsunami data of FORV Sagar Sampada obtained from FORV

Data centre.

3.3 Results and Discussions:

3.3.1 Bottom topography and sediment characteristics: Bottom topographic features

of the Kerala coast is shown in fig-3.

Fig-3: Bottom topography and depth contours of Kerala coast.

The impact of tsunami was severe along the Kollam-Kochi coast, were the 2000

m depth contour line is relatively close to the coast. It may be possible that the steep

gradient of the sea floor along the area might have influenced the wave parameters viz,

wave height, wave refraction and wave breaking thereby amplifying the extend of

damage due to tsunami.

3.3.2 Sediment Characteristics :The Kerala coast has mostly sandy bottom up to the

200 m depths except at 30 m off Calicut (clay-silt), 100 m off Kochi (sand-silt-clay) and

30m off Kollam (silt-clay-sand) (fig-3). Analysed results on the sediment characteristics

along the 30m and 100m depths before and after the tsunami is represented in fig-4 and

fig-5. For example in Fig-4 & 5, Cape stands for Kanyakumari pre-tsunami values and

Cape-2 for post-tsunami values. At the 30M stations of this transect, only pre-tsunami

values are indicated as data on post-tsunami could not be collected due to failure of grab.

Similarly other transects shown in the figure viz klm klm2, tvm tvm2, kch kch2, kzh kzh2

and vad vad2 corresponds to the pre and post tsunami values off Kollam,

Thiruvananthapuram, Kochi, Calicut and Vadanapally.

cape klm klm2 tvm tvm2 kch kch2 kzh kzh2 vad vad20

20

40

60

80

100

Wei

ght %

Stations West coast 30m depth

sand silt clay

Fig-4 Stations West Coast 30m depth

The 30m stations along the transects show increase in percentage content of lay

and silt in the sediment after the tsunami. Maximum deposition of clay was at the 30m

stations off Calicut (Kzh-2) where it was 62.0%, followed by Kollam (klm-2) where the

clay content was 39.6%. Corresponding increase in the organic matter content was

noticed at the 30m stations off Calicut (9.8%) and Kollam (3.6%). Along the 100m depth

profile also there was marginal increase in clay and silt. In the post-tsunami sediment

samples from 100m depth, percentage content of clay was maximum at Kochi (21.5%)

followed by Kollam (12.5%), whereas it decreased to 1.2% off Calicut. Silt deposition

was maximum (20.1%) at 100m depth off Calicut . A comparison made along the Calicut

transect gave the following details. At 30M depth off Calicut, the pre tsunami (khz)

sediment characteristics were 13.6% sand, 45.0% silt and 41.4% clay whereas the post

cape cape2 tvm klm klm2 kch kch2 kzh kzh20

20

40

60

80

100

sand silt clay

Stations West coast 100m depth

Wei

ght %

Fig-5 Stations West Coast 100m depth

tsunami (khz-2) sediment characteristics are nil sand, 37.9% silt and 62.0% clay.

Significant deposition of fine clay was observed at this station after the tsunami. At the

100m depth along the same transect, the pre-tsunami levels of sand, silt and clay were

87.2%, 9.1% and 3.7% respectively. The post-tsunami levels at the 100m depth station

off Calicut (khz-2) are 78.7% sand, 20.1% silt and 1.1% clay.

The above results suggest the possibility of disturbances of the sea floor due to the

tsunami effect. Comparison of the pre and post tsunami sediment characteristics at 30m

and 100m depth zones of the Kerala coast indicates significant deposition of clay and silt,

following the tsunami. The observed variations in the sediment characteristics are not the

result of bottom trawling operations has been ascertained by comparing the pre-tsunami

values of FORV cruise 162 [Feb 1998] with our recent records (July 2004) of the

sediment characteristics for Calicut (Beypore), Ponnani [Vadanapalli], Kochi, Kollam

and Trivandrum (vizhinjam). Since the values given in Table-1 are more or less

consistent with the pre-tsunami values taken for comparison, the possibility that the

observed disturbances may be due to bottom trawling operations is ruled out. The

observed variations in sediment characteristics may have long-term impacts on the

composition and abundance of the benthic fauna. Detailed investigations need to be

carried out to monitor long-term effects and its possible impacts on the demersal fishery.

Table-1: Sediment characteristics recorded in July 2004.

Station Depth Sand% Silt% Clay% Beypore 20

5075

100150

0.587.185.383.491.9

41.24.76.7

14.44.0

58.3 8.2 7.9 2.2 4.0

Ponnani (Vadanapalli)

205075

1.270.875.3

38.427.715.9

60.4 1.5 8.7

Kochi 205075

100150

94.278.877.176.695.1

0.813.319.119.01.9

4.9 7.9 3.8 4.3 3.0

Kollam 2050

15.297.3

64.50.9

20.2 1.8

75100

86.590.3

11.26.3

2.3 3.7

Vizhinjam 205075

100150

93.995.590.757.896.6

1.42.15.1

16.71.1

4.7 2.3 4.2

25.4 2.3

3.3.3 Physical and Chemical Oceanographic features: Pre and post tsunami values

in Sea Surface Temperature (SST), Sea Surface Salinity (SSS), depth of mixed layer

(MLD) and nutrients such as nitrate (NO3), Phosphate (PO4) and Silicate (SiO4) are

compared. The SST for Jan 2005 (28.3° to 28.6° C) were compared with the Jan 2003

SST for the area (Fig-6).

Distribution of SST(Deg C)- pre tsunami Distribution of SST(°C) Pre-tsunamiSea Surface Temperature (°C) -Post Tsunami

Distribution of SST(°C) Post-tsunami

75 75.5 76 76.5 77

8

9

10

11

75 76 775 .5 6.5 778

8.5

9

9.5

10

10.5

11

Fig-6 Isolines representing SST

Comparatively higher values of SST was observed all along the coast after

the tsunami. This may be due to the shoaling of offshore surface waters to the

coast under the influence of the tsunami waves. However, the observed values are

within the range of the interannual fluctuations in the winter monsoon of the area.

Near normal SSS Values are recorded for January 2003(pre-tsunami) and January

2005(post-tsunami) (Fig-7).

Distribution of SSS(PSU)-Pre TsunamiDistribution of SSS(psu) Pre-tsunami Sea Surface Salinity (psu)-Post TsunamiDistribution of SSS(psu) post-tsunami

75 75.5 76 76.5 778

8.5

9

9.5

10

10.5

11

11.5

12

75 75.5 76 76.5 77

8

9

10

11

Fig-7Isolines for Sea Surface Salinity.

Post tsunami Mixed Layer Depth (MLD) values were compared with the

pre tsunami MLD values for January 1998 (fig-8). The MLD patterns for the two

years are nearly similar which indicates that variations, if any, in MLD due to

tsunami might have been only a temporary phenomenon and that normal MLD

conditions could have been restored by the time the post-tsunami measurements

were taken.

75.75 5 76 76.5 77

8

9

10

11

Distribution of MLD (m)-Pre tsunamiFig-8:

75 75.5 76 76.5 77

8

9

10

11

Distribution of MLD (m)-Post TsunamiFig-8:

The surface concentration of major nutrients viz nitrate, phosphate and

silicate after the tsunami were compared with January values of nutrients for

previous years. Post tsunami surface nitrate levels south of Kochi (fig-10) were

much less (0.05-0.40µ mol/L) compared to January 2003 data (0.80-1.1µ mol/L),

whereas north of Kochi such a sharp decrease in nitrate level is not observed.

Fig 8 – Distribution of MLD

Surf (SurfaceDistribution of NO3 micromole)/L Jan 2003 ace distribution of Nitrate Micromole)- January 2003 Surface d

SurfaceDistribution of NO3 micromole/L Jan 2005 istribution of NO3 (Micro mole)-January 2005

75 75.2 75.4 75.6 75.8 76 76.2 76.4 76.6 76.8 77

8

8.5

9

9.5

10

10.5

11

75 75.5 76 76.5 777

7.5

8

8.5

9

9.5

10

10.5

11

Fig-9: Distribution of surface nitrate

On the other hand, sea surface phosphate values south of Kochi, show an

increase (0.20-0.40µ mol/L) after the tsunami, compared to the pre-tsunami

values of 0.16-0.175 µ mol/L recorded during January 2005(fig-10). North of

Kochi such variations in surface phosphate values has not been observed.

75 75.2 75.4 75.6 75.8 76 76.2 76.4 76.6 76.8 778

8.5

9

9.5

10

10.5

11

S

Surface Distribution of PO4 micromole/L Jan 2003 urface distribution of PO4 (Micro mole)-January 2003

75 75.5 76 76.5 77

7.5

8

8.5

9

9.5

10

10.5

11

Surface distribution of Posphate (Micromole)-January 2005Surface Distribution of PO4 micromole/L Jan 2005

75 75.2 75.4 75.6 75.8 76 76.2 76.4 76.6 76.8 778

8.5

9

9.5

10

10.5

11

Surface distribution of Silicate (Micromole) - january 2003SurfaceDistribution of SiO4 micromole/L Jan 2003

75 75.5 76 76.5 77

7.5

8

8.5

9

9.5

10

10.5

11

Fig-11: Distribution of surface silicate

Surface distribution of SiO4- January 200SurfaceDistribution of SiO4 micromole/L Jan 2005 5

Fig-10: Distribution of surface phosphate

All along the Kerala coast, post-tsunami surface silicate values were very high,

almost five times the pre-tsunami values recorded in Jan 2003.

Though no algal blooms were observed along the Kerala coast during January

2005, extensive blooms of the Cyanobacteria, Trichodesmium were recorded all along the

coast by FORV Sagar Sampada during the months of March and April 2005. As blue-

green algae [Trichodesmium] is known to have capability to fix atmospheric nitrogen, it

will be worth exploring the possibility of such blooms as a stabilizing mechanism for sea

surface nitrate depletions. The observed variations in the physical and chemical

parameters are only short term deviations and may not necessarily have any medium term

or long term impact on the ecosystem or its biotic components.

3.3.4 Biological oceanographic features :

Marine Benthos: Results presented here are based on the analysis of numerical

abundance and biomass of the macro benthic infauna from the 30m and 100m sediment

samples.

The numerical abundance of macrobenthic infauna from the 30m depth stations

off Kerala coast is represented in fig-12. As could be seen, the macrobenthic infauna at

the 30m depth profile of the Kerala coast is dominated by polychates, crustaceans and

molluscs. Numerical abundance of macrobenthos show significant drop at Calicut,

Vadanapalli, Thiruvananthapuram and Cape Comorin, whereas the number show

marginal increase at Kochi and Kollam.

0

1000

2000

3000

4000

5000

6000

7000

kzh kzh2 vad vad2 kch kch2 klm klm2 tvm tvm2 cape cape2

st at i ons

N umerical ab und ance o f M acro b ent ho s- 3 0 m d ept hSo ut h west co ast

Others

Molluscs

Crustaceans

Polychaetes

Fig-12

The numerical abundance of macrodenthos at each station after the tsunami (khz-

2, vad-2, kch-2, klm-2, tvm-2 and cape-2) are compared with the pre tsunami data of

FORV cruise 162 [Feb 1998] for the same season. Along the 100m depth contour of the

Kerala coast, our analysis show an increase in the numerical abundance of macro benthic

infauna at all the stations except at Cape Comorin (Fig-13).

0

500

1000

1500

2000

2500

3000

3500

kzh kzh2 vad vad2 kch kch2 klm klm2 cape cape2

st at i ons

N umerical abundance o f M acrob ent ho s10 0 m S.W coast

Ot hers

Molluscs

Crust aceans

Polychaet es

Fig-13

Group wise biomass of macrobenthic infauna along the 30m and 100m depth

contours are represented in Figs 15 & 16. Off Calicut, there is no noticeable increase in

the biomass at the 30m station, whereas significant increase in the biomass is seen for the

100m station. The 30m station off Vadanapally show significant increase in the biomass,

whereas at the 100m station, there is a significant decrease. Along the Kochi transect, the

30m station show a sharp fall in biomass whereas the fall is only marginal at the 100m

station. Along the Kollam transect, there is a significant increase in the biomass both at

the 30 and 100m stations. For the Thiruvanthapuram transect, data is available only for

the 30m station, which show sharp decrease in biomass of the macrobenthos. At Cape

Comorin (Kanyakumari), there is significant decrease in the benthic biomass both at the

30 and 100m depths.

0

5

10

15

20

25

30

35

kzh1 kzh2 vad1 vad2 kch1 kch2 klm1 klm2 t vm1 t vm2 cape1 cape2

St at io ns

Groupwise biomass- macrobenthos- west coast (30m depth)Others

Molluscs

Crustaceans

Polychaete

Fig-14

0123456789

10

Bio

mas

s in

g /

sq.m

kzh1 kzh2 vad1 vad2 kch1 kch2 klm1 klm2 cape1 cape2

Stations

Groupwise biomass of macrofana-100m depth - SW coastOthers

Molluscs

Crustaceans

Polychaete

Fig-15

From the available data, it can be inferred that the tsunami might have caused

disturbances of the sea bottom, displacing the benthic community. Sharp decrease in the

numerical abundance along the 30m depth profile, may be due to the possibility of mass

transport of the young and lighter benthic fauna which have comparatively less developed

anchoring mechanism. Increase in the benthic biomass along the 30m may be due to the

settlement of heavier macrobenthos brought back by the receding waves. At the 100m

depth range also, increase in numerical abundance of macrobenthos is consistent at most

of the stations, from which it is to be inferred that the lighter forms would have settled

in the deeper waters, which also explains the observed variations in the biomass.

However, a clear picture can emerge only after the full analysis of sediment samples from

the remaining 50 and 200m depth stations.

The observed variations in the numerical abundance and biomass of the

macrobenthic infauna may not be due to bottom trawling operations, as the observed

values shows both significant increase and decrease in biomass and numerical abundance

along the different stations. These are not consistent with the disturbances to be expected

from bottom trawl operations . Further, as most of the macrobenthic infauna have an

average life-span of only one year, changes if any, are expected to be gradual and not

abrupt as observed after the tsunami. Also, the displacement of macrobenthic fauna from

their natural habitats to alien grounds can lead to stress and consequent mortality leading

to depletion of the standing stock of the benthos. It is well established that the demersal

fishes are dependent on the macrobenthos for their food and that the pelagic larvae of the

benthic forms contribute substantially to the zooplankton biomass. The short term/long

term impacts of such changes to fishery should be examined in detail.

3.4 Conclusions:

(i) Significant changes in the sediment characteristics has been observed after the

tsunami, with heavy deposition of fine clay and silt at the 30m and 100m station

all along the Kerala coast with possible changes in the community structure,

abundance and distribution of the marine benthic fauna.

(ii) Among the physico-chemical parameters analysed , significant changes were

observed only in surface silicate values, which were almost five times higher than

normal values. Surface nitrate values were comparatively less indicating to the

possibility of increased surface primary production soon after the tsunami.

(iii) Though algal blooms were not recorded by FORV Sagar Sampada during January

2005, extensive blooms of the Cyanobacteria, Trichodesmium were observed all

along the Kerala coast during March and April 2005. Since blue green algae are

known to have the ability to fix atmospheric nitrogen, the possibility of such

blooms as a stabilizing mechanism for sea surface nitrate depletions need to be

explored.

(iv) Evidences of bottom disturbances by the tsunami with consequent displacement

of macrobenthic infauna have been recorded through out the coast. In general

lighter macrobenthic forms seem to have been transported to deeper waters by the

receding tsunami waves, whereas the heavier forms might have got settled along

the shallower waters.

(v) As the macrobenthic fauna form an important component in the food of demersal

fishes, the observed changes of the composition and distribution pattern of

macrobenthos may have short term/long term impacts on demersal fishery of the

coast.

Chapter IV

IMPACT OF TSUNAMI ON MARINE FISHERIES Central Marine Fisheries Research Institute, Cochin

4.1 Introduction

The devastating tsunami that struck the Indian coast on the early hours of 26

December 2004 has dealt a severe blow to the coastal marine fisheries sector causing a

huge loss of men and material. The livelihood security of lakhs of coastal rural folk who

are directly or indirectly dependent on marine fisheries has been shattered by destruction

of their dwellings and more importantly their only means of earnings, namely, the craft

and gear. The Anadaman & Nicobar Islands were the worst affected and among the

coastal states, Tamil Nadu and Pondicherry suffered the worst damage, some parts of

Kerala and south Andhra Pradesh also experienced loss of human lives and property.

The loss to the aqua culture sector extends even to the onshore infrastructure such as the

shrimp hatcheries, that will affect the shrimp seed production and farming. Most Indian

aqua farms are owned and managed by small/marginal farmers whose capability to

recover from such a disaster is very low. Many hat,chery facilities in the southern India

regions were severely affected. While the second harvest had been completed, farm

infrastructure has been badly damaged and this is likely to have an impact on future

shrimp production. One of the major concerns is the availability of adequate brood

stock(the mother shrimp) from the wild in the context of reduction in fishing due to the

tsunami. Though the initial reports have indicated that the export capability of the sea

food industry may not have been seriously hit by the tsunami, later assessments have

shown extensive damage to the sector. Immediately following the natural disaster, the

Central Marine Fisheries Research Institute had made an assessment of the extent of

damage caused to the marine fisheries sector and studied the structural changes that took

place both on and off-shore. The results of assessment survey on Kerala coast is

summarised below.

4.2 Loss

As per the official figures released by the Ministry of Home Affairs the number of

losses of human lives, population affected, villages affected and s\dwelling affected in

Kerala are as follows :

Villages/Islands affected 187

Population affected 2470

Dwellings affected 11832

Human lives lost (Missing) 176

4.3 Marine fisheries

In the Kovalam, Marakanam and Pondy belt in Tamil Nadu, most of the shrimp

hatcheries have lost their pump houses, fencing etc.

Parts of Alappuzha and Kollam districts were severely hit by the tsunami and the

estimated loss to the marine fisheries sector was assessed at Rs.1000 million, the

mechanized sector accounted for 64% of the total loss. Nearly 10,880 fishing craft (18%

of the craft operating in the state) have been destroyed or damaged. The loss due to

destruction of fishing nets was anout Rs.3.7 million. The average annual production from

this state is about 6 lakh tones and a decline to the tune of 5-10% is anticipated during the

current year. The expected loss in revenue from the marine capture fisheries is estimated

to be Rs.350 crores, at the landing center price.

Total loss in the aquaculture sector is estimated around Rs.15 million. At least 14

shrimp hatcheries have been affected covering 4 districts (Kollam, Allapuzha,

Eranakulam and Kannur).

4.4 Change in Topography

The impact of the killer waves was more evident in coastal areas within 0.5 km from

shoreline and to a lesser extent between 0.5 and 2 km. Fishermen in Kerla have reported

that the bottom topography of the trawling grounds has been altered and dislodged

boulders and rocks hinder trawling. A change in the bottom topography may affect

feeding and breeding grounds of the benthic community. In many parts, fish have been

involuntarily transported along with tidal waves as has been reported from Arattupuzha

where huge quantities of small oil sardine (100-150 mm) were landed by ring seine units

subsequent to tsunami. Significant hydrological variations can affect the reproductive

cycle and breeding of fish varieties.

4.5 Trade

India's seafood exports, which were worth nearly $2 billion in 2004, are expected

to decline by 30% in 2005 because of the tsunami disaster. The US decision to impose

anti-dumping sanctions on Indian shrimp imports dealt another blow to India's seafood

industry. Improved access to US markets is now even more vital for the recovery of

South India's export-oriented fishing industry that has suffered extensive damage in terms

of lost lives, boats, gear, and infrastructure, shrimp farms inundated, and aquaculture

hatcheries destroyed. This will adversely impact the sea food industry, undermining its

shrimp, cephalopods and fin-fishes exports in the short run. There has been widespread

welcome for US government's recent announcement of a review of its ant-dumping duty

on imports of shrimp from India in order to provide relief to the fishing communities

affected by the tsunami. The damage caused by the tsunami in India demands

considerable humanitarian approach to alleviate social and economic damage specifically

with reference to the fishing industry and shrimp aquaculture sector.

4.6 Reconstruction and management

Fisheries management strategies have to consider short term and long term

ramifications of natural disasters such as the tsunami. While the consequences of

disasters like the tsunami are not entirely preventable, it is possible to reduce their effect

so that fewer lives are lost, fewer livelihoods destroyed, and ensure sustainability. Now is

the time to assess the vulnerability of coastal communities and to determine how to

reduce it in ways that lead to durable solutions. The Coastal Regulation Zone (CRZ)

notification of 1991, which regulates development activities on the coast of India, may

need to be strengthened and enforced to protect the coastline more effectively from

environmental degradation as a result of unplanned and excessive development, and to

reduce the risk of future coastal disasters. The state coastal zone management authorities

(CZMAs) must enforce the CRZ regulations on intensive or large-scale developments

within 500 meters of the shore, but without impoverishing and evicting poor communities

who live on the coast. Therefore, the Government of India should ensure that coastal

communities are consulted and that an assessment of the impact on coastal livelihoods

and on poverty is undertaken before taking action to relocate them.

4.7 CMFRI initiative Fallouts of the tsunami onslaught were manifold. Fishing activities were badly hit

and fish production recorded a steep fall. False rumours on seafood safety crippled fish

trade. Director and senior scientific personnel from the CMFRI attended press

conferences and took part in seafood festivals organized by Fisheries Industry Protection

Council to alleviate the public fear of consuming fish. These programmes, which had

wide media coverage, helped to dispel concern on safety of seafood.

The multi-dimensional impact of tsunami on fisheries and fish habitats demands a

detailed study. The CMFR Institute has initiated studies on changes in the coastal

biodiversity and environment of tsunami affected regions of the mainland and Andaman

& Nicobar Island system as well as its impact on fish stocks. Network projects are also in

place to examine the post-tsunami microbial and chemical hazards in seafood. Further,

socio-economic impact assessment of tsunami alongwith case studies of restoration

models is being undertaken along the Indian coasts. Studies on developing sustainable

models of fish aggregating devices to reduce the impact of tidal waves are also on the

anvil. In view of the importance of mangroves as bio-shield, the institute has initiated

projects on mangrove eco-system for conservation and management. It is anticipated that

the first results of the above studies are available within six months, which would give a

clear insight into the impacts of the catastrophe on coastal fisheries and livelihoods. The

Institute plans to give support for alternate livelihood activities to fishers and guidance in

their rehabilitation programmes along the tsunami-affected coastline of India.

4.8 Conclusion

The Government of India launched a huge relief operation involving the central

government (Armed Forces, Ministry of Civil Aviation, Ministry of Home Affairs, etc.)

as well as the State Governments of Tamil Nadu, Andhra Pradesh, Kerala, the Nicobar

group of Islands and the UT of Pondicherry. The focus is on relief, rescue and

rehabilitation. The teams have representatives of the Department of Revenue,

Agriculture, PWD, Police, Fishery, Animal Husbandry and Civil Supplies. All the islands

have been surveyed and relief supplies have started arriving.

The challenge ahead is to ensure effective assistance to nearly three million

people in India who have been affected by the tsunami. They have lost their homes, or

their livelihoods, or both. More than one million people have been displaced and are

currently living in safe places, including temporary shelters. The figures for property

damaged are staggering: 160,000 houses have been destroyed; more than 10,000 cattle

have died; 64,000 boats have been lost or badly damaged; and 12;000 hectares of

farmland are in a state of disrepair. In the light of the above reported losses in the various

sub-sectors of fisheries and also considering the fact that fishermen have no other skills

or means of livelihood, it will take long time for them to resume their vocation. The

Asian Development Bank estimates that the number of people living in poverty in India

could rise by 645,000. The tsunami disaster of December 2004 forcefully demonstrates

that a principal cause of poverty in India is people's vulnerability to such natural

disasters, which is why it is essential that effective disaster management be integrated

into long-term development in order to reduce'the human and economic costs of such

events.

4.9 Marine fish landings (‘000 t) in Kerala during the first quarters of 2004 &

2005

Marine fish landings in Kerala during the first quarter of 2005 show a decreasing

trend (18.7%) when compared to that of 2004. Landings of Oil sardine decreased by

3.5% during 1st quarter of 2005 when compared to 1st quarter 2004. Landings of peches

decreased by 37.8%, crockers by 19.2%, Ribbonfishes by 56.3%, carangids by 41.1%,

Silverbellies by 35.4%, Non-penaeid prawns by 85.4%, crabs by 1.3% and cephalopods

by 54%. Landings of mackerels increased by 0.8%, Penaeid prawns by 1.1% and

Flatfishes by 29%.

The catch per unit effort (CPUE) during the first quarter of 2005 is 213kg and that

during 1st quarter 2004 is 250 kg which also shown a decreasing trend. Actual fishing

hours (A.F.H.) has also decreases (3.5%).

There is no change in specific composition.

Name of fish 1st Qr 2005 1st Qr 2004 % differenceOil sardine 43.2 44.8 -3.5Perches 10.0 16.1 -37.8Croakers 1.6 1.9 -19.2Ribbon fishes 0.3 0.8 -56.3Carangids 5.3 9.1 -41.1Silverbellies 0.7 1.2 -35.4Mackerels 4.9 4.8 +0.8Penaeid prawns 12.0 11.9 +1.1Non-penaeid prawns 0.7 4.6 -85.4Crabs 2.8 2.9 -1.3

Grand Total 121 149 -18.7

Effort (units) 569352 596749 -4.6A.F.H. 2611494 2707341 -3.5CPUE 213 kg 250 kg

4.10 Socio-Economic Impact of Tsunami in Kerala

Tsunami and its associated destruction constituted one of the worst humanitarian

tragedies in India. The socio economic impact of the disaster is highly localized and felt

more starkly at the level of numerous affected communities. Tsunami caused substantial

destruction and casualties in the coastal regions of the states including Tamil Nadu,

Kerala, Andhra Pradesh, Pondicherry and Andaman Nicobar Islands. The Socio

Economic Evaluation and technology Transfer Division (SEETTD) of CMFRI has

conducted a detailed socio economic impact assessment study in the worst affected

regions of Kerala such as Alappad in Kollam district, Arattupuzha and Andhakaranazhi

in Allapuzha district and Edavanakkadu in Eranakulam district.

In Kerala, 187 villages were affected by the roaring waves. The disaster devasted

communities with its high toll on human lives (176 persons), injuries, family networks,

homes and livelihoods. Like all the other Tsunami affected states, women and children

constituted majority of the victims in Kerala. Fisher folk were the most affected segment,

which endured damage due to loss on housing and livelihoods. The disaster will not

have any significant impact on Kerala’s GSDP growth. However, the loss of life,

damage to physical infrastructure and economic foundations in the coastal districts has

localized impact on the coastal economy. On the basis of the assessment of damages by

tsunami in Kerala, the impact and issues in fisheries, agriculture, livestock, housing,

health and overall livelihood is discussed below.

4.10.1 Housing and related issues

The tsunami caused widespread damage to shelter and housing. Almost 1,54,000

houses were either destroyed or damages entailing losses of about Rs.994 crore. Almost

all the affected housing in Kerala was of pucca category. A large number of affected

households were living on the government land without title (encroachers). This has

posed many problems associated with rehabilitation. As part of the protection from the

disasters, relocation of a number of families was recommended, by strictly adhering to

Coastal Zone Regulation (CRZ). But this issue has gathered momentum on the grounds

that most of the fisher families live within the CRZ even before adoption of this measure

and resettlement of all these families by strictly adhering to regulations would involve

much effort and resources.

Fishermen communities are reluctant to have their resettlement at more than 800

meters to 1 kilometer from the existing location or from the sea. Further the land

availability is a problem as most villages are narrow strips of land between sea and

backwaters, most of them having width of not more than 2 kilometers. Displaced

households with legal title demanded that the government should provide them new land

with title while allowing them to retain the rights to original property. The biggest

problem in the affected area is the availability of drinking water. Following the disaster,

wells were buried in sand and water in the wells that survived had turned saline. Also

water pipe connection in temporary shelters did not serve the purpose forcing people to

depend upon other sources of fresh water.

Power supply to these areas was disrupted which needed to be taken up with at

most priority. Government has introduced temporary rehabilitation arrangements by

providing shelters made by Nirmiti Kendra using Galvanized Iron Sheets. But these

dwellings turn extremely hot during daytime making it unable to live in. Also the

sanitation arrangements made nearby are not sufficient and it is posing threat to health of

inmates of temporary shelters. Permanent housing offered by various agencies are not

yet completed or is still in the process or in the initial stages due to various issues related

to rehabilitation including adherence to CRZ and reluctance of people to move away

from their original place of inhabitance.

4.10.2 Fisheries

An assessment of the damage to assets and losses in fisheries sector showed a

total loss of Rs.117.8 crore (Joint Assessment Mission Report). The estimated value of

losses in mechanized sector was Rs.64 crore, whereas it was Rs.16 crore in motorized

and Rs.20 crore in non-mechanized sector.

The average landings pattern of fishes before and after tsunami is given in Table

1. Immediately after the tsunami, fishing operations along the coastal regions came to a

stand still. Few fishermen who ventured into fishing restricted their activities near to the

shore. Hence there was drastic reduction in the per capita landings of all types of fishing

units. As a whole, the average landings, pertaining to a month succeeding tsunami has

recorder one-third reduction for all types of fishing units. A comparison between the

average catch in a month before and after tsunami gives a clear decrease of landings. In

this study pre tsunami period indicates a time period of one month from 16th November to

15th of December and post tsunami period is from 16th of January to 15th of February.

Table 1. Landings of Marine fishes in Kerala before and after tsunami

Average landings (boat/day) Pre tsunami Nov-Dec*

Post tsunami Jan-Feb*

Sl.No.

Type of craft gear combinations

Q (Kg) Q (Kg) Motorized

1 Plank built boats with gillnet 83 35

2 Plywood boats with gillnet 26 15

3 Catamarans with gillnet 75 50

4 Canoes with ring seines (out board) 650 490

5 Plank built boats with ring seins (in board) 875 625

6 Canoes with mini trawl nets 50 40

Non-mechanized

1 Catamarans with gillnet 41 27

2 Small canoes with cats nets 5 4

3 Country crafts operating with gillnet 18 4

* For a preceding and succeeding month

(Source: Socio Economic Evaluation and Technology Transfer Division (SEETTD), CMFRI,

Kochi)

In case of motorized boats, decline in fish catches was observed to the order or 25

to 68 per cent. In motorized category, plank built boats with gillnets experienced utmost

decrease (58 per cent) in catches compared to pre tsunami period whereas in case of non-

mechanized category, country crafts with gillnet was affected with maximum reduction

(78 per cent) in landings. The decrease in ladings is mainly due to destruction of fishing

vessels as well as reluctance of fishermen to go to their fishing grounds.

The details of number of trips per month before and after tsunami are given in

Table 2. It took a long time to restore normal living conditions and no fishing activities

were undertaken immediately after tsunami. This was mainly due to loss of fishing

equipments; fear of recurrence of tsunami and displacement from their original place of

inhabitance to relief camps. The number of fishing trips of boats in a month came down

by 20 to 60 per cent compared to the pre tsunami situation. Fishing trips of motorized

boats were more affected than the non-mechanized category. The number of fishing

trips, which ranged from 20-25 days before tsunami, was reduced to the level 10-12 days.

Maximum reduction of fishing trips was seen in the case of country crafts with gillnet

and canoes with ring seines (60 per cent). In the non-mechanized category, the fishing

trips were reduced by 20 per cent to 40 per cent. Utmost slump in fishing trips occurred

for catamarans with gillnet.

Table 2. Number of fishing trips per month for various craft-gear combinations

Number if fishing trips Sl.No.

Type of craft gear combinations Pre tsunami

Nov-Dec* Post tsunami Jan-Feb*

Motorized

1 Plank built boats with gillnet 25 12

2 Plywood boats with gillnet 25 10

3 Catamarans with gillnet 22 12

4 Canoes with ring seines (out board) 25 10

5 Plank built boats with ring seins (in board) 20 10

6 Canoes with mini trawl nets 25 12

Non-mechanized

1 Catamarans with gillnet 25 15

2 Small canoes with cats nets 25 20

3 Country crafts operating with gillnet 25 20

* For a preceding and succeeding month

(Source : Socio Economic Evaluation and Technology Transfer Division (SEETTD), CMFRI,

Kochi)

Table 3. Average per capita income of the Boat owners

Net income of Boat owners (Rs/day)

Sl.No.

Type of craft gear combinations

Pre tsunami Nov-Dec*

Post tsunami Jan-Feb*

Motorized

1 Plank built boats with gillnet 317 192

2 Plywood boats with gillnet 233 167

3 Catamarans with gillnet 292 183

4 Canoes with ring seines (out board) 2333 1740

5 Plank built boats with ring seins (in board) 3125 2250

6 Canoes with mini trawl nets 647 510

Non-mechanized

1 Catamarans with gillnet 162 105

2 Small canoes with cats nets 57 55

3 Country crafts operating with gillnet 100 33

* For a preceding and succeeding month

(Source : Socio Economic Evaluation and Technology Transfer Division (SEETTD),

CMFRI, Kochi)

Very likely as implied by the outcome of the Tables 3 & 4, the income levels of

boat owners operating and non-operating as well as the crewmembers showed a steep

decline. In the motorized category, the significant reduction in average value of catch per

day of operation for different categories of craft gear combinations was noticed. The

average income of boat owners of motorized categories that varied from Rs.233 to

Rs.3125 before tsunami came down to the range of Ts.167 to Rs.2250. The maximum

reduction in boat owners income was experienced for plank built boats with gillnet (40

per cent) and minimum was in the case of canoes with mini trawl nets (21 per cent) in the

motorized category. Pre tsunami income pf boat owners in the articanal sector ranged

between Rs.57 to Rs.162 while it reduced to the order of Rs.33 to Rs.105 in the post

tsunami period. In the artisanal sector, country crafts with gillnet suffered from 67 per

cent reduction in income whereas small canoes with castnet had only 3 per cent

reduction.

Table 4. Average income of the fishing labourers

Income of fishing labourers (Rs/day)

Sl.No.

Type of craft gear combinations

Pre tsunami Nov-Dec*

Post tsunami Jan-Feb*

Motorized

1 Plank built boats with gillnet 79 48

2 Plywood boats with gillnet 58 42

3 Catamarans with gillnet 292 183

4 Canoes with ring seines (out board) 69 51

5 Plank built boats with ring seins (in board) 69 50

6 Canoes with mini trawl nets 216 170

Non-mechanized

1 Catamarans with gillnet 41 26

2 Small canoes with cats nets 57 55

3 Country crafts operating with gillnet 100 33

* For a preceding and succeeding month

(Source : Socio Economic Evaluation and Technology Transfer Division (SEETTD),

CMFRI, Kochi).

In case of fishing labourers, who were to share one third of the total revenue of

the catch, suffered from heavy losses after tsunami. The average income of fishing

labourers of motorized categories that varied from Rs.58 to Rs.292 before tsunami cam

down to the range of Rs.42 to Rs.183. The maximum decline in fishing labourers income

was experienced for plank built boats with gillnet (40 per cent) and minimum was in the

case of canoes with mini trawl nets (21 per cent) in the motorized category. Pre tsunami

income of fishing labourers in the artisanal sector varied between Rs.41 to Rs.100, while

it reduced to the order of Rs.26 to Rs.55 in the post tsunami period. In the artisanal

sector, country crafts with gillnet endured maximum (67 per cent) drop in income of

fishing labourers whereas small canoes with case net had only 3 per cent reduction.

Both categories, viz boat owners and fishing labourers are finding it difficult to

meet their living expenses with the drastic reduction in their income. The fishing

operations are gradually becoming non profitable since the diminishing returns that are

just sufficient to meet the operating costs. Also there was a tremendous drop in the

average number of fishing days. Moreover, the fishing labourers who are already in the

clutches of the moneylenders and traders from whom they had borrowed money is

finding it difficult to cope up with the situation. The government is providing grants to

the affected population in order to sustain the lives of fisher folk in the absence of their

livelihoods.

Table 5. Average price for different species of marine fishes before and after

tsunami

Price of fish (Rs/Kg) Sl.No.

Species Pre tsunami

Nov-Dec* Post tsunami Jan-Feb*

1 Oil Sardine 15 7

2 Mackerel 35 15

3 Anchovies 50 20

4 Soles 15 5

5 Tuna 35 12

6 Horse Mackerel 20 8

7 Croakers 40 15

8 Crab 30 10

9 P.stilifera 55 42

10 M.dobsoni 85 65

11 Seer fish 140 80

12 Barracuda 50 20

13 Shark 45 30

14 Caranx 60 25

15 M. monoceros 175 125

* For a preceding and succeeding month

(Source: Socio Economic Evaluation and Technology Transfer Division (SEETTD),

CMFRI, Kochi).

The prices of marine fish also faced set backs immediately after the tsunami. This

was mainly due to low demand for fishers in the market, due to apprehension of people,

that fishes might have consumed carcasses of humans and animals lying in the sea after

the tsunami. Another reason for low demand was the reduction in the size of fish after

tsunami. The prices of selected species of fishes before and after tsunami are given in

Table 5. In the case of most of the species, post tsunami price was reduced to less than

half of its pre tsunami price. The reduction in price was utmost in case of soles (67 per

cent), crab (67 per cent) and tuna (66 per cent). Due to reduced demand for fish for

consumption, the fish catches were dried and made use for making livestock feeds.

4.10.3 Other related issues

Damage to agricultural sector is mainly confined to the destruction of standing

crops like paddy, coconut, banana, vegetables etc. Intrusion of seawater into productive

fields has caused deposition of infertile sediments, salinity and water logging. The

damage to soil is semi permanent in nature, lasting until the monsoon rain naturally

flushes out salt. The livestock sector offering supportive livelihoods was affected by

Tsunami. The death of animals and damage to pastures, damage to paddy (affecting

straw available) were the negative impact affecting livestock population. A number of

poor families, especially, the female members, had taken up livestock rearing as an

alternative avocation contributing to an additional income for the family. Also the

coastal population adopted subsistence type of farming of vegetables. The disaster has

taken away this income, increasing the vulnerability of those affected.

In health care sector, tsunami unleashed destructive impact on infrastructure,

which affected the movement of immediate relief measures after disaster. In Kerala, two

Primary Health Centre’s were damaged in Alappad region in Kollam District. The

affected communities were sheltered in relief camps and preventive and curative

measures in order to check the outbreak of any contagious diseases. No such instances

were reported from the relief camps.

4.10.4 Livelihood related issues

Tsunami has resulted in income and wage loss of directly and indirectly affected

households. The major livelihood activities in the coastal areas are fishing, agriculture,

livestock and non-farm activities.

Fisheries sector provides secondary employment opportunities apart from capture

and culture fisheries. This includes net mending and weaving, supply and repair of

fishing equipment and gear, boat building, provision of ice, marketing, processing and

transporting of fish, fish exports etc. Labourer’s engaged in these activities seems to be

in abject poverty, having no reserves to fall back upon. The damages to homes,

destruction of village infrastructure and loss of lives of family members have

compounded the problems. These damages are accentuated by prevailing issues in the

fisheries sector that relate to rising input cost, especially fuel, declining profitability of

small boat owners, inequitable distribution of market value of produce and in some

instances depleting fishing stock.

The infrastructure losses in fisheries are not yet compensated/restored severely

affecting the livelihoods of coastal population. However, government is continuously

providing the basic necessities as to the requirements of food, shelter and medicines. A

monthly grant of Rs.1000 is paid to the affected families in the temporary shelters as a

provision for substance. However, people are developing a reluctant attitude to work due

to delay in restoring infrastructure in fisheries sector. Building of permanent shelters is

in the process and several agencies have come forward to provide their contributions.

A number of female-headed households are left after the tsunami due to loss of

lives of male counter parts. They are having a tough time as they are the primary care

takers of small children and do not have an alternative to go out for earning an income for

the family. They have to deal with their own psychosocial distress, loss of livelihood and

care for their dependents.

Coastal community depends heavily upon various financial sources. They are

highly indebted to categories like traders and village moneylenders that have accentuated

the vulnerability of these communities. Livelihoods are not restored at least to the pre

tsunami level or alternative avocations are not adopted successfully. However

Government is supplying a contingency grant of fixed amount, which has imbibed a

culture among the victims to wait for the government or other agencies to act.

A considerable number of affected families, particularly women members were

undertaking activities by involving in micro enterprises. These enterprises cater to the

local markets and to the local population for both inputs and outputs. They have been

severely affected through the loss of equipment and loss of other assets and loss of

employment etc. that have deprived associated families of an additional income.

Moreover these Self Help Groups had availed loans from financial institutions, and the

repayment of such debt is under doubt due to extensive damage caused. The

beneficiaries have appealed to the government to write off such debts as a relief measure.

Wage labourers, seasonal workers and other subsistence activities are undertaken

by the most vulnerable section in the coastal community. Poverty incidence in such

sections is also very high. Disaster has added to the vulnerability of such sections due to

loss of employment.

Damage to agriculture and livestock is confined to immediate vicinity of the

coast. Damage includes loss of standing crops and death of livestock, which has

significant impact on the livelihoods of the poor, especially women. In addition,

disturbances caused by the disaster to soil fertility will result in long-term negative

impact on agriculture indirectly affecting those employed in this sector.

In order to reinstate the standard of living of the fisher population, necessary back

up designed towards capacity building, by empowering the fisher folk, providing

facilities like alternative income generating avocations and adequate support to restore

fishing activities should be undertaken by the Government and other agencies.

Chapter V

IMPACT STUDIES ON NEARSHORE AND BEACH AREA Centre for earth science studies

Thiruvananthapuram

5.1 Introduction

The December 2004 tsunami generated by the Sumatra-Andaman earthquake

unleashed terrible calamity along the shores of many Indian Ocean countries and had a

devastating impact on the Kerala coast too. Centre for Earth Science Studies initiated

several studies for understanding and documenting the impact of this tsunami on the

coast and inner shelf and documenting the characteristics of the tsunami onslaught. Post-

tsunami field surveys were undertaken to estimate the runup level for beach profiling,

bathymetric survey and sedimentological investigations. Wherever pre-tsunami data was

available, impact due to tsunami has been assessed. This report presents the results of the

investigations carried out so far. The topics covered under this report are;

1. Run-up Level for the whole Kerala Coast

2. Beach Profile variations in the worst affected Kayamkulam region

3. Innershelf profile changes off the Neendakara-Aratupuzha coast

4. Changes in sediment characteristics in the innershelf off Neendakara-Thotapalli

coast

5.2 Run-up Level Estimation for the Whole Kerala Coast

5.2.1 Methodology

During the post-tsunami days, starting from 27th December, field visits were

conducted at different locations of Kerala coast. The Post-Tsunami Survey Field Guide

published in the web site of International Tsunami Information Centre (ITIC) was taken

as a guide in the field trip. Considering the geomorphic set up of the coast, the run-up

was estimated as the elevation at the local maximum of the horizontal inundation

measured relative to mean water level at each location (Page 13, ITIC Tsunami

Glossary). Altogether 83 locations spread all over the Kerala coast, reported to have been

affected by the tsunami, were visited. For estimation of run-up level, field signatures such

as trapped floating objects in plants/trees/ buildings, flood mark or damaged windows

and doors of buildings, etc. were relied upon. In addition, local people were also

interviewed to collect eye-witness reports. Information such as arrival time and height of

different waves, inundation characteristics, nature of damage and causalities, etc., as

listed in the Field Guide was recorded.

5.2.2 Results

The run-up level distribution shows wide variations along the coast (Fig.1). In the

Pozhiyur to Vizhinjam (southernmost) sector, the run-up level was only upto 1.5 m,

where as in the Vizhinjam – Varkala sector it was 2- 2.5 m. In the Thangasseri harbour

area of the Kollam coast, the run-up was about 2.5m, where as in the segment to its north,

it was upto 3 m. The run-up level increased further north, reaching about 3.5m. In the

Cheriyazhikkal area, run-up upto 4.5m is reported. In Azhikkal and upto Kayamkulam

inlet, the severity of attack of tsunami was the highest with run-up upto 5 m.

In the sector immediately to the north of Kayamkulam inlet also the tsunami

onslaught was severe with run-up level upto 5.0 m. Further north, in the Arattupuzha

region and upto Thottappally, the run-up level reduced to 3.5m. From Thottapally

onwards there was a further decrease till south of Anthakaranazhi inlet. In the zone

around Anthakaranazhi inlet, there was an increase in the run-up level reaching upto 3.5

m. Further north, in the Chellanum-Puthuvype region around Cochin, run-up level

decreased to 3 m. However, in the Edavanakkad region, the run-up level increased

drastically and went upto 4.5 m. There was a reduction in the run-up level further north

with a drastic reduction in the zone immediately north of the Munambam inlet. However,

further north the level increased showing upto 3 m around Vadanapally. There was a

drastic decrease in the sector south of the Ponnani inlet. An increase in the level was

found north of Ponnani inlet. Run-up level upto 2.5m was found at Beypore inlet, south

of Calicut.

In the northern parts of Kerala coast comprising of Kozhikode, Kannur and

Kasaragod districts, the run-up levels were generally low, up to 2.5m. However, a short

sector around Choottad was notable for a high run-up level of 3 – 3.5 m which was not

reported anywhere in the northern Kerala. A short sector north of Nandhi and the

Kanhangad-Manjeswaram sector showed run-up level of only upto 1.0 m.

5.2.3 Conclusions

The run-up level distribution along the Kerala coast generally showed a

northward decrease from Kayamkulam inlet, which recorded the highest level of 5.0 m. It

is deduced that the observed distribution could be due to wave transformation processes

viz. diffraction, reflection, shoaling and refraction coupled with the interaction process of

the tsunami waves with tide, wave and current. The superimposition of tsunami waves

with high tide was a factor that compounded the inundation, leading to higher intensity of

damage around Kayamkulam. Simultaneously, the low tide minimized the effect, as

observed in the northern tracts of the coast, where the tsunami arrived in the afternoon.

The highest waves along the northern Kerala coast occurred at midnight, coinciding with

the next high tide and the occurrence of two major waves at that time.

5.3 Beach Profile Variations 5.3.1 Methodology

In order to understand the impact of tsunami on the beach morphology, post-

tsunami beach profiles were measured at 5 stations in the sector north of Kayamkulam on

14th January 2005 and 4 stations south of Kayamkulam inlet, the subsequent day. For

these stations, pre-tsunami beach profiles taken in 16th November 2004 were avaialble

and the reference stones were still intact without any damage due to the tsunami. Beach

profile measurements were carried out using the standard level and staff method.

5.3.2 Results

The beach profiles are presented in Fig 2. The volume changes computed from the

beach profiles are presented in Table 1. At N1 (just north of Kayamkulam inlet) nearly 53

m3 of erosion took place whereas at N2, further north of N1, an erosion of 16 m3 was

noticed. The highest quantum of erosion has taken place at N3 which is 2km north of the

inlet. At N4 and N5 (which are further north of the inlet) through erosion took place, the

quantum was much less. At S1, on the southern side of the inlet adjacent to the

breakwater, high quantum of deposition equal to 91 m3 was noticed. At S2 about 200m

south of the inlet, erosion equal to 38 m3 had occurred . However, at S3, about 1km south

of the inlet, deposition of 65 m3 was seen. At S4, further south of the inlet, a modest

deposition of 13 m3 was assessed

Table: 1 Volume changes at different stations adjoining the Kayamkulam inlet

Sl.No Station Status Volume change

(m3 /m width of beach)

1 N1 Erosion 53.4

2 N2 Erosion 16.1

3 N3 Erosion 66.5

4 N4 Erosion 4.0

5 N5 Erosion 7.3

6 S1 Deposition 91.4

7 S2 Erosion 38.1

8 S3 Deposition 64.8

9 S4 Deposition 12.6

Run-up Level

N N

Thalai Beach

KASARGODEKanjhangad

Ayikkara

ChoottadValiaparamba

CANNANNORE

Manjeswaram 1 2N

Puthiappa

Ponnani

Beypore

Nandhi

MALAPPURA

CALICUT

Ayithala

Fig 1: Runup level distribution along the Kerala coast

N

TRICHUR

Ponnani

Edavanakkad

Munambam

Vadanapalli

Puthuvypin

3 4

Arattupuzha

Thottapalli

Anthakaranazhi

Mararikulam

Chellanam

NCOCHIN

ALLEPPEY

Kayamkulam Inlet

5

N

Thangasseri QUILON

Azhikkal

Pozhiyur

Vizhinja

Veli

Perumathur

CheriazhikkaSakthikulanagara

Varkala

Paravur

TRIVANDRU

5.3.3 Conclusions

The erosion/deposition pattern obtained to be viewed in the backdrop of the

coastal sedimentation processes prevalent in the area. The breakwaters at the inlet,

jetting out into the sea is acting as a groin, ever since the construction started a couple of

years ago.

Thus, huge accretion has been taking place in the southern side of the inlet due to

the predominant northerly longshore currents during fair weather. Erosion has been

taking place in the northern side due to the groin effect of the breakwater. In the present

case, the pre-tsunami beach profiles were taken on 14th November, 42 days before the

event. Thus the beach in the southern side of the inlet must have got considerably

accreted with respect to the pre-tsunami profile and thereafter till the post tsunami beach

profiling on 15.01.2005. The field signatures on both the sides of the inlet showed

scouring and erosion. However, the erosional effect of the tsunami was not sufficient

enough to offset the depositional trend in the southern side except at station S2. In a

similar way, the erosion observed in the northern side may not be entirely due to the

tsunami.

N5Distance from reference point

-4

-3

-2

-1

00 20 40 60 80

Distance (m)

Ele

vatio

n (m

)

N4Distance from reference point (m)

-5

-4

-3

-2

-1

00 20 40 60 80

Distance (m)

Ele

vatio

n (m

)

N4 N5

)

Jan 2005Nov 2004

N

S

NS

S4

-4

-3

-2

-1

0

1

0 20 40 60

Distance (m)

Ele

vatio

n (m

S2

-4

-3

-2

-1

0

1

2

0 50 100 150

Distance (m)

Ele

vatio

n (m

)

S3

-5

-4

-3

-2

-1

0

1

0 50 100 150

Distance (m)

Ele

vatio

n (m

)N1

-4

-3

-2

-1

0

1

2

0 20 40 60 80

Distance (m)

Ele

vatio

n (m

)

S I

-4

-3

-2

-1

0

1

2

0 50 100 150 200 250

Distance (m)

Ele

vatio

n (m

)

N3

-5

-4

-3

-2

-1

0

1

0 20 40 60 80

Distance (m)

Ele

vatio

n (m

)

N2

-3

-2

-1

0

1

0 20 40 60

Distance (m)

Elev

atio

n (m

)

S4

N3

N1 S1

S2 S3

N2

Fig 2: Beach profiles along Kayamkulam sector

5.4 INNERSHELF PROFILE CHANGES AND SEDIMENT

CHARACTERIZATION (Dr.T.N.Prakash)

5.4.1 Methodology

A Bathy-500DF echosounder was used for depth measurement and preparing the

bathymetric map of the offshore area. Position fixing during the bathymetric survey was

carried out using a Leica DGPS system. The echo sounder and DGPS were integrated

through a Hydrographic Software and survey was carried out along transects using the

software. The bathymetric survey was carried out during March-April 2005 along

transects at 1 km interval limited to 50 m water depth.

Besides the profile changes, innershelf sediment characteristics were also studies

– surficial sediment samples analysed.

Surficial sediment samples were collected as part of another study initiated during

the period at CESS (CMRI project, 2005). As part of this study, 110 surficial sediment

samples were collected at different transects limited to 50 m water depth off Neendakara-

Thottapilli coast and analysed.

5.4.2 Results

The bathymetric chart prepared for the area is given in Fig.4. The bathymetric

data available for 2000 (Kurian et al., 2002) were also plotted on the same map for

computation of change in the depth which could indicate the impact of Tsunami. Since

innershelf profiles barring the nearshore zone are usually not amenable to any significant

changes, it is reasonable to assume that the changes noticed correspond with the tsunami

effect. The preliminary analysis indicates that there is a shifting of depth contours

towards shore indicating erosion of sediments and deepening of innershelf due to the

tsunami. It can be seen that, in general, the displacement of the contours increases

towards shore.

The coarse sediment distribution pattern from this study and the historical data in

the innershelf are shown in the Fig.5.

The distribution pattern is almost similar except that a small sandy patch off

Kayamkulam between 30 and 40m water depth has shifted towards shore, which is

corroborating with the erosion reported from the bathymetry survey.

5.4.3 Conclusion

The bathymetric survey confirms the erosional tendency of the tsunami waves.

As in the case of beach, erosion is noticed in the innershelf also. The sediment

distribution pattern correlates the findings of bathometric resources. The preliminary

results indicate changes in the innershelf sediment characteristics with shoreward

migration of sandy patch off Kayamkulam

640000 645000 650000 655000 660000 665000970000

975000

980000

985000

990000

995000

1000000

1005000

1010000

1015000

640000 645000 650000 655000 660000 665000970000

975000

980000

985000

990000

995000

1000000

1005000

1010000

1015000

Kayamkulam Inlet

Vellanathuruthu

Neendakara Inlet

Vallikkavu

Thangasseri

2005Shoreline

20002005Shoreline

2000

Fig.4 Comparison of depth contours in the tsunami affected coast

a) Thottapa

Tottappalli

76.1 76.2 76.3 76.4

b)

Neendakara

Kayamkulam

KOLLAM

9.3

9.2

9.1

90

8.9

76.776.676.5

Coarse Sediment Distribution

90

80

70

60

50

40

30

20

10

5

Fig.5. The distribution of sand in the inner shelf (a) during 1987 & (b) during 2005

5.4.4 Acknowledgements

These studies were supported by the Department of Science and Technology.

CHAPTER VI

EFFECT OF TSUNAMI ON THE QUALITY OF GROUND WATER Kerala State Ground Water Department

6.1 Introduction

On December 26, the earthquake set off giant tsunami waves of 3 to 10 meters in

height, which hit the southern and eastern coastal areas of India and penetrated inland up

to 3 km, causing extensive damage. In Kerala, of the 176 people who died along the 590-

km-long coast, 158 were from two villages – Alappad in Kollam district in the south and

Arattupuzha in Alappuzha district in the north.

The two villages share a distinctive geography, sandwiched as they are between

the sea and the backwaters of Kayamkulam. Both are thickly populated, especially on

either side of a coastal road that barely separates the lake from the sea. Both are rich in

mineral sands and have a long bridge at one end and ferryboats at the other end, the only

links across the lake to the mainland. Both are idyllic coastal locations, serenely tucked

away from the mainstream bustle of Kerala. But this uniqueness also makes them among

the most vulnerable dangerous places to be in, when a tsunami strikes.

In the affected areas, the main sources of drinking water are ponds and dug wells.

The sources got contaminated due to mixing of seawater, leading to the scarcity of

drinking water. Reports from the tsunami affected coastal areas of Tamil Nadu indicate

that the groundwater near the coastal area (up to approx 500 m) became highly saline.

Salinity increased 10 to 100 fold. The open wells got completely overwhelmed.

We still have only a limited picture of the implications of the present and long-

term impact on ground water resources. The technical issues are complex, the source

data for many of the regions are poor and survey work after the event has been

piecemeal.

6.2 Methodology

Just after the Tsunami attack, ie. at the end of December 2004/beginning of

January 2005, water samples were collected for analysis from the Tsunami affected areas.

6.2.1 Kollam Coastal area

From Kollam district, 8 samples and from Alappad Panchayat area 9 samples

were collected for general and microbiological analysis. The samples were drawn from

tube wells and open wells.

Details of location of the wells and the types of wells are given in Table 1.

Table I

Location and type of well and the data on some of the chemical parameters of the water samples

Sl. No. Location EC (micromhos/cm)

Na (mg/L)

Cl (mg/L)

Salinity (ppt)

1. Azheekkal north (TW) 880 26 74 0.37

2. Pookottu Temple (OW) 35200 4550 2182 14

3. Azheekkal old (TW) 1410 88 281 0.59

4. Srayikkad Temple (OW) 82400 7500 1369 29.91

5. Amrithananthamayi matt

(TW) 1570 23 307 0.34

6. Cheriyazheekkal (OW) 902 67 92 0.36

7. Kuttimuttil (OW) 1620 120 197 0.72

8. Pandarathuruthu (OW) 8730 850 1293 3.07

9. Srayikkad (OW-AD) 627 16 12 0.27

10. Azheekkal (TW-BD) 5480 540 593 1.7

11. Azheekkal (TW-AD) 1060 76 96 0.46

12. Kinarmukku (TW) 617 28 8 0.26

13. Azheekkal (TW-BD) 1660 36 259 0.86

14. Azheekkal (TW-AD) 822 26 56 0.34

15. Pandarathuruthu (TW) 1620 104 166 0.71

16. Kuzhithura (TW) 620 16 26 0.24

17. Azheekkal north (TW) 1970 34 219 0.87

TW – tube well, OW – Open well, BD – Before developing, AD – After developing KWA – Kerala Water Authority

These samples were analysed mainly for conductivity, sodium, chloride and

salinity in addition to coliform (Table II and Table III). Conductivity values varied from

617 micromhos/cm to 82400 micromhos/cm. For all the parameters, the highest two

values were observed for the open wells at Srayikkad Temple (Sl.No.4) Pookottu Temple

(Sl. No.2) of Alappad Panchayat, both of which were submerged in the tidal waves. Next

higher value was shown by open well at Pandarathuruthu (Sl. No.8). Among the tube

wells, one at Azheekal (Sl.No.10) showed the highest value for electrical conductivity,

sodium, chloride and salinity.

Four wells were developed after the Tsunami and samples from these wells were

analysed. The well locations are at Srayikkad, Azheekal, Azheekkal Matsya fed

Compound, and Azheekkal North. Water samples were taken before and after

developing from the tube wells in Azheekkal (Sl.No.10 & 11) and Azheekkal Matsya fed

Compound (Sl.No.13 & 14). These samples were compared for electrical conductivity,

sodium, chloride and salinity values. Noticeable reduction was seen in the analysis

values, after development. The difference in result are represented as percentage

reduction (Table II).

Table II % Reduction in Chemical parameters after development

Sl. No. Location EC (redn in %)

Na (redn in %)

Cl (redn in %)

Salinity (redn in %)

10 and 11 Azheekkal I 81 86 84 73

13 and 14 Azheekkal II 50 28 78 60

The values for salinity are plotted in Figure 1. It is verified that the

Salinity comparison

0.37

14

0.59

29.91

0.34 0.36 0.723.07

0.27 1.7 0.46 0.26 0.86 0.34 0.71 0.24 0.870

10

20

30

40

Azheekk

al north

(TW)

Pookottu

Temple

(OW)

Azheekk

al old (

TW)

Srayikk

ad Tem

ple (O

W)

Amrithana

ntham

ayi matt

(TW)

Cheriya

zheekk

al (OW)

Kuttimutti

l (OW)

Pandara

thuruth

u (OW)

Srayikk

ad (OW-AD)

Azheekk

al (TW-BD)

Azheekk

al (TW-AD)

Kinarmukk

u (TW)

Azheekk

al (TW-BD)

Azheekk

al (TW-AD)

Pandara

thuruth

u (TW)

Kuzhithu

ra (TW)

Azheekk

al north

(TW)

Location

salin

ity(p

pt)

Figure 1 – Salinity profile of the well waters at different locations.

open wells of Srayikkad Temple, Pookottu Temple and in the compound of Sri.

Thankarajan, Pandarathuruthu were showing values greater the 1-ppt.

Table III

Analysis data for microbiological parameters

Sl No. Location Type of well

Total coliform (MPN/100 ml)

Faecal coliform

(MPN/100 ml)1. Azheekkal north pump house Tube well 30 17

2. Pookottu Temple, Azheekkal Open well ≥ 1600 ≥ 1600

3. Azheekkal old pump house Tube well 900 140

4. Srayikkad Temple Open well 900 900

5. Amrithananthamayi matt Tube well 4 Nil

6. Cheriyazheekkal Open well 1600 300

7. Kuttimuttil Open well 110 50

8. Pandarathuruthu Open well ≥ 1600 ≥ 1600

As far as bacteriology was concerned samples from 6 open wells and 2 tube wells

were analysed (Table III). (High values for faecal coliform were seen in all the open

wells. Among the tube wells, only one tube well at Amrithananthamayi matt was free of

faecal coleform. The other tube well is contaminated).

6.2.2 Alappuzha Coastal area

From the Alappuzha region, 31 water samples were collected just after the

Tsunami attack. 23 samples (5 open wells and 18 tube wells) were from the departmental

wells in the coastal side. The locations of these wells are given in Table IV.

Table IV

Location and type of water

Sl No. Well No. Location Type of well

1. NHP – 17 Neerkunnam TW

2. NHP – 16 Ambalapuzha TW

3. OW – 5 Purakkad OW

4. NHP – 18 Purakkad TW

5. NHP – 3 Devikulangara TW

6. NHP – 8 Thrikunnapuzha TW

7. NHP – 1 Kayamkulam TW

8. OW – 1 Kayamkulam OW

9. NHP – 7 Nangyarkulangara TW

10. OW – 4 Nangyarkulangara OW

11. NHP – 14 Karuvatta TW

12. NHP – 20 DI Centre, Alappuzha TW

13. NHP – 23 Kattor (Mararikkulam) TW

14. NHP – 25 Thaikkal TW

15. NHP – 27 Pattanakkadu TW

16. NHP – 28 Thuravoor TW

17. OW – 9 Thuravoor OW

18. NHP – 29 Kuthiathode TW

19. NHP – 31 Ezhupunna TW

20. NHP – 30 Eramalloor TW

21. NHP – 22 Aryad South TW

22. OW – 7 Kalavoor OW

23. NHP - 21 Arattuvazhy TW

(TW – Tube well, OW – Open well)

Besides, the 23 samples mentioned above, water samples were also drawn from

wells located outside the departmental area

These samples were analysed mainly for electrical conductivity, sodium, chloride,

salinity and coliform count. Since earlier data is available for some of the wells, a

comparison was done for these wells based on conductance (Table V). Increase in trend

for electrical conductivity values are shown by all the wells, when compared to the

previous results. Though these wells show increasing trend, most of the values were

within acceptable limits.

Table V

A comparative study on the Electrical conductivity values before and after tsunami (micromhos/cm)

Well ID 9/04 12/04 (after Tsunami)

NHP – 16 110 478

OW – 5 203 290

NHP – 8 1490 2080

NHP – 14 133 325

NHP – 23 618 937

NHP – 27 954 1910

NHP – 28 1010 1430

NHP – 30 790 2310

NHP – 22 914 1220

The analytical data for chemical parameters for some of the wells are presented in

Table VII. For sodium, values varied from 54 to 650 mg/L, chloride from 4 mg/L to 200

mg/L, and salinity from 0.05 ppt to 2.47 ppt. NHP 25 showed highest value for salinity.

Increase in total hardness was also noted in some of the wells. The values varied from

233 mg/L to 592 mg/L.

Table VI

Sl. No. Well No

EC (micromhos

/cm)

TH as mg

CaCO3/l

Ca (mg/l

)

Mg (mg/l)

Na (mg/l)

K (mg/l)

TA as mg

CaCO3/l

CO3 (mg/l)

HCO3 (mg/l)

SO4 (mg/l)

Cl (mg/l)

Sal (ppt)

1. NHP-8 2080 258 35 41 250 25 506 0 617 46.0 140 0.93 2. NHP-

23 937 233 83 36 75 5 182 0 222 6 100 0.45

3. NHP-25

5700 592 85 19 650 27 428 41 429 11 25 2.47

4. NHP-27

1910 321 103 15 128 16 312 0 356 5 200 0.07

5. NHP-29

1620 365 83 38 90 15 282 22 178 20 4 0.1

6. NHP-30

2310 277 85 15 120 19 408 0 497 5 38 0.93

7. NHP-22

1220 302 98 13 54 10 278 17 305 62 13 0.49

(EC-Electrical Conductivity, TH-Total Hardness, Ca-Calcium, Na-Sodium, K-Pottassium, TA-Total alkalinity, CO3-Carbonate, HCO3-Bicarbonate, SO4-Sulphate, Cl-Chloride, Sal-Salinity, ppt-parts per thousand)

In addition to the above results, the samples collected from 8 wells outside the

departmental areas also analysed. The location of these wells are given in Table VII.

The analytical fugures for Na, Cl, Salinity, Total Coliform and Faecal Coliform

ate given in Table VIII.

Table VII

Lab No. Location Type of well

Remarks

1382 Azheeka tharayil Gopi, Andhakaranazhi, Cherthala

OW 2 KM from Andhakaranazheekkal junction, op. to sea side along the side of road.

1383 Syrile, Mavelithayyil, Andhakaranazhi, Cherthala

OW 100 m from 1382/04 on the coastal side, sea wall is there.

1384 M.V. Prasad, Mavunkal, Andhakaranazhi, Cherthala Open Pond

1-½ Km away from 1383/04. Domestic and drinking water supply for three wards (about 300 families). Near to the lagoon. Twice developed after the Tsunami attack and added bleaching powder. Most of the trees around this area have sheded leaves except coconut trees.

1385 Chandradasan, Valiya parambil padeettathil, Kallikkad, Arattupuzha Panchayath

OW Used for al purpose, 50 m away from Andhakaranazhi coastal side.

1386 Podiyan, Chirayil Padeetathil, Kallikkadu, Arattupuzha

OW Used for all purpose, 50 m away from 1385/04.

1387 KWA Pump House, Ramcheri

TW 2 Km away from 1386/04

1388 KWA Pump House, Valiyazheekkal

TW Drinking water, used for all purposes

1389 Subramanyam Temple, Valiyazheekkal

OW Seven attacks of Tsunami, 300 m from 1388/04, used for drinking purposes

Table VIII

Lab No. Type of well

EC (micromhos /cm)

Na (mg/l)

Cl (mg/l)

Sal (ppt)

Total coliform (MPN/100 ml)

Faecal coliform (MPN/100 ml)

1382/04 Open well 1240 55 127 0.47 ≥1600 ≥1600

1383 Open well 11800 1100 1442 3.76 500 34

1384 Open well 29500 3000 5024 11.2 500 500

1385 Open well 15500 2400 3642 6.34 1600 900

1386 Open well 16600 2300 2886 6.77 500 500

1387 Tube well 752 41 87 0.43 Nil Nil

1388 Tube well 665 19 17 0.29 1600 1600

1389/04 Open well 1240 67 78 0.56 ≥1600 ≥1600

(MPN/100 ml – maximum probable number per 100 millilitre)

It is seen from the results that all the wells except the one coded 1387, were

contaminated.

After a month, second stages of studies were initiated, both in Kollam and

Alappuzha.

The water samples were analysed for Electrical conductivity, chloride, salinity

and coliform contamination. As salinity intrusion is the most expected outcome of the

impact, the results of salinity studies were interpreted in detail. (fig.2). It can be seen that

most of the wells are showing reduction in salinity values.

Figure 2

Coliform counts of all the above wells are compared and it is seen that most of the

wells show reduction in values (Table IX).

The % reduction in salinity is also included in for the same table.

Table IX

% reduction in microbiological parameters in the second set of samples

Identification TC I

TC II

TC reduction

in %

FC I

FC II

FC read in %

1701 30 0 100 17 0 100

1702 ≥1600 9000 -- ≥1600 9000 --

1703 900 0 100 140 0 100

1704 900 11 99 900 4 100

1705 4 0 100 0 0 Same

1706 1600 1600 0 300 170 43

1707 110 50 55 50 50 0

1708 ≥1600 9000 -- ≥1600 1100 redn

1382 ≥1600 700 redn ≥1600 700 redn

1383 500 13 97 34 8 76

1384 500 1600 increase 500 1600 increase

1385 1600 ≥1600 increase 900 ≥1600 increase

1386 500 ≥1600 increase 500 ≥1600 increase

1387 0 0 same 0 0 same

1388 ≥1600 23 redn ≥1600 23 redn

1389 ≥1600 900 redn ≥1600 70 redn

Here is also it can be seen that most of the wells show reduced number of

coliform as compared to the previous results.

6.3 Conclusion

1. It is believed that the pressure of the wave was transmitted underground through

the coastal aquifer ahead of the surface wave. Reports from Sri Lanka mention

geysers appearing just before the land was flooded. Report from the Maldives

mention wells filled with sand from below. Both events indicate a vertical

upward pressure during the tsunami. More investigations are needed to

understand the effects caused by these differences in pressure.

2. From the information collected by IGRAC (International Ground Resources

Assessment Centre in the Netherlands) the following major impacts on the ground

water resources were identified; salinization of shallow fresh groundwater,

reduction in volume of freshwater lenses, landward shift of freshwater/saltwater

mixing zones, pollution of groundwater by chemicals and other contaminants

mobilized by flooding seawater.

3. From the present studies, it is found, after a month of the occurrence of Tsunami

more than 80% of the wells are showing reduced values in salinity when

compared to the samples collected just after the impact of the tidal waves of

Tsunami.

4. With limited data, it is difficult to conclude that Tsunami had not affected the

ground water permanently.

Chapter VII

TSUNAMI IMPACT ON THE GROUND WATER QUALITY ON ALAPPAD COAST, KOLLAM, KERALA.

V.Sivanandan Achari1*, C. A. Jaison1,

P. M. Alex1, A. Pradeepkumar2, P Seralathan 3 and G. Sreenath4

1School of Environmental Studies, Cochin University of Science and Technology, Cochin– 6820 22

2Department of Geology, University College, Thiruvananthapuram-695 034 3Department of Marine Geology and Geophysics, School of Marine Sciences, Cochin

University of Science and Science and Technology, Cochin- 6820 16. 4Central Ground Water Board, Thiruvananthapuram

7.1 Abstract Alappad in Kollam district is a low-lying coastal belt comprising of a sand bar

with a width about 50-200 m and elevation varying from 0.5to 1.5 m above AMSL. In the

wake of Tsunami, the entire barrier close to the sea was inundated resulting in human and

property loss, badly affecting the agriculture due to seawater seepage and subsequent salt

accumulation by summer evaporation.

Water was sampled from the sampling stations (five Tsunami affected dug wells,

three not affected out of which one was a control well, one deep ground water bore well

and the backwater to the east of the Alappad barrier island called TS canal). The analysis

showed spatial variation in the parameters like: pH 7.1—8.5 (ground water 7.6, TS canal

7.8), conductivity 0.42—20.80 mmho/cm (ground water 0.63, TS canal 65.90) and

chloride 675—5594 mg/l (TS canal/kayal 19,284 mg/l). The monthly variations of these

parameters with respect to control station are evaluated.

7.2 Introduction

Tsunami struck the coastal areas of Kerala on December 26, 2004 at 12.45 pm,

leading to the death of 176 and an estimated loss of property to Rs.1358. 6 Cr. Along the

Kerala coast, three coastal segments were inundated by the Tsunami. The segments are :

Karunagapally (Kollam Dt) to Thottapally (Alappuzha Dt) that extent to a length of 37

km; Anthakaranazhy (Alappuzha Dt) to a distance of 5 km; and Edavanakkadu to Cherai

beach ( Ernakulam Dt) extending to 20 km.

The first two segments of the affected coastal regions: Alappad and Arattupuzha

were completely inundated with seawater. The quality of the ground water sources were

affected due to the sudden influx of seawater brought about by waves with heights

ranging 4 to 7m. The net ground water availability in the Kollam district, of which

Alappad forms a part is 448 MCM/yr. and in Alappuzha District 419 MCM/yr. More

than 30 deep base wells in the entire coastal belt draw ground water from a depth of 70-

200m, to meet the domestic demand.

Apart from the immediate human holocaust, several features of the environmental

degradation became apparent in the following months as the summer advanced leading to

drying up of the soil. Overall, the long term impact of the natural disaster upon the total

health of the coastal environment and sustainability of the region are related to the extent

to which the chemical structure of the soils was changed due to salinity.

The variation in the quality of regional freshwater resources and their natural self-

purification efficiency are crucial determinants to the coastal population of the state.

Natural processes like flushing with monsoon rainfall in tandem with the dewatering of

the saline well water by the users by convetional methods dilute salinity to some extent.

Alkalinity of the intruded water can cause mobilization of Fe, Ca, Al and Phosphates

from the soil.

Figure: 1. Open cut well dug in 1913, which is still used as a fresh water source.

The main objective of this study was the evaluation of the significant water

quality parameters of the ground water of the tsunami affected area, on temporal and

spatial basis. In this study, the variation in the water quality parameters of ground water

of the tsunami-affected Alappad coast was assessed in relation to a representative

sampling site from an unaffected area, one kilometer away.

7.3 Study Area

Alappad coast in Kollam District of Kerala in the southwest coast of India, 9o 6'

N 76o 28' E (Figure 2) where most of the present work is concentrated is the one of the

most seriously affected regions of the Kerala cost with maximum human and economic

loss . The area is a low-lying coastal plane having barrier island coast with a width of

about 50-200 m and elevation varying from 0.5 to 1.5 m above MSL. The entire barrier

close to the sea was inundated resulting in human loss and other property loss, badly

affecting agriculture due to seawater seepage and subsequent salt accumulation by

summer evaporation.

Figure: 2 Study area

7.4 Methodology

Water samples were collected from the shallow dug wells, (depth upto 4m) a

borewell and TS canal to identify the water quality variation since January 2005. The

locations of sampling stations are given in Table 1. Water quality parameters such as pH,

Eh, Conductivity, Alkalinity, Hardness, Chloride, Dissolved Oxygen, Biochemical

Oxygen Demand, Sulphate, Phosphate and Iron were analyzed as per the standard

procedures (APHA, 1998). The results for pH, conductivity, alkalinity, hardness,

chloride, iron and phosphate in all the locations in the month of January 2005, are given

in Table 2. However, the discussions in the paper are mainly concentrated on the

variation of pH conductivity chloride and alkalinity in four selected stations – 2, 4, 6

and 8, during January – April. These are shown in Figure 3, 4, 5 and 6.

Table 1. Water quality Sampling stations (January 2005).

STATION LOCATION* REMARKS

1.Cheriyazheekal Temple (inside)

9o 3’ 049N, 76o 30’ E Well not affected

2.CheriyazheekalTemple (outside)

9o 3’ 049N, 76o 30’ E Well not affected (control)

3.Sankaranarayana Temple 9o 3’ 049N, 76o 30’ E Well not affected

4.Vidyadharan 9o 3’ 049N, 76o 30’ E Dug well affected (flushed)

5. Lalitha 9o3’ 049N, 76o 30’ E Dug well affected (flushed)

6.Kurisady 9o 7’ 078 N, 76o 28 325E Dug well affected (not flushed)

7.Samantha Bhadran 9o 6’ 54N, 76o 28 718E Dug well affected (not flushed)

8.Lakshmi 9o 7’ 078 N, 76o 28 325E Dug well affected (flushed)

9.Borewell 9o 7’ 078 N, 76o 28 325E Ground water

10.Kayal 9o7’ 078 N, 76o 28 325E Back water. * The GPS used was a Raytheon 356E model, with 25m horizontal resolutions and 30 m vertical resolution

7.5 Results and Discussion

The sampling point outside Cheriazheeckal temple (Station 2, Table 1) was

chosen as the control as it was in good shape and not subjected to seawater flooding. The

locals extensively use the well as a reliable fresh water source.

Table 2. Post tsunami water quality parameters of the Alappad coastal region, Kerala, in the month of January 2005

PARAMETERS

STATIONS pH Conductivity

mmho/m Alkalinity mg CaCO3/L

Hardness mg CaCO3/L

Chloride mg/L

Iron

µg/L

Phosphate

µg/L

1 8.2 0.76 132 160 198 409 236

2 7.8 0.57 88 125 87 364 231

3 7.6 0.41 88 95 58 920 217

4 7.1 0.42 202 685 675 936 251

5 7.5 12.74 290 1725 2546 1293 292

6 8.1 1.76 220 300 675 623 413

7 8.5 15.00 211 1300 3953 884 125

8 8.0 20.8 282 2400 5594 913 136

9 7.6 0.63 220 380 N.A. 716 125

10 7.8 65.9 123 7600 19284 1326 N.A. N.A. Not analyzed.

The change in the salinity parameters with respect to time, from January to April

2005 for well 1,3,6,8 are shown in Figure 3,4,5 and 6. Control station 1 in February 2005

showed pH of 8.2, chloride 193mg/L, conductivity 0.8 mmho/cm and alkalinity 140mg

CaCO3/L. By April, the summer showers dilute and to a certain degree flush out some of

the saline intrusion and this fact is reflected in the monitored quality parameters. The

drastic fall in pH from 8.2 to 7.0 explains the rainwater-induced variation immediately

after the first rains of the year. The variation of pH and conductivity are naturally in

phase with chloride variations. Alkalinity rises between January and March in tune with

the rise in salinity, thereafter it shows a declining tendency (Figure.6). In summary, none

of the monitored parameters crosses the maximum permissible values recommended for

the draining (KSPCB, 1997).

The well at sampling Station 3, was inundated by the giant wave of Tsunami. The

water had a rusty color ever since, though it was flushed and cleaned a dozen times.

Originally, the well was a perennial fresh water source. In January and February chloride

concentration remained around 700 mg/L as result of the salinity intrusion. In March

chloride plummeted to 482mg/L due to the impact of summer rains. But in April chloride

showed higher values possibly due to leaching of salts adsorbed to the sand grains.

Conductivity is related to chloride all these months. Alkalinity and pH are low, because

of the regular flushing and cleaning the well. From the characteristic colour of the water

it is evident that after the direct intervention of seawater, there is substantial mobilization

of iron.

Sampling station 6, at Kurisady is one of the oldest wells (Figure 2) on the island

dug in 1913 and is still in remarkably good shape. Tsunami had flooded the well on 26th

December 2004 and nobody has ever since endeavored to restore it to its original use.

Hence, this well registers the temporal variation of a tsunami affected water body, as

anthropogenic intervention is nearly absent. pH is on the alkaline side, because of direct

and serious sea water contamination. pH reaches an all time high of 8.7 in April because

of pronounced eutrophication. In January chloride concentration is high because of the

tsunami induced seawater influx. Later on, chloride steadily falls because of dilution with

ground water as the natural gradient facilitates the diffusion of accumulated salts. But in

April, chloride rises to 482mg/L. Conductivity closely follows chloride concentrations.

But alkalinity shows an erratic pattern.

The well at sampling Station 8 was also inundated by the giant waves. This well,

unlike the sampling points hitherto mentioned, is closer to the tidal canal than to the sea.

Here pH is comparable to that of the seawater in January and February because the water

is predominantly of marine origin. In course of time pH, slightly falls to 7.6 by gradual

dilution with fresh ground water. Increased soil salinity after the tsunami strike resulted

in large scale wilting of perennial vegetation except coconut palm. The most affected

trees are: Arecanut, Jackfruit (Artocarpus heterphilus, Plav), Mango (Mangefera Indica,

Mav), Banyan (Ficus Benghalensis, Aal) and Cashew (Anarcadium Oxidentale,

Kasumav).

Jan Feb Mar Apr6.8

7.0

7.2

7.4

7.6

7.8

8.0

8.2

8.4

8.6

8.8

Figure 3. Monthly variation of pH at stations 1,3,6,8

1, 3 6, 8pH

Month

Jan Feb Mar Apr0

5

10

15

20

25

Figure 4. Monthly variation of conductivity at stations 1,3,6,8

1, 3, 6, 8

Con

duct

ivity

mm

ho/c

m

Month

In March, chloride drastically rises to 6896mg/L because of the intrusion of

leachates flushed down by the first rains of the year. By April, chloride plummets to

1928mg/L because rainwater dilution predominates in the later stages. Alkalinity on the

other hand, does not follow a regular pattern because it has photosynthetic sub-routes

altering bicarbonate levels. The morphology and geographical setting of the island call

for particular concern given the economic vulnerabilities and environmental havocs this

part is prone to. This narrow strip of sand bar running parallel to the main land is

sandwiched by saline waters on either side.

Salt content of the water and other parameters monitored in the subsequent

months of April showed high values indicating that the salt leaching/release behaviour of

the sediments has a direct influence in the water quality of the region. Increased soil

salinity after the Tsunami resulted in large scale wilting of perennial vegetation, except

coconut palm. The trees that were affected are Arecanut, Jack fruit, Mango, Banyan and

Cashew.

Surprisingly, the wilted plants especially Banyan and Mango started to rejuvenate

into new life, with new leaves and buds, indicating that particular plant species are

resilient and outlives salt-stresses.

Jan Feb Mar Apr0

1000

2000

3000

4000

5000

6000

7000

Figure 5. Monthly variation chloride at stations 1,3,6,8

1, 3, 6, 8

Chl

orid

e m

g/ L

Month

7.6 Summary and Conclusion

As stated the width of the island varies from 50m to 200m and the land is more or

less at the sea level. This being the state of affairs a powerful wave can potentially sweep

past the island to the tidal canal on the east. The salt water brought in by the mighty

waves sinks into the soil. With the first rains of the year the adsorbed marine anions leach

down to the fresh water lens a feet down (to the perched aquifer) as is evident from the

data furnished above, resulting in ground water contamination with dissolved solids

(TDS).

When the dry summer month’s advance, salt swings back to the surface soil again

by capillary rise. The trapped salts will vertically oscillate between the perched ground

water lens and the soil horizons for many years before being completely removed. Thus,

the deleterious repercussions of sea wave intrusion are bound to last for a long time to

come, and hence necessitates monitoring of the quality of water periodically. It may be

mentioned that the entire island relies on deep ground water pumped day in and day out

to meet the fresh water needs. Ground water is steadily being pumped out for the last fifty

years. The grave environmental impacts thereof have not been assessed.

Jan Feb Mar Apr

100

150

200

250

300

350

Figure 6. Monthly variation of alkalinity at stations 1,3,6,8

1, 3, 6, 8

Alka

linity

mg

CaC

O3 /

L

Month

When soil becomes saline the riotous vegetation that the island is today

characterized, will grow thin in density and diversity. As the results indicate, already

many of the perennial fresh water wells in the coastal stretch have turned saline by the

invasion of sea waves. The entire island being a porous flatland with heavy mineral black

sand deposits (Alex and Achari, 2005), runoff cannot reach the sea and the tidal canal in

significant amounts. Rainwater sinks and gathers up in pools and puddles. Hence, the

prospects of salinity being washed out back to the ocean are limited. At this rate, the

trapped saline pendulum will take many water years become insignificant even if further

seawater influx is arrested or avoided. Study of seasonal variability of salt mobilization

on the soil with respect to monsoon recharge will be useful for planning long term

remediation and for prevention of the deterioration of the quality of deep aquifers, the

major source of water in the coastal belt.

7.7 Acknowledgements

Department of Science and Technology, Government of India funded this work through

the short-term project, Water Quality Assessment in the Tsunami Affected Coastal Areas

of Kerala (No.SR/S4/Es-135-6.0/2005 dated 03.03.2005).

References

1. Alex PM and Achari VS, Tsunami: options ahead, Kerala Calling, Government of Kerala, 25(4), February, 2005. www.prd.kerala.gov.in, p 17.

2. Alex PM, Salinity Intrusion and Seasonal Water Quality Variations in the Tidal

Canals of Cochin, Ph D thesis, Submitted to Cochin University of Science and Technology, India, June, 2005.

3. Kerala Calling, Government of Kerala, 25(4), February, 2005.

www.prd.kerala.gov.in 4. Kerala Pollution Control Board, Environment effluent and noise standards and

guidelines KSPCB, Trivandrum, India, 1997.

5. Standard Methods for the Examination of Water and Waste water 20th Edition. American Public Health Association, Washington DC: 1998.

6. Tebbut THY. Principles of water quality control, 5th edn. Butterworth and

Heinemann: 1998.

CHAPTER VIII

A PRELIMINARY INVESTIGATION ON THE EFFECTS OF TSUNAMI WAVE TURBULENCE ON THE COASTAL WATER

QUALITY ALONG THE MALABAT COAST.

Venugopal, M.R., Santhosh, K.V., Sreekumar, M.D., Vijesh,A., and Cyril Augustine V. Centre for Water Resources Development and Management,

Kunnamangalam, Calicut, Kerala – 673 571.

8.1 Introduction

The impact of Tsunami resulted in a abnormal rise in the sea level and gave risk

to strong waves along the Malabar Coast of peninsular India mainly on December 26,

2004. The present study, conducted along the Calicut coastal waters, indicates that there

have been some mild but definite changes in the water quality profile of the coastal

region. A comparison of the pre-tsunami and post-tsunami scenarios is made to estimate

the changes occurred, in terms of Suspended matter and Chlorophyll contents of the

coastal water. The changes in the chemical composition of the bottom mud were also

examined. It is also observed that these characteristics have relapsed into their pre-

tsunami state after a few days. The study was carried out based on the OCM sensor data

obtained from Oceansat (IRS P4), supported by field investigations.

8.2 Study Area/ Geographical Location

The present study focuses on a typical coastal stretch ranging from Chaliyam near

the discharge point of Chaliyar River on the south, to Mahe river on the north (Fig.1).

This forms the coastline of the Kozhikode district also.

Kozhikode District

Mahe KOZHIKODE DISTRICT

R. Kuttiyadi

Lakshadweep Sea Quailandy

CALICUT

R. Chaliyar

Fig.1. Calicut coast: Sampling Points (DCPs) established for the study

8.3 Methodology

1. A significant rise in the sea water level was reported along the Calicut region,

during December 26, 2004. IRS P4 (Oceansat) OCM data (P9/R14) were procured for

December 12, 18, 24, 30,, 2004 and January 5, 2005 from National Remote Sensing

Agency, Hyderabad. The datasets were analysed using SEADAS software system

(developed and customized for Lakshadweep Sea by the National Institute of

Oceanography (CSIR), Goa). The results are given as Fig.2, 3, 4 &5.

2. Data Collection Points (DCPs) were established along coastal area on a 1Km X

4Km grid basis (see Fig.1). Mud samples were collected from the sea bottom using a

Van Ween Grab and analysed for their textural characteristics using the Hydrometer

method.

8.4 Results and Discussion

1. The Chlorophyll and Suspended solids along the study area were estimated using

satellite data procured for different days (Fig.2 and Fig.4 respectively).

Fig.2. Estimation of Chlorophyll from OCM data: a typical scenario - analysis carried out by SEADAS software system

CALICUT CALICUT

Beypore

Quailandy

Mahe

The chlorophyll in water indicates the presence of phytoplankton and in turn, the

presence of different types of organic matter that serve as nutrients. Fig.3 and Table1

show the variations in this water quality characteristic with respect to chlorophyll before

and after the incidence of tsunami, derived from OCM data. It is noted that the value of

Chlorophyll content decreased from the pre-tsunami value and then relapsed into the

original state. On December 24, the mean value of Chlorophyll content was 3.5 mgm/m3,

which then dipped into 2.9 mgm/m3 on 30 December 2004. The value increased to 3.0

mgm/m3 by 5 January 2005.

Table 1

Chlorophyll content (mg/m3 at different sampling locations and on different dates

DCPs 12-Dec-04 18-Dec-04 24-Dec-04 30-Dec-04 5-Jan-05

A1A 3.9 4.9 4.9 2.8 3.3

A1B 3.1 3.7 3.7 3.7 2.7

A2A 4.2 3.2 4.6 3.5 3.4

A2B 3.5 3.4 4.1 3.5 3.3

A3A 3.8 3.6 3.4 2.9 4.2

A4A 2.6 4.1 3.7 3.0 2.4

A4B 3.1 3.7 3.7 3.7 2.7

A5A 3.4 3.0 3.7 3.9 3.6

A5B 3.8 3.6 3.4 2.9 4.2

A6B 3.2 2.4 3.8 2.5 2.5

B2B 3.9 3.1 3.7 2.0 2.6

B3A 4.1 3.1 2.5 2.0 3.1

B3B 3.5 3.2 3.0 2.9 2.5

B4A 3.8 3.3 2.9 2.7 3.7

B4B 3.1 3.3 3.4 2.1 2.5

B5B 3.7 3.0 2.7 2.0 2.0

B6A 4.1 3.1 2.5 2.0 3.1

B6B 2.8 2.6 2.7 1.6 2.0

B3A 4.1 3.1 2.5 2.0 3.1

B3B 3.5 3.2 3.0 2.9 2.5

B4A 3.8 3.3 2.9 2.7 3.7

B4B 3.1 3.3 3.4 2.1 2.5

B5B 3.7 3.0 2.7 2.0 2.0

B6A 4.1 3.1 2.5 2.0 3.1

B6B 2.8 2.6 2.7 1.6 2.0

C1A 4.3 2.1 4.8 3.5 4.8

C1B 3.8 2.1 4.3 4.1 2.8

C2A 3.4 2.3 3.9 3.6 3.1

C2B 3.6 1.8 3.7 3.5 3.1

C3A 3.7 2.2 3.2 3.1 4.1

C3B 3.6 2.0 2.8 2.1 1.8

C4A 3.7 2.0 3.3 2.8 2.3

C4B 3.5 1.7 2.5 3.0 2.4

Chlorophyll concentration

0

1

2

3

4

5

6

12-Dec-04 18-Dec-04 24-Dec-04 30-Dec-04 5-Jan-05Date

Chlor

ophy

ll(mg/m

3)

A1A

A1B

A2A

A2B

A3A

A4A

A4B

A5A

A5B

A6B

B2B

B3A

B3B

B4A

B4B

B5B

B6A

B6B

C1A

C1B

C2A

C2B

C3A

C3B

C4A

C4B

Fig.3. Variation of Chlorophyll content during the tsunami period (based on OCM data)

2. Fig.4 shows a typical scenario of Suspended Solids content along the Calicut

coastal stretch, prepared from OCM data. Fig.5 and Table 2 depict the variation during

the tsunami period.

CALICUT

Beypore

Quailandy

Mahe

Fig.4. Estimation of Suspended Solids (mg/m3)M data: analysis carried out by SEADAS software system

Table 2. Suspended Solid content g/m3 at different sampling locations during various dates around the incidence of Tsunami

DCPs 12-Dec-04 18-Dec-04 24-Dec-04 30-Dec-04 5-Jan-05

A1A 5.2 5.7 5.0 5.1 4.2

A1B 4.3 4.2 4.0 5.3 3.8

A2A 5.6 3.7 4.5 4.9 3.8

A2B 4.5 4.0 4.6 5.1 3.7

A3A 5.6 4.1 4.3 5.2 5.1

A3B 5.3 3.9 4.2 4.5 7.0

A4A 3.6 4.8 4.3 3.6 4.0

A4B 4.3 4.2 4.0 5.3 3.8

A5A 4.6 3.6 4.4 4.1 4.0

A5B 5.6 4.1 4.3 5.2 5.1

A6A 5.3 3.9 4.2 4.5 7.0

A6B 4.2 3.1 4.2 5.9 3.2

B1A 5.0 3.6 3.4 3.3 5.0

B2B 4.8 3.2 4.4 2.6 3.6

B3A 5.0 3.4 3.7 2.4 4.0

B3B 4.3 3.6 4.1 2.9 3.4

B4A 5.0 4.0 3.5 4.9 4.9

B4B 4.6 3.8 4.1 4.1 3.7

B5B 4.8 3.4 3.9 2.6 3.2

B6A 5.0 3.4 3.7 2.4 4.0

B6B 3.6 3.2 3.8 2.1 3.0

C1A 5.0 2.4 5.1 3.4 4.5

C1B 4.7 2.4 4.4 3.2 3.2

C2A 4.4 2.5 4.2 3.3 3.5

C2B 4.6 2.1 4.1 3.2 3.2

C3A 4.5 2.5 3.8 3.3 4.3

C3B 4.6 2.7 3.5 2.5 2.6

C4A 4.4 2.3 3.9 3.1 3.0

12-

Chlorophyll concentration

0

1

2

3

4

5

6

Dec-04 18-Dec-04 24-Dec-04 30-Dec-04 5-Jan-05Date

Chlor

ophy

ll(mg/m

3)

A1A

A1B

A2A

A2B

A3A

A4A

A4B

A5A

A5B

A6B

B2B

B3A

B3B

B4A

B4B

B5B

B6A

B6B

C1A

C1B

C2A

C2B

C3A

C3B

C4A

C4B

Fig.5. Variation of Suspended solids during the tsunami period (based on OCM data)

The mean value of suspended solids in samples collected from various DCPs was

4.1 g/m3 on Decmber 24, 2004. However the value showed a reduction to 3.8 g/m3 by 30

December 2004. By January 5, 2005, the value recovered to attain 4.0 g/m3.

2. The bottom sediments were collected from the DCPs and were analysed to

estimate their total organic carbon and organic mater contents. (Table 3 and

Fig.6).

Table 3. Total Organic Matter and Total Organic Carbon in the bottom sediments

Date % TOC % TOM 8.09.04 2.0 3.4

15.09.04 2.8 4.8 20.11.04 2.5 4.2 14.12.04 2.2 3.8 19.01.05 3.4 5.9 2.02.05 2.6 4.6

10.02.05 1.8 3.1 3.03.05 1.5 2.7

% OF TOC AND TOM ALONG CALICUT COAST,2004-05

0

1

2

3

4

5

6

7

8.09.04 15.09.04 20.11.04 14.12.04 19.01.05 2.02.05 10.02.05 3.03.05

% OF TOC% OF TOM

Fig.6. Estimation of Total Organic Matter and Total Organic Carbon in sediments

It was observed that there had been a definite increase in the contents of both

Total Organic matter as well as the Total Organic Carbon in the sediments collected.

However the values showed a trend of relapsing into the earlier values.

8.5 Conclusions

The results clearly indicate that there were mild but definite influences on the

water quality as well as the characteristics of the sediments of the region. The water

quality parameters (chlorophyte and suspended solids) showed definite changes, just after

Tsunami which then slowly recovered over a period of time. This may be due to energetic

mixing of coastal waters and the freshwater flown in from the rivers.

The bottom sediments have also undergone some amount of churning leading to

the release of organic mater associated with the undisturbed bottom mud.

However, further work in relation to other aspects of water quality as well as the

sediments is to be carried out to bring more light into these aspects.

8.6 Acknowledgement

The authors are deeply indebted to Dr E.J.James, Executive Director, CWRDM

for his sustained encouragement for this work. The work was carried out as a part of the

project sponsored by the Kerala State Council for Science, Technology and Environment

Council (KSCSTE), Government of Kerala. The authors also express their deep sense of

gratitude to the council.

References

Kurup,P.G., 1977. Studies on the physical aspects of the mudbanks along the Kerala

coast with Special reference to the Purakkad mudbank. PhD Thesis, Cochin University.

Padmanabhan H, and Pillai.S.E., 1971. An analysis of coastal erosion in the Thumboly—

Thottappally region. KERI, Peechi.

Venugopal,M.R.,et al. 1998. Sediment characteristics of Mudbanks of Kerala Coast,

CUSAT, Cochin.

Cope,Captain 1755. A new history of East India. In; Report of the special committee on

the movement of mudbanks. Cochin Govt. Press 1938.

Dora.Y.L., R. Damodaran and V.Jos-Anto. 1968. Texture of the Narakkal mudbank

sediments. Bull.Frpy. Mst. Biol Oceanogr. Univ. Kerala., 41:1-10.

Gopinathan.C.K., and S.Z. Quasim. 1974.Mudbanks of Kerala, their formation and

characteristics, Indian J.mar. Sci:, 3:105-114.

Joseph.K.J., and V.K.Pillai. 1975. Seasonal and spatial distribution of phytoplankton in

Cochin backwater.Bull.Dept.Mar.Sci.Univ. Cochin, 7 (1):171-108.

Kurup.P.G. 1972, Littoral currents in relation to the mudbank formation along the coast

of Kerala. Ibid., 5(3):158-161.

Nair.P.V.R., Sydney Samuel., K.J. Joseph and V.K. Balachandran, 1968. Primary

production and potential fishery resources in the seas around India. Proc. Symp.Living

Resources,seas around India,Cochin,ICAR,184-298.

Nair P.V.R., K.J. Joseph and V.K. Pillai. 1975. A study on the primary production in the

Vembanad lake. Bull.Dept.Mar. Sci. Univ. Cochin, 7(1):161-170.

Nair.R.R.., P.S.N.Murthy and V.V.R. Varadachari. 1966. Physical and chemical aspects

of muddeposit of Vypeen beach. Internat. Indian Ocean.Exp. News-letter, Symp., 4(2);1-

10

Seshappa.G and R.Jayaraman. 1956. Observations on the composition of bottom muds in

relation to the phosphate cycle in the inshore waters of the Malabar coast

proc.Indian.Acad.Sci. 43:288-301.

Varadachari V.V.R.1966. Some physical aspects of beach erosion of Kerala. IIOE

Newsletter, 4:2-5.

Varadachari.V.V.R and C.S. Murty. 1966. The December 1964 storm in the Arabian Sea

and its effects on the some Kerala beaches.Ibid., 5.

Silas, E G., 1984. Coastal Zone Management. CMFRI, Cochin.

CHAPTER IX

IMPACT OF TSUNAMI ON CROPS, SOIL AND WATER QUALITY ACROSS THE COASTAL BELT OF KERALA - A CASE STUDY

SAM T. KURUMTHOTTICAL, K. VANISRI AND C. K. PEETHAMBARAN *.

Department of Soil Science & Agricultural Chemistry, Director of Research, KAU *

College of Horticulture, KAU P O., Thrissur – 680 656

9.1 Introduction

The impact of Tsunami, which struck the coastal sandy areas of Kerala,

particularly Allapuzha and Kollam Districts on 26 December 2004, was monitored within

a fortnight for the possible impact on soil and water quality in the worst affected parts of

Kerala. In some of the affected areas in Allapuzha district (Andhakaranazhi), many

cultivated and non-cultivated crops were damaged beyond recovery. Among the major

crops that got affected permanently included banana, mango jack etc. Some plants

exhibited typical chloride toxicity symptoms while major tree crops like mango, jack etc

showed tendency to defoliate before turning yellow. In some affected coastal areas,

particularly in Kollam district, where the major crop happened to be coconut, the direct

impact of the killer waves was not immediately evident on coconut trees except that in

majority of the cases the roots remained totally exposed. The physico - chemical changes

brought about by this unusual phenomenon in soil need to be monitored as is likely to

throw real concern on the future of many crops and the natural flora of the affected area

in the coming years

On the backdrop of this concern, soil and water samples were collected from

severely affected areas and were subjected to chemical analysis. Inland water sources

suspected to be contaminated by tidal waves were also monitored for the various quality

parameters on the basis of request from the Department of Agriculture, following receipt

of complaints from farming community regarding the observance of drying of paddy

seedlings in Cheruthana Krishi Bhavan area.

9.2 Materials and methods

The scientific team visited the sites affected by Tsunami on 4th January 2005. The first

site to be visited was at Andhakaranazhi in Alapuzha District.

9.3 General observations noted in the affected areas

The impact of Tsunami on crops was visible in the inland at a distance of around

600 meters from the coastal area. Many trees particularly jack and mango had started

defoliation before any symptoms of yellowing. Banana plants, which were largely

cultivated in that area, in number suffered total loss with marginal scorching and severe

yellowing

Maximum crop diversification was present in the Andhakaranazhi area of

Alapuzha district and for that reason maximum crop damage was noticed in that location.

On the contrary, very little crop diversification was present in the affected coastal areas

of Kollam district particularly in the Alapat, Arattupuzha and Srayikadavu areas having

only one major crop coconut. However coconuts trees of different ages were available in

these areas. It was noted that the age of the palms were more decisive in absorbing the

impact. Tsunami waves had uprooted many young seedlings of 2-3 years. While slightly

older palms were pushed aside, older palms resisted the impact of the waves at their

establishment site. The soils in and around the coconut basins were completely removed

by waves resulting in the complete exposure of many surface roots.

At the time of sampling, the soils were moist and stagnated water could be seen

in isolated soil pockets apart from those present in ponds, wells and ditches. According to

the local people, the affected areas had received good rain, two days prior to sampling.

In the aftermath of Tsunami, in Cheruthana Krishi Bhavan area (Alapuzha

district) there had been reports of drying of paddy seedlings, consequent to the use of the

local canal water. On enquiry, it was noted that the canal is a lead channel from

Thottappally spillway and during Tsunami phenomenon, seawater is believed to have

entered the canal through a damaged shutter, mixed with existing water, spoiling the

irrigation quality of the water.

9.4 Soil samples

Five numbers of soil samples were collected from Alappuzha District, particularly

from the Andhakaranazhi area from Kollam district. At some locations, soil samples

were collected at two different depths to assess the possible variation in soil

characteristics with depth.

The details of the soil samples collected from the Andhakaranazhi area and

Kollam district are presented in Table 1 and 2 respectively.

Table 1. Details of soil samples collected from Andhakaranazhi (Allapuzha District)

Sl. No.

Area Location Depth

(cm)

1 Near Andhakaranazhi area Surface soil around mango tree 0-15

2 Near Andhakaranazhi area Subsurface soil around banana 15-30

3 Andhakaranazhi area Subsurface soil from paddy field 15-30

4 Andhakaranazhi area Surface soil around banana 0-15

5 Andhakaranazhi area Subsurface soil around banana 15-30

Table 2. Details of soil samples collected from Kollam District

Sl. No.

Area Location Depth (cm)

6 Alapad area Surface soil around coconut 0-15

7 Alapad area Subsurface soil around coconut 0-15

8 Tharayilkadavu area Surface soil from open area 0-15

9 Tharayilkadavu area Subsurface soil from open area 15-30

10 Srayikadavu Subsurface soil from coconut garden 15-30

11 Srayikadavu Subsurface soil from coconut garden 15-30

12 Arattupuzha area Surface soil from coconut garden 0-15

13 Cheruthana KB area Surface soil from paddy field 0-15

14 Thrikkunnapuzha Coastal black sandy soil Control

9.5 Water samples

Along with soil samples, representative water samples were also collected from

the then existing water sources in the two districts. The details of water sample collected

are presented in Table 3. While collecting water samples, care was taken to collect

samples from protected wells, open wells, open areas and even from ponds to assess the

impact of tidal waves on the quality of both protected and unprotected water. As a check,

and particularly for comparison, the tap water provided by the Kerala Water Authority

was also taken. For the purpose of investigating the complaints of drying of paddy

seedlings in Cheruthana area, water samples were collected at two depths i.e., one surface

water sample and the other from the bottom of the canal.

Table 3. Details of water samples collected from Allapuzha and Kollam Districts

Sl.No.

Location Source of water Distance from coast in m

W 1 Near Andhakaranazhi Well water 600

W 2 Near Andhakaranazhi Pond water 600

W 3 Andhakaranazhi Well water 200

W 4 Cheruthana KB area Water from the base of the leading canal (Tottappally)

W 5 Cheruthana KB area Water from the upper part of the leading canal

W 6 Tharayilkadavu Water sample from open area 100

W 7 Srayikadavu Water sample from well 250

W 8 Andhakaranazhi KWA tap water Control

Standard procedures were adopted for the analysis of different parameters of soil

and water samples collected for the study.

9.6 Results and discussion

In the soil samples collected from Andhakaranazhi area. The entire soil texture

appeared to be sandy in nature, clearly indicating the influence of the coast. This sandy

nature must have permitted heavy percolation of seawater in the soil during the short

course of its impact, loading the soil and ground water with many of the dissolved salts

present in seawater.

As maximum crop diversification was available in Andhakaranazhi area, the

impact of the unique tidal waves on the growth and status of different plants could be

noted all along the affected inland area particularly up to a distance of 600m. The

response of many plants to this unique phenomenon was different. Many plants turned

yellow, defoliated and later dried up completely, while many remained unaffected.

Among the major crops that got affected in Andhakaranazhi, banana crop recorded

maximum damage. Initial yellowing, typical marginal scorching of the yellowed leaf,

breaking of leaf axil and development of crakes in psedostem was common. Intensity of

scorching symptoms was more apparent in the lower leaves than upper leaves in banana.

In some acute cases of crop damage, shriveling of psedostem and rotting of rhizomes

were noticed. When affected banana psedostem was split open, inner browning in the

vascular area was also noted. It was seen that none of the affected plants recovered from

the damage. The response of different banana plants in exhibiting the intensity of

symptoms were quite varying, probably on account of its varietal variations. From among

a group of severely affected banana plants in the same location, the presence of green

colour on psedostem and presence of green terminal leaf was noticeable in some plants.

On extradition of such plants from soil, it was seen that the entire roots have been

damaged. No inner browning in the vascular area was noted in such cases. This

observation of green colour on psedostem and the presence of terminal green leaf is to be

construed as the tendency of the banana plants to survive adverse conditions under some

temporary relief in the salt concentration in rhizosphere, due to the rains received after

the initial impact. Higher concentration of salts in the rhizosphere must have resulted in

total root damage. While assessing the impact of Tsunami on major tree crops in the area,

it was noted that mango, jack and arecanut were worst hit. Mango trees responded to this

phenomenon through immediate defoliation, without exhibiting any visual symptom of

yellowing. In the case of coconut though no specific symptoms of yellowing or other

visual toxicity were noticed, there was considerable button shedding. Some plants like

guava exhibited typical chloride toxicity symptoms, indicating clear brown marginal

scorching on healthy leaves and later the tendency to defoliate. Some of the annual crops

like chillies and pulses were completely damaged by the impact of Tsunami. Small

shrubs reacted more quickly than bigger ones due to salinity. However many plants in

that area survived the Tsunami effect even without showing any visual symptoms in their

growth characteristics. This kind of survival may probably be due to the genetic

adaptability of such plants to saline situations. The abundant occurrence of such

unaffected plants in and along the coastal areas is an indication of their survival habitat.

In this context, it is worth noting that all the affected plants were of the cultivated type,

having difficulty to survive under adverse conditions like the intrusion of seawater. The

impact of the tidal waves at the same spots in Andhakaranazhi area was again assessed

on 15.02.2005, (nearly after two months of occurrence) by physically verifying the crop

situation. It was then noted that some plants, which initially succumbed to the tidal waves

had started recovering. Accordingly, it was possible to classify the major flora in

Andhakaranazhi area, into three major groups, viz., completely susceptible, tolerant and

recovered crops. This is presented in table 4. The ability of some relatively hardy plants

to survive the adverse soil condition and re-establish itself after a month must have been

due to reduction in the salt concentration in the rhizosphere brought about by a few good

rains received in that area.

Table 4. Details of crops, which responded differently to Tsunami tides in Andhakaranazhi area

Sl. No. Completely susceptible Tolerant Crops which recovered

1 Arecanut Thespesia populnea Tamarind

2 Banana Acacia Subabul grass

3 Mango Eliocaris (weed) Nellipuli

4 Jack Cerbera odollam Lawsonia alba

5 Guava Pandanus spp Terminalia catappa

6 Bamboo

7 Ocimum spp

8 Vetiveria spp

9 Hibiscus

10 Annona

11 Croton

12 Ixora

9.7 Assessment of chemical changes in soil samples

The different soil samples collected from the affected areas of Alapuzha and

Kollam districts were subjected to chemical analysis and the results were compared with

control sample taken from an unaffected coastal area viz. Thrikkunnapuzha.

Table 5 depicts the texture, pH, EC and the computed TDS (Total Dissolved

Salts) of the various soil samples collected for the study. All soil samples collected from

Tsunami hit coastal area were observed to be sandy in nature. The soil sample collected

from the Cheruthana Krishi Bhavan area, particularly from a paddy field where drying of

seedlings were noticed (Sample 13), exhibited clayey texture. Except Sample 13 and

control (Sample 14), all the soils registered an alkaline soil reaction probably due to the

influence of the intruded seawater. In almost all the soil samples the conductivity was

observed to be normal except in sample 8 (collected from Tharayilkadavu area of Kollam

district) where EC crossed the critical limit of 4 dS m-1. The reason for the observed low

EC values might have been due to the dilution effect on account of the rains received two

days prior to the sampling. TDS values did not show any abnormal indication of

dissolved salts in soil except in sample 8.

Table 5. Soil reaction and electrolytic conductivity of the different Tsunami hit

samples

Sample No. Texture pH Rating EC (dSm-1) Rating TDS (ppm)

1 Sandy 8.5 Alkaline 1.72 Normal 1100.8

2 Sandy 7.8 Alkaline 1.49 Normal 953.6

3 Sandy 7.4 Alkaline 1.91 Normal 1222.4

4 Sandy 7.8 Alkaline 0.72 Normal 460.8

5 Sandy 7.2 Alkaline 1.61 Normal 1030.4

6 Sandy 8.1 Alkaline 0.29 Normal 185.6

7 Sandy 8.0 Alkaline 0.46 Normal 294.4

8 Sandy 7.7 Alkaline 4.99 High 3193.6

9 Sandy 7.8 Alkaline 3.76 Normal 2406.4

10 Sandy 8.2 Alkaline 0.16 Normal 102.4

11 Sandy 8.5 Alkaline 0.65 Normal 416.0

12 Sandy 7.8 Alkaline 0.86 Normal 550.4

13 Clayey 5.5 Acidic 0.78 Normal 499.2

14 Sandy 5.8 Acidic 0.60 Normal 387.2

* NS – Non-significant

Concentration of basic cations Viz., Na, Ca, & Mg ultimately influences the SAR

values (Sodium Adsorption Ratio) in soil. The SAR values obtained from the soil extracts

(1:5 ratio) are presented in Table 6. The concentrations of calcium, magnesium and

sodium in the soil extracts appeared to be significant, when compared against control.

Between different sampled locations, there was considerable variations in the

concentrations of these basic cations. This might be due to several reasons, the most

probable one being variation in the intensity of rains received in that area after the

Tsunami and the consequent leaching or dilution of salts. However, due to sufficient

amounts of calcium and magnesium in the soil extract, the ill effects of a fairly high level

of sodium, which otherwise might have exerted secondary effects on plant growth

through adverse structural modifications in soil got attenuated. This was very much

evident while assessing SAR values. In all the case studied, the sodium hazard in the soil

is likely to be low to medium. However, in one location Tharayilkadavu area of Kollam

district. (Sample 8), the SAR values indicated high hazard, due to comparatively high

content of sodium over that of Calcium and Magnesium. However, the extract from the

sub surface sample of the same soil, recorded medium SAR value. Rest of the soil sample

extracts indicated low and safe ranges of SAR.

Table 6. Concentration of basic cations and Sodium Adsorption Ratio of the soil

Sample No. Calcium

(me L-1)

Magnesium

(me L-1)

Sodium

(me L-1)

SAR of soil

extract (1:5) Rating

1 49.5 29.16 44.35 7.07 Low

2 54.0 26.66 17.00 2.67 Low

3 51.5 51.66 65.76 1.27 Low

4 38.5 23.33 28.91 0.93 Low

5 45.0 37.50 29.34 4.56 Low

6 14.5 18.33 5.43 1.34 Low

7 13.0 19.16 8.30 2.07 Low

8 44.0 12.50 133.78 25.19 High

9 30.5 35.00 88.17 15.41 Medium

10 11.0 15.00 3.35 0.93 Low

11 54.0 26.66 13.87 2.18 Low

12 18.5 18.33 4.65 1.08 Low

13 39.5 27.50 24.35 4.21 Low

14 18.5 16.50 7.60 1.80 Low

The sodium content and cation exchange capacity of the soil relating to the

various samples collected from Tsunami hit areas are given in Table 7. The sodium

content of the soil was fractionated into two forms viz., water soluble and exchangeable

sodium. The results indicated that the water-soluble sodium content exceeded

exchangeable sodium in all cases. This perhaps might be due to the low CEC associated

with the sandy soils, where soil colloids fail to adsorb greater portions of this cation.

While assessing the CEC of the different soil samples, it could be seen from the table that

soil samples 1 and 2 recorded relatively high content of CEC (39.6 and 38.6 meq/100g

respectively) over the rest of the samples. It may be recalled that these samples though

sandy in nature , represent the rhizosphere of the affected mango and banana plants

where sufficient organic matter should normally be expected, which in all probability

might have contributed to high CEC in the soil.

Table 7. Sodium content and Cation Exchange Capacity of the different Tsunami hit

samples

SAMPLE No. Water sol.

Na (ppm)

Exch.Na

(ppm)

Total Na

(ppm)

CEC

(me/100g) Rating

1 940 80 1020.0 39.6 High

2 320 71 391.0 38.6 High

3 1350 162.5 1512.5 5.4 Very low

4 600 65 665.0 4.6 Very low

5 480 195 675.0 1.8 Very low

6 80 45 125.0 2.5 Very low

7 156 35 191.0 2.8 Very low

8 3050 27 3077.0 2.5 Very low

9 2000 28 2028.0 2.6 Very low

10 56 21 77.0 2.5 Very low

11 270 49 319.0 3.0 Very low

12 80 27 107.0 2.6 Very low

13 410 150 560.0 3.2 Very low

14 122 40 162.0 2.5 Very low

The concentrations of chloride and exchangeable sodium percentage of different

Tsunami hit soil samples is presented in the Table 8. It is reported that concentration of

chloride in solutions more than 20 mM cause toxicity in sensitive plants, while tolerant

species can accommodate 4-5 times higher values without affecting the growth. The

chloride content of the soil samples ranged between 5.99 and 29.96 me L-1. However, 50

per cent of the soil samples had chloride content in the toxic range and the remaining 50

per cent samples including control indicated safe limits. Majority of the problems

observed in plants are due chloride toxicity. Due to heavy absorption of salts from the

rhizosphere, accumulation of these ions occur in leaves and they result in the browning

and scorching of leaf top and margins. This typical observation in the plant foliage was

very conspicuous in the affected area, particularly in Andhakaranazhi. The browning was

more conspicuous in banana, guava and in many of the annuals which dried up within

days. It is well known that the presence of excessive concentration of one ion is also

likely to interfere with absorption of another ion thus hampering the nutrition of plants.

Further, the presence of excessive salts in the soil is again likely to enhance the osmotic

potential of the soil solution, further preventing the plants from absorption of nutrients or

even water. All these problems either individually or collectively must have contributed

to the susceptible flora of the region leading to either defoliation or total drying of plants.

Defoliation in mango must have been due to the inability of the plant to absorb water

from the soil following high osmotic pressure in the rhizosphere soil solution. According

to Schulte (1999) true toxicity results from plant accumulation of excess chloride,

particularly where soil water contains high concentration of dissolved substances

preventing the plants from obtaining enough water, thereby causing the plants to wilt.

The response of the defoliated mango trees and jack trees to rejuvenation in the coming

days is yet to be assessed. The Exchangeable Sodium Percentage (ESP) which was

computed from total sodium content and cation exchange capacity was found to be high

(> 15) in two samples Viz. Sample 5 (a sub soil sample near Banana plant in

Andhakaranazhi area) and Sample 13 (the paddy soil from Cheruthana Krishi Bhavan

area.). The presence of high exchangeable sodium in the rhizosphere of banana might

have contributed to the root damage, leading to the death of plants. In all possibility, the

presence of high sodium content in the above two samples must have been contributed by

the seawater. The presence of low chloride and sodium content in the control compared

to other samples clearly points to the seawater as the contaminant source for sodium

chloride in soils. Rain or other local factors might have resulted in the dilution of salts

and the observed variations seen between different sites. Presence of chloride of 5.99me

L-1 in (Sample 13) observed in a paddy soil, may be due to irrigation with contaminated

saline water. The presence of very high content of ESP in the sample again indicates the

role of seawater in enhancing the sodium content. High mobility of chloride ions in soil

must have been responsible for the observed low content of chloride in the surface soil.

Since majority of the soil samples recorded fairly high content of chloride and in view of

the well established fact that chloride toxicity to plant tissues is imminent in such

conditions, all kinds of the manifestations seen on different crops in that locality must

have been due to the direct impact of chloride.

Table 8. Concentration of chloride and Exchangeable Sodium Percentage (ESP) of the

different Tsunami hit samples

Sample No. Chloride

(me L-1) Rating ESP (%) Rating

1 19.97 Toxic 0.87 Low

2 19.92 Toxic 0.79 Low

3 21.97 Toxic 13.07 Medium

4 13.98 Safe 6.13 Medium

5 19.98 Toxic 47.05 High

6 19.98 Toxic 8.86 Medium

7 13.98 Safe 5.42 Medium

8 29.96 Toxic 4.87 Medium

9 23.97 Toxic 4.65 Medium

10 11.98 Safe 3.79 Medium

11 12.98 Safe 7.1 Medium

12 11.98 Safe 4.5 Medium

13 5.99 Safe 20.37 High

14 8.97 Safe 0.40 Low

9.8 Assessment of water quality in the collected water samples

The pH and electrolytic conductivity of the different inland water samples are given in

Table 9.

Table 9. pH and electrolytic conductivity of the different inland water samples

Sample No. pH Rating EC (dSm-1) Rating TDS (ppm)

1 6.9 Towards neutral 3.81 Normal 2438.4

2 6.8 Towards neutral 39.1 Very High 25024.0

3 7.3 Alkaline 18.84 Very High 12057.6

4 7.2 Alkaline 24.1 Very High 15424.0

5 6.9 Towards neutral 2.25 Normal 1440.0

6 8.2 Alkaline 46.2 Very High 29568.0

7 7.8 Alkaline 57.1 Very High 36544.0

8 6.7 Towards neutral 2.40 Normal 1536.0

The water samples exhibited near neutral to alkaline reaction. Most of the water

samples have very high conductivity and TDS (calculated value) indicating their

unsuitability to either human consumption or irrigation purpose. For the purpose of

comparison, tap water provided at Andhakaranazhi by Kerala Water Authority was taken

as the control. Among the different water samples studied, the KWA tap water indicated

safe ranges for both pH and EC values. In the study it was noted that there had been

considerable variation in the water quality between the upper and lower column of water

in the canal in the Cheruthana area where contamination with seawater had been

suspected. The analysis of the two water sample collected from the surface and bottom of

the canal leading to Cheruthana area from Thottappally (sample 4 &5) indicated that tidal

waves of Tsunami might have made an entry through a damaged shutter. Not

recognizing the effect of this intrusion of saline water in the canal, the water has been

lavishly pumped from the canal into rice fields for some time and later on noticing some

drying problem, the farmers declined to use any water from the canal. During the

investigation, the team collected water samples (from the lower part of the canal (sample

4) and from surface (sample 5)). At the time of collection, the canal water remained

more or less stagnant with no inward or outward flow. Results indicated relatively high

pH values (7.2) and high EC (24.1 dSm-1) for the water samples collected from the

bottom as against the relatively lower value for the surface sample where the

corresponding pH and EC values were 6.9 and 2.25 dSm-1 respectively.

The observed high EC values in water taken from the bottom, (sample 4) is a clear

indication of the abundant quantities of soluble salts in the channel bed. With the entry of

saline water in the channel where the flow of the fresh water is not so great, the salt water

prefers to occupy the lower part of the channels on account of its higher density than

fresh water. A similar observation had been recorded by Parker, (1969). Pumping of

such canal water into the fields inevitably loads relatively denser sea water into the fields

than surface water as the foot valve occupy the basal portion of the canal

Except three water samples, the conductivity was observed to be very high (> 4

dS m-1) in all samples. The direct intrusion of tidal waves into these water bodies might

have been responsible for an increase in sodium and soluble salt content and a subsequent

increase in pH of the water samples. The higher pH observed in samples might have been

due to the impact of hydrolysis of sodium.

The concentrations of calcium, magnesium, sodium and Sodium Adsorption Ratio are

presented in the Table 9.

Table 9. Concentration of calcium, magnesium, sodium along with SAR of the different

inland water samples

Sample No. Calcium

(me L-1)

Magnesium

(me L-1)

Sodium

(me L-1) SAR Rating

1 38.5 20.0 25.22 4.66 Low

2 190.0 266.6 434.78 28.77 Very high

3 133.0 94.16 173.91 16.33 Medium

4 82.5 170.8 260.86 23.19 High

5 6.5 25.0 13.48 3.39 Low

6 200.0 296.6 521.74 33.13 Very high

7 167.0 508.3 782.61 42.59 Very high

8 15.0 20.5 18.48 4.27 Low

Calcium content in the different samples was significantly different. The

maximum calcium content of 200 me L-1 was observed in the water sample collected

from Tharayilkadavu area (100m away from coastal area) and the minimum content of

6.5 me L-1 was noticed in the surface water sample collected from leading canal in the

Cheruthana Krishi Bhavan area. The calcium, magnesium and sodium content observed

between the surface and bottom layer in the canal were quite different indicating the

influence of seawater in modifying the salt content even within a water column. The

highest content of magnesium (508.3 me L-1) was present in a well water sample taken at

a distance of 250m away from coastal area (Srayikadavu area) indicating that sea water

has entered the well either during tidal ingression or due to ground water contamination.

The lowest content of 20 me L-1 of magnesium was noted in a protected well water

collected near Andhakaranazhi area of Alapuzha district (600 m away from coastal area).

Incidentally this is comparable with the control values. It is also clear that greater the

distance of the sampling spot from the seacoast, lesser could be the impact in terms of

contamination. The lowest sodium content among the water samples analysed was noted

in the surface water sample in the canal in Cheruthana Krishi Bhavan area (13.48 meL-1)

while the highest content of 782.61 meL-1 in the well water, which is 250m away from

coastal area (Srayikadavu). Among all the water samples, those samples collected from

open areas were found to possess very high Sodium Adsorption Ratio indicating the

possible alkali hazard from such soils once used for irrigation. The SAR in the rest of the

water samples ranged from low to medium. The lowest SAR was noted in the control

sample followed by a well water identified at 600 m away from coastal tract of

Andhakaranazhi area. In general, it is noted that protected well-retained better quality

than open wells or water bodies. In the absence of sub surface or bottom layer water

samples form these water bodies, the analytical picture of surface water samples may

again remain deceptive in assuring the quality.

Table 10 depicts the concentration of carbonate, bicarbonate and chloride of the different

inland water sample

Table 10. Concentration of carbonate, bicarbonate and chloride of the different

inland water samples

Sample No. Carbonate

(me L-1)

Bicarbonate

(me L-1)

Chloride

(me L-1)

1 0.9 0.90 0.64

2 0 4.04 9.07

3 1.8 0.44 3.92

4 0 1.79 5.18

5 0 1.34 0.36

6 0 3.15 10.42

7 0 2.25 10.52

8 2.7 1.34 0.41

Mean 0.38 1.98 5.73

SE 0.28 0.51 1.78

t value 2.8 1.24 2.98

The carbonate concentration of water samples collected from pond, leading canal

(Tottappally), from an open area 100m away from coastal area and from well 250m away

from coastal area were found to be practically nil, while samples1, 3 and control

registered 0.9, 1.8 and 2.7me L-1 of carbonate respectively. However, the bicarbonate

content of the water samples collected from various locations ranged from 0.44 (Well

water at Andhakaranazhi) to 4.04 meL-1 (Pond water near Andhakaranazhi).

Concentration of chloride ions ranged from 0.36 to 10.52 meL-1 and at these

concentrations, the water samples are totally unfit for agricultural purpose and once it is

used, it is sure to create phyto- toxicity in plants. Excessive amount of free available

chloride (greater than 0.05 mg per litre) will cause leaf-tip burn and damage to some

sensitive crops Mughal (2005). In the backdrop of these analytical values it is once again

reiterated that crop damage in the coastal area, particularly in Andhakaranazhi has

occurred due to chloride toxicity and not due to any other reason.

References:

Schulte, E.E. 1999. Soil and Applied Chlorine. University of Wisconsin, Madison.

Available: http://cecommerce.uwex.edu/pdfs/A3556.PDF [21 February, 2005]

Marschner, H. 1986. Mineral Nutrition of Higher Plants. Academic Press, London,

674p.

Parker, G.G. 1969. The encroachment of salt water into fresh. Water (ed. Stefferud, A.).

Oxford & IBH Publishing Co, Calcutta, pp. 615-635

Mughal, F.H. 2005, Jan. 17. Unspecified standards for treating wastewater for irrigation. Dawn. Available: http://DAWN.com

CHAPTER X

IMPACT OF TSUNAMI ON COASTAL AGRO-ECOSYSTEMS OF INDIA AND STRATEGIES FOR RESTORATION

Dr. Rajagopal Central Plantation Crops Research Institute, Kasaragod

10.1 Introduction

Tsunami waves hit Indian coast on 26th December 2004 wreaking havoc across

the southern coastline. The waves are triggered by seismic disturbances on the ocean

floor. The tsunami waves were caused by a massive earthquake on the Indian Ocean near

Sumatra in Indonesia. The result is a deep wave, stretching from the sea’s surface to the

floor that travels horizontally at speeds of up to 500 miles per hour and reaches heights of

15 to 30m and weigh millions of tones. Though the bottom of the wave is slowed down

by the sharp elevation of the ocean floor near the coast, its top part keeps moving at the

original speed. As a result, vast quality of water piles up and finally crashes over the

shore with amazing force, thus causing massive destruction. The first sign of an

approaching Tsunami is the sea tide receding from the shore, which leaves a large part of

the sea floor exposed. The ocean water then flows towards the shore faster than before,

resulting in high waves. This phenomenon is repeated several times before the Tsunami

itself hits the land. Fisher folk in Indian coast were virtually caught unaware in the ocean

fury as huge waves pounded. The Tsunami thickly hit the populated coastal areas of

Tamil Nadu, Pondicherry, Kerala and Andaman and Nicobar islands of India, thickly

populated fishing hamlets, resulting in death and destruction.

In Tamil Nadu, Chennai, Thiruvallur, Kancheepuram, Cuddalore, Nagapattanam,

Tiruvarur, Thanjavur, Thoothukidi, Ramanathapuram, Tirunelveli and Kanniyakumari

are the districts most affected, leading to loss of life of 8010 dead and rendered among 10

lakh people homeless. The giant waves have also affected the Pondicherry and Karaikal

of the Union Territory of Pondicherry causing severe damage. In Kerala, Kollam,

Alappuzha and Eranakulam are the major districts affected causing death of 173 human

lives.

10.2 Impact of Tsunami in Kerala

10.2.1 Soil and Water :

Tsunami affected areas, in general, are a narrow strip of land between sea and

back water. Soil along the affected areas of Kerala coast is littoral sand. This led to

severe erosion of topsoil to a depth of about 30cm exposing roots of coconut palms in

some areas, in certain other areas.

Exposed roots were showing symptoms of drying. Soil was not eroded in certain

places and ipomea biloba was present in such areas. It was informed that water from sea

was deep brown in colour with foul smell and stagnated for two hours to three days.

Certain areas, the Tsunami sea water got mixed up with back water and intruded into the

adjoining areas. Water collected from inundated area (both from open and bore well)

showed very high salinity (up to 0.62 ppt) and electrical conductivity (upto 1247

microseimens/cm). The pH ranged from 6.55 to 8.82.

10.2.2 Plants and Animals

Intrusion of seawater to a distance of about 500m caused severe damage to plants

and animals. Arecanut (Areca catechu), Mango (Mangifera indica), Jack (Artocarpus

heterophyllus), Breadfruit (Artocarpus insisa), Ficus (Ficus sp.), Anjili (Artocarpus

hirsute), Tamarind (Tamarindus India), banan and papaya were completely dried.

Coconut palms withstood the impact of gushing water and high salinity to survive the

natural calamity. However, yellowing of outer whorls or leaves in older palms, button

shedding, bunch buckling and uprooting of seedlings were observed in some places.

Plants like Poovarasu (Tespesia populnea), Punna (Caalophyllum inophyllum),

Pongamia glabra, wild badam (Indian almond) (Terminalia catappa), Casuarina

equisitifolia etc. were tolerant to tsunami water and survived. Most of the poultry, duck

and cows perished.

10.2.3 Socio-economic aspects

In Kollam and Alappuzha districts, arecanut is one among the crops, which is

severely affected due to salinity, causing an average damage of Rs.100/palm/year. The

Development Departments need to take corrective measures through appropriate schemes

for saving the affected palms and to compensate the loss incurred to the farmers.

Similarly, the State Department of Animal Husbandary may implement proper schemes

for restoring the livestock based activities in the affected villages. Almost all the fisher

folk lost their fishing boats, nets and other gadgets for fishing etc. putting them into great

difficulties.

10.3 Strategies for management in Kerala

10.3.1 Short term :

Restoration of topsoil – exposed coconut basin may be filled with the soil from

surrounding areas and planting of ipomea as soil cover.

Application of soil amendments –

Improvement of drainage –

Soil moisture conservation – mulching with coconut leaf, coir pith etc.

Irrigating with fresh water/saline water.

Planting of arecanut, banana and other tuber crops

10.3.2 Long term :

Evolving a cropping system – identification of salt tolerant cultivars plantation

Establishment of green belts – casuarinas, mangroves, pandanus, Thespeisia

populnea and Pongamia glabra on the coast

Augmenting animal husbandary and fodder grasses

Enhancing small scale industries – coir, marine products,

Promoting back water eco-tourism

CHAPTER XI

ECOLOGICAL REHABILITATION OF TSUNAMI- AFFECTED AREAS OF KOLLAM AND ALAPPUZHA DISTRICTS IN KERALA

P.K.K. Nair, P.K. Shaji And R.S. Biju Priyadarsan Environmental Resources Research Centre, P.B. 1230, P.O. Peroorkada, Thiruvananthapuram-695 005.

11.1 Introduction Nature has certain in-built attributes in protecting habitats and the life associated

with it. The coastal system is characterized by the sea subtended by the beach and the

landmass. The interzone between the habitational zone and the sea has characteristic salt

tolerant vegetation known as mangroves, which is restricted to the estuarine areas. Other

areas of interzone possess scanty vegetation, comprising of strand sand and strand rock.

This shows the need for having a totality of information on the vegetational pattern of the

entire coast in evolving appropriate rehabilitation measures to contain the fury of the sea.

Wit this idea in mind a team of researchers from ERRC visited the tsunami-hit areas of

Kollam and Alappuzha districts and prepared notes on the ecological revenge caused to

the area, the vegetation and individual plant elements that survived the tsunami disaster

and also impacts on crops and other plants with extended distribution to the wetland

system outside the disaster zone. The findings and proposals generated during the visit

are summarized below.

The coastal areas of Kerala that are the worst affected in the recent devastating

tsunami on 26 December 2004, are located in Kollam (Cheriazheekkal, Alappad and

Srayikkad in Karunagappally Taluk) and Alappuzha (Azheekkal, Arattupuzha in

Karthikappally Taluk) districts. The affected areas from a narrow strip of land (width

ranging from 75 to 200 m) between sea (Arabian) and backwater (Kayamkulam Kayal

and associated network of water channels) and remain dissected by the estuary. These

densely populated land strips, lying on both sides of the estuary, show remnants of

mangroves with isolated thickets of Excoecaria agallocha, Avicennia officinalis,

Acanthus ilicifolius and Achrostichium aureum. This clearly indicates that these areas

once had an intact cover of mangroves, which has been cleared for development of

habitation. There are also naturally occurring trees, like Thespesia populnea, Hibiscus

tiliaceus, Pandanus, tall grasses with tufted root systems like Saccharum spontaneum

and Phragmites carca apart from planted trees like Garcinia gummi-gutta (Malabar

gamboge), Mangifera Indica (Mango) and Artocarpus heterophyllus (Jackfruit tree)

towards interior areas from the coastline, providing timber, food and medicine. Another

tree element of relevance is Casuarina equisettifolia (a tree introduced from Australia),

which is cultivated at places along the coast.

A visit to the tsunami-affected locations gave a picture of the devastation caused

by the disaster and the efforts being done for rehabilitating the people, rebuilding the

houses and regenerating the ecosystem. The area is coconut dominated with few other

crops, of which the plantain has been significant, a majority of which has been destroyed

and dried out. The local people have reported the fruit trees like mango and jack tree

have dried out and which have been cut down fuel purposes of late. Otherwise the area

has less vegetative cover but for patches of Pandanus odoratissimus, few mangrove

patches and some sand binding creepers like Ipomoea pes-capre, and Spinifex littoreus,

and few types of sedges towards the backwater end. As mentioned earlier, there are a

few economically useful minor plants, like Calophyllum inophyllum, Premna latifolia,

Terminalia cattapa, Glyricidia sepium, Erythrina stricta etc. At one part of the land strip

(at Srayikkad), a small belt of Casuarina tree has been raised behind the artificial sea

wall.

The requirements for ecological rehabilitation of the coast involve research and

development relating to generation of database on vegetational composition, assessment

of impacts and formulation of experimental greenbelt model within the framework of the

existing vegetation, which could not only act as a buffer to tsunami like ravages of the

sea but also as a provider of materials for livelihood including fuel wood, food fodder and

other products of economic value. The technical proposals (approach) for ecological

rehabilitation could be resolved as follows.

1. A grid-wise taxonomic/vegetation survey of the coastal belt of Kollam and

Alappuzha districts, with emphasis to tsunami-affected areas. Base map of the

coastal belt can be prepared using topographic sheets (Survey of India), with the

entire coastal belt of Kollam and Alappuzha districts covered in uniform grids

(with a number assigned to each grid for convenience). The survey and

documentation of coastal vegetation including mangrove stands/patches, strand

sand and strand rock system can be done in the study area by locating the above

grids in the field using a Geographical Positioning System (GPS). Location of

important components, including RET category species (IUCN categories of rare,

endangered and threatened species), can also be recorded during the survey.

2. Collection of local information on the ravages caused by the disaster by means

of interaction with the people.

3. Assessment of changes in vegetation pattern and composition in the tsunami-

affected locations (impacted zone) can be made by means of comparison with the

similar areas in the vicinity which are not affected by the disaster (control zone).

Here the tolerant and sensitive species can be categorized based on the injury

symptoms manifested by the species, with respect to the environment stress.

4. Qualitative/quantitative assessment of the physiochemical characteristics of soil

and water (concentration of nitrogen, iron potassium and phosphorus; salinity,

pH, and dissolved oxygen; etc.), which have a bearing on plant/crop

establishment. Mycorrhizal association of important agroforestry crops can also

be studied.

5. Collection of information on the economic/traditional uses of the plant

resources (including medicinal uses) and other data on agro-technology

(propagation methods) in specially designed fact sheets.

6. Preparation of spatial distribution maps for important component species of

coastal vegetation (species of economic and ecological interests; plants of rare

and endangered categories) and systems (such as mangrove stands and Pandanus

thickets). For recording the locations of such stands and species, a GPS can be

used. For preparation of spatial distribution maps, suitable software

(Surfer/Mapinfo) can be used.

7. Identification of appropriate species for greenbelt development in the coastal

areas.

8. Mapping of potential areas for coastal greenbelt development. Location

characteristics including physio-chemical characteristics of soil and water, general

vegetation of the area, tolerant/acclimatized species, land availability, land

ownership aspects, etc. can be considered in selecting the areas for greenbelt

development.

9. Development of environmentally compatible economically viable greenbelt

packages for the coastal areas towards sustainable ecological rehabilitation of the

coastline. Here, the efforts can be focused on developing an agroforestry system

composed of mangroves and agroforestry trees (and other crops like coconut

palm), which have survived the impacts of tsunami.

Although a total greenbelt developed with plants of environmental, economic and

social values are the aims envisaged in the above proposals, it may be noted that there is a

scope for agroforestry development as a part of such green belting programme, which

will have an impact on the entire coastal wetland system. It may be note that the

Kuttanadu wetlands associated with tsunami-affected areas are very poor in tree

elements, the plantation of which will be relevant in containing the impact of pollution

and other environmental hazards associated with the wetland system, at the same time as

providing resources for supplementing the means of livelihood of the people.

CHAPTER XII

Impact of tsunami on the mangroves of the Kerala coast, with particular reference to the maximum impact zones

R.C. Pandalai1, K. Swarupanandan1, A.R.R. Menon1, and A. Mohandas2

1 Kerala Forest Research Institute, Peechi 680 653, Trichur, Kerala.

2 Tropical Botanical Garden and Research Institute, Pacha Palode, PO., Trivandrum.

12.1 INTRODUCTION

On 28 April 2005, the Kerala State Council for Science, Technology and Environment

(KSCSTE) organized a one-day meeting to discuss and prepare a report on the recent

tsunami disaster that hit the Kerala coast on 26 December 2004. The Council

entrusted the task to the Kerala Forest Research Institute (KFRI) and the Tropical

Botanical Garden and Research Institute (TBGRI), to investigate the impact of

tsunami on the natural coastal vegetation, the mangroves. Accordingly a team of

scientists consisting of, Dr. RC Pandalai, Dr. K. Swarupanandan, and Dr. ARR

Menon from KFRI and Dr. A. Mohandas from TBGRI visited Edavanakkad of

Ernakulam Dist., Arattupuzha of Alappuzha Dist., and Alappad of Kollam Dist.

during 11 and 13 May 2005, and investigated the impact of tsunami on the mangroves

and other coastal vegetation and also people were contacted for their experience on

the impact. The following is a report of the investigation.

The Report comprises of two distinct aspects:

1. The impact of tsunami on the vegetation, especially the mangroves, as evidenced by field visits, and

2. The impact of tsunami on the vegetation based on the interpretation of remote sensed data, both prior to and after the incidence of tsunami.

The remote sensed digital images of southern Kerala coast (before tsunami dated 19

Feb. 2004 and after tsunami dated 27 Dec. 2004) were procured from NRSA,

Hyderabad and were processed using ERDAS 8.7 version software. The ground truth

of the impact of tsunami on the vegetation was inferred from field check, as indicated.

Fig. 1. Map of southern Kerala coast showing the study sites, Edavanakkad, Arattupuzha and Alappad, affected with tsunami.

Edavanakkad

Arattupuzha

Alappad

12.2 OBSERVATIONS

12.2.1 Impact of tsunami on vegetation: through field check Observations on the state of vegetation at each location visited (see Fig.1) are given

separately.

i. Edavanakkad (Ernakulam Dist., Latitude: 10o 08' Longitude: 76o 13’)

Site details: Edavanakkad is located in the Vypin Island, about 16 km northwest of

Cochin. Vypin is a narrow island oriented in the north-south direction bordering the

Arabian Sea on the west and the Vembanad backwaters on the east. The Edavanakkad

village is moderately populated, mostly dominated by fishermen communities. The

general landscape of Edavanakkad consists of settlements, coconut groves (frequently

intermixed with the tree, Thespesia populneoides) (Fig.2 and 3) and the shrimp farms;

the shrimp farms are smaller aquatic enclosures made of artificial bunds that segment

the backwaters. Land reclamation process is very active in the area; people plant

coconut trees in artificially raised heaps of soil in the swamps/ water (Fig.4). The land

is about one meter above the sea level and under normal conditions; the waves do not

intrude into the land. A greater portion of the shoreline was provided with sea walls of

granite boulders.

Fig. 2. The general landscape of Edavanakkad

Fig. 3. The mangrove vegetation exists only as thickets edging homesteads and the shrimp farms

Fig. 4. A view of land reclamation using coconut trees.

Mangroves: The existing mangrove vegetation is highly fragmented, being restricted

largely to the bunds of the shrimp farms, or edges of the coconut homesteads, and

dense and extensive mangrove forests are lacking in the region. The existing

mangroves are only reminiscences of the once extensive mangrove vegetation and

survive as small thickets. They are highly fragmented due to the on going

shrimp farming activities, alignment of new approach roads to the main

land/island systems, and their elimination associated with the expansion of

homesteads.

The mangrove vegetation can be categorized into three different communities:

1. The Excoecaria agallocha-Avicennia officinalis community: This community

is restricted to the bunds of shrimp farms and edges of the homesteads being

the banks of the backwaters. The plants encountered in the community are

Excoecaria agallocha (common), Avicennia officinalis (quite frequent),

Rhizophora mucronata (occasional) and Derris trifoliata (common). All the

species mentioned are basically trees, except the last being a climber. All the

tree species are represented only in their sapling stage; large trees above 10

dbh are practically absent. The zonation which is very characteristic of good

mangrove forest stands is not at all seen in the stands here.

2. Acanthus ilicifolius community: Acanthus ilicifolius is a gregarious primary

colonizer found growing towards estuarine channels in natural mangroves. In

the Edavanakkad area, although large extents of inter-tidal banks are available

A. ilicifolius community is found restricted to very small areas.

3. Acrostichum aureum community: This community is made up of the swamp

fern, Acrostichum aureum, and is generally found along the reclaimed bunds

of coconut groves.

None of the Thespesia trees, common in coastal area were found damaged (Fig.5). A

few individuals of Acrostichum aureum, the swamp fern, were toppled and carried

away by the killer waves.

Fig. 5. A tree of Thespesia populneoides affected by tsunami; note the exposed roots owing to acute

soil erosion.

People’s perception and impact on the locality: According to the local people, the

tsunami waves hit the village around 3 pm in the afternoon and there had been only a

few reported human casualties from the area. The waves intruded into the houses (Fig.

6), carried away the people in to the backwaters and many managed to escape in

country boats. The sea walls were almost completely shattered (Fig.7) and the road

along the coast has been damaged with severe soil erosion and uprootment of coconut

trees. The large boulders of the sea walls were thrown apart to a distance of ca. 10 to

15 m inside. Most of the coconut trees seem to have survived the impact except a few

along the shoreline and nearer.

Fig. 6. A post-tsunami view of the area. Note the shattered building and the unaffected green belt.

Fig.7. A view of the shattered sea wall. Note the healthy coconut grove adjoining partially damaged

road.

To sum up, the mangrove stands in the Edavanakkad area have not been affected

seriously by the tsunami waves.

ii. Arattupuzha (Alappuzha Dist., Latitude: 9o 13' Longitude: 76o 23')

Site details: Arattupuza is a thickly populated village located on the seacoast about

10-12 km away from Kayamkulam. The general landscape of the area is almost the

same as that of Edavanakkad with coconut groves, backwaters (Kayamkulam lake),

and the long stretch of narrow land edged by sea and the backwaters on either side.

However it differs from Edavanakkad in the absence of shrimp farms and the land

being not an island. The entire area of Arattupuzha is thickly populated.

Mangroves: The area is devoid of any mangrove vegetation except the Tharayil

Kadavu, being the insular projection flanking the Kayamkulam Pozhi (estuary). The

sea mouth of the Kayamkulam Pozhi (estuary) is safeguarded with two converging

‘pulimuts’ (Fig.8). At Tharayil Kadavu, a small area of ca. 3-4 ha, being a mangrove

patch, is dominated by thickets of Avicennia marina. Occasionally, here and there a

few plants of Excoecaria agallocha, Clerodendrum inerme, Acanthus ilicifolius and

Premna serratifolia were also seen. As in other places, the Avicennias have been

heavily lopped to reduce the stand into a thicket and no large trees of the species were

seen. Around the homesteads, trees of Thespesia populneoides are common with

occasional plantings of Terminalia catappa (Indian almond).

Fig. 8. The Arattupuzha area showing the mouth of the estuary with ‘pulimut’s.

People’s perception and impact on the locality: The tsunami waves struck the area

around 10.30 am in the morning, in three to four consecutive short-lived surges. The

killer waves are said to have grown to a maximum height of around 6-7 m; with the

succeeding in surges, the height of the killer waves grew higher and higher. The

entire market place with 20-25 shops, the black-topped approach road and the ferry

service point were completely destroyed (Fig.9). The sea encroached almost 10 m

inwards the land and deposited a sand bed elsewhere in the estuary. Most of the

people escaped in country boats, as the killer waves repeatedly struck the coast line; a

few of them however rescued themselves by hanging on the trees of Terminalia

catappa.

Fig. 9. Nearly 30 shops were completely destroyed at Alappad, making the area barren.

Fig. 10. Acute soil erosion and sea encroachment in to the land.

Fig. 11. A few saplings of Excoecaria agallocha and many plants of Acanthus ilicifolius were killed on

the sea shore.

With the intrusion of sea in to the land, around 10-15 coconut trees were toppled as

evidenced by the stumps (Fig.10). In other homesteads, the coconut trees were not

seriously affected. Along the sea shore, a few saplings of Excoecaria agallocha (a

tree) and bunches of Clero-dendrum inerme (a shrub) were found to be toppled and

killed, mainly due to the torrential effects of the waves and the consequent removal

of soil /sand behind the plants (Fig.11). On the other hand, the gregarious patch of

Avicennia officinalis that existed as a thicket did not seem to have been affected by

the killer waves (Fig.12).

Fig. 12. The mangrove thickets at Alappad.

iii. Alappad (Kollam Dist., Latitude: 90 04' Longitude: 760 30')

Site details: Alappad, the area adjoining Arattupuzha, is situated in the southern

flanks of the estuarine belt of the Kayamkulam Lake. Azhikkal (Kavilkadavu),

Cheriya Azhikkal (Srayikkad), Parayakkadavu, Ayiram Thengu, etc, are the areas

most affected by tsunami. The landscape of the area does not differ from that of

Arattupuzha. The area is densely populated and the homesteads, the coconut groves,

are rich in trees of Thespesia populneoides, than elsewhere.

Mangroves: Though fairly good patches of mangroves are seen towards the inner

corridors of the estuary (Kayamkulam Lake) 300 m away from the coastline,

mangroves are absent along the shoreline. In the Ayiram Thengu area, mangroves are

restricted to a small preserve (4-5 ha area) dominated by Lumnitzera racemosa,

Rhizophora mucronata, Avicennia marina and Aegiceras corniculatum. Other lake

shores are devoid of mangroves, though occasional mangrove elements are found

distributed here and there and they do not qualify to be considered as a normal

mangrove stand. Mangroves occupying the inner fringes of the ruminating lakeshore

are more or less. undisturbed with taller and larger trees and were not at all affected

by the killer waves. The trees of ‘poovarasu’ (Thespesia populneoides), copious in the

homesteads were also not affected The prominent absence of large mangrove patches

in the area did not provide an opportunity to assess the impact of tsunami on the

vegetation, though the impact was indicated by the drifted dead trees obtained from

the Ayiram Thengu area. Acute surface soil runoff was also observed in a few

localities of Alappad region (Fig.13).

Fig. 13. Soil erosion due to tsunami and the exposed feeder roots of coconut trees.

II. Impact of tsunami on vegetation: through aerial photographs and atellite imageries s

The tsunami affected area of Kerala coast was studied using Aerial photographs

(Task-108, Runs-1 to 14, 52 to 69 of 1986 in 1:12,500 scale) and Satellite imageries

(IRS1C LISS III) of 19th February 2004 (pre-tsunami) and of 27th December 2004

(post-tsunami). The post- and pre- tsunami scenes were studied using the software

ERDAS, 8.7 version.

Aerial photographs: The aerial photographs were visually interpreted using standard

photo interpretation techniques and photo elements. The interpreted information was

transferred to MAPINFO software for further layering and analysis. The map thus

generated (Figs. 14 and 15) was used for the study of tsunami affected area. It was

also observed that there is no appreciable change in the vegetation status, before and

after Tsunami except minor damages to the coconut plantations along the seashore.

The patches of Mangroves (about 1.21 km2) along the inland coast and the associated

species are more or less intact except in the Kayamkulam Pozhi area, where minor

damages were observed to the coastal vegetation mainly due to uprooting of

vegetation and sand deposition.

Fig. 14. Tsunami affected regions in Arattupuzha areas in Alapuzha district

based on aerial photographs and SOI toposheets. Hatched area in purple colour shows the affected region.

Fig. 15. Tsunami affected region of Alappad area in Kollam District based on aerial photographs and SOI toposheets. Hatched area in purple colour shows

the affected region. Satellite imageries: The temporal data analysis of the coastal region (IRS 1C LISS III

of 19 Feb 2004 and 27 Dec. 2004) based on the spectral reflectance value was also

done to evaluate the changes in the coastal vegetation and shallowness of the sea coast

(Figs 16-21). The tonal variation of the imageries before and after tsunami was the

criterion for evaluation.

Since the pixel resolution of the imageries was of 23 m, minor changes in the

vegetation could not be identified; the changes in vegetation can be observed only in

imageries of very high resolutions like CARTOSAT.

The data on shallowness of the sea coast measured perpendicular to the coast in

meters using the tools available in ERDAS software are given in Table 1.

As clearly indicated from the data, the soil reflectance value from the sea bottom

along the sea coast has been changed considerably due to sand removal and re-

deposition; after the tsunami, maximum decrease was observed at Arattupuzha and

minimum at Perumpally Tura. On the contrary, the shallowness of sea increased at the

Kayamkulam Pozhi.

Table 1. Extent of shallow sea from the coast before and after tsunami in Alappuzha/

Kollam coasts (Distance in meters perpendicu-lar to the coast). Extent of Shallow sea from the coast (m) Locality

Before tsunami After tsunami Arattupuzha 461.69 81.12 Nallanikal Tura 279.73 150.66 Ramanchery Tura 245.35 180.76 Perumpally Tura 170.47 126.25 Kayamkulam Pozhi 138.44 182.60 Azhikkal 153.70 23.32 Panakkada 106.00 43.57 Alappadu 292.93 13.89

Fig. 16. Pre-tsunami imagery (True colour composite) of Arattupuzha region of 19 Feb. 2004

(Scale: 1:50,000 approx.). Vegetation in green, water spreads in black and sand deposits in

whitish grey along the coast.

Fig. 17. Post-tsunami imagery of Arattupuzha region of 27 Dec. 2004 (Scale: 1:50,000

approx.). Vegetation in green, water spreads in black and sand deposits in whitish grey along

the coast.

Fig. 18. Pre-tsunami imagery (True colour composite) of Kayamkulam Pozhi region of 19 Feb.

2004 (Scale: 1:50,000 approx.). Vegetation in green, water spreads in black and sand deposits

in whitish grey along the coast.

Fig. 19. Post-tsunami imagery of Kayamkulam Pozhi region of 27 Dec. 2004 (Scale: 1:50,000

approx.). Vegetation in green, water spreads in black and sand deposits in whitish grey along

the coast.

Fig. 20. Pre-tsunami imagery (True colour composite) of Alappad region of 19 Feb. 2004

(Scale: 1:50,000 approx.). Vegetation in green, water spreads in black and sand deposits in

whitish grey along the coast.

Fig. 21. Post-tsunami imagery of Alappad region of 27 Dec. 2004 (Scale: 1:50,000 approx.).

Vegetation in green, water spreads in black and sand deposits in whitish grey along the coast.

DISCUSSION

The coastal belt along Edavanakkad (Ernakulam Dt.), Arattupuzha (Alappuzha Dt.)

and Alappad (Kollam Dt.) is moderately to thickly populated with the homesteads and

houses located very close to the sea shore, often some of them jutting into the sea

front.

Man-made plantations of coconut (Cocos nucifera) intermixed with jack (Artocarpus

heterophylla), poovarasu (Thespesia populneoides) and Indian almond (Terminalia

catappa) constitute the dominant sylvan landscape of the coastal vegetation. Though

meager casualties of tree crops, especially coconut trees, were observed the larger tree

populations escaped the onslaught of the killer waves. In addition to helping in

breaking the force of the tidal waves, these trees served as escape routes for a number

of individuals who took shelter in these trees to rescue themselves.

The estuarine coastal belt and its associated natural mangrove vegetation are highly

dissected due to various anthropogenic activities. As a result, extensive mangrove

vegetations expected of the inter-tidal areas are missing and are in a highly degraded

state, having transformed in to a thicket-physiognomy. Nevertheless, the mangrove

patches were found only slightly affected by the tsunami waves; a few instances of

toppled coconut trees and some uprooted shrubs were the only detectable impact. In

other word, the impact on mangroves was not specific to any individual plant species.

Elsewhere, it has been pointed out that presence of shelterbelts and mangrove

vegetation helped in reducing the impact of coastal disasters (KFD, 2005 a, 2005 b).

Our findings also go along with these observations.

Even though there is not much damage to the vegetation detected in IRS imageries,

the shoreline changes with reference to sea shallowness are remarkable. An attempt to

evaluate the sea shore changes with regard to the depth of sea, based on the soil

reflectance value from the sea bottom, indicated that because of the increase in sea

depth, in future the impact of the waves during monsoon may be of higher order. The

water spread area has widened after the tsunami as seen in the imagery. A very

detailed study is essential for a critical evaluation.

Despite the massive structure, the sea walls were less effective being a structure in

continuum, without break or openings permitting water to dissipate and the tidal force

to dampen. Had the sea walls been discontinuous with occasional gaps, coupled with

shelterbelt plantations of tree crops/mangrove vegetation might have diminished the

disaster impact, as the vegetation would have served as a porous and effective barrier

than the continuous engineering structures like sea walls.

ACKNOWLEDGEMENTS The investigators are thankful to Dr. AE Muthunayagam, Executive Vice President,

Kerala State Council for Science, Technology and Environment (KSCSTE), for

giving us an opportunity to investigate the impact of tsunami on mangroves. The

investigators are thankful to Dr. C.S.P Iyer, Senior Scientist, Regional Research

Laboratory, Council of Scientific and Industrial Research (CSIR), Trivandrum, for his

guidance, Dr. JK Sharma, Director, Kerala Forest Research Institute (KFRI), Peechi,

and Director, Tropical Botanical Garden and Research Institute (TBGRI),

Trivandrum, for their keen interest in pursuing the study. Dr. Sharma also kindly

arranged to get the satellite imageries at short notice from NRSA and offered valuable

comments for improving the manuscript. We also thank to Dr. R. Gnanaharan,

Research Coordinator, Kerala Forest Research Institute for facilitating the field visits.

We are also thankful to Mr. VS Ramachandran, Research Fellow for assisting in

report preparation.

REFERENCES

KFD, 2005 a. Workshop papers. Workshop on Forestry for Disaster Management,

March 2005, Thiruvananthapuram. Kerala Forest Department,

Thiruvananthapuram.

KFD, 2005 a. Varuna Parvam. Workshop on Forestry for Disaster Management,

March 2005, Thiruvananthapuram. Department of Forests and Wildlife,

Government of Kerala. Thiruvananthapuram.

CHAPTER XIII

RECOMMENDATIONS

13.1 Introduction

The devastating effects of the past tsunami advocating that it is not only wise but

also essential to implement the provisions of Coastal Zone Management notification

(1991) of the Ministry of Environment and Forests. It would be prudent to leave a safe

buffer zone from the shoreline. It has demonstrated that sea walls are not the panacea for

coastal erosion problems.

It is essential to acquire capabilities to predict tsunami occurrence. For this,

tsunami measurements from the deep ocean are required. The idea of measuring tsunami

in the deep ocean and actually reporting such data in real time is scientifically

challenging but feasible. The scientific emphasise should be on better predictions of

earthquake centres and intensity, the physics is tsunamis and the consequent run up and

inundation patterns. It is also essential to prepare detailed run up and inundation maps to

understand the consequences of tsunamis. We need a comprehensive multihazard

measures, since Kerala coast is vulnerable to various natural hazards.

13.2 Approach Toward Multi Hazard Safety Measures In Coastal Areas

a. General measures

• Adopting integrated multi-hazard approach with emphasis on cyclone and

tsunami risk mitigation in coastal areas

• Implementation of early warning system for cyclones and tsunamis

• Streamlining the relief distribution system in disaster affected areas

• Design, practice and implementation of evacuation plans with emphasis on self

reliance for sustenance with the locals (coastal community)

• Component on planning for reconstruction and rehabilitation should be added in

disaster management plans at all levels

• Emphasis on mental health and to socio-psychological issues should be accorded

in every plan

• Identification and strengthening of existing academic centers in order to improve

disaster prevention,

• Capacity building programmes to be taken up on priority basis

o Training of all concerned including community

o Public awareness programmes

o Enhancing capabilities of the Institutes working in field of disaster

mitigation and management

b. Specific Measures for safety from Tsunamis/Storm Surges

Structural measures:

1. Construction of cyclone shelters

2. Plantation of mangroves and coastal forests along the coast line (bioshield)

3. Development of a network of local knowledge centers (rural/urban) along the

coast lines to provide necessary training and emergency communication during

crisis time

4. Construction of location specific sea walls and coral reefs in consultation with

experts

5. Development of break waters along the coast to provide necessary cushion against

cyclone and tsunami hazards

6. Development of tsunami detection, forecasting and warning dissemination centres

7. Development of a “Bio-Shield” - a narrow strip of land along coastline.

Permanent structures should come up in this zone with strict implementation of

suggested norms. Bio-Shield can be developed as coastal zone disaster

management sanctuary, which must have thick plantation and public spaces for

public awareness, dissemination and demonstration.

8. Identification of vulnerable structures and appropriate retrofitting for

tsunami/cyclone resistance of all such buildings as well as appropriate planning,

designing, construction of new facilities like:

• Critical infrastructures e.g. power stations, warehouses, oil and other

storage tanks etc. located along the coastline.

• All other infrastructure facilities located in the coastal areas Public

buildings and private houses

• All marine structures

• Construction and maintenance of national and state highways and other

coastal roads

Non-Structural Measures:

1. Strict implementation of the coastal zone regulations

2. Mapping the coastal area for multiple hazards, vulnerability and risk analysis upto

taluka /village level. Development of Disaster Information Management System

(DIMS) in all the coastal states.

3. Aggressive capacity building requirements for the local people and the

administration for facing the disasters in wake of tsunami and cyclone, ‘based on

cutting edge level’

4. Developing tools and techniques for risk transfer in highly vulnerable areas

5. Launching a series of public awareness campaign throughout the coastal area by

various means including AIR, Doordarshan & Other Media.

6. Training of local administration in forecasting warning dissemination and

evacuation techniques

c. SPECIFIC MEASURES FOR SAFETY FROM TSUNAMIS

The important observed effects of Tsunamis and possible preventive design

solutions are listed in Table

Table. Phenomenon of Inundation

EFFECT DESIGN SOLUTION

Flooded basement Choose sites at higher elevations

Flooding of lower floors Raise the buildings above flood elevation

Flooding of mechanical electrical &

communication system &

equipment

Do not stack or install vital material or equipments

on floors or basement lying below tsunami

inundation level

Damage to building materials &

contents

Protect hazardous material storage facility located

in tsunami prone area.

Contamination of affected areas

with water borne pollutants

• Locate mechanical systems & equipments at

higher location in the building

• Use corrosion resistant concrete & steel for the

portions of the building

Hydrostatic forces (Pressure on

walls by variation in water depth on

opposite sides

• Elevate building above flood level.

• Provide adequate openings to allow water to

reach equal heights inside & outside of buildings.

• Design for static water pressure on walls.

Buoyancy floatation or uplift forces

caused by buoyancy

• Elevate building to avoid flooding.

• Anchor building to foundation to prevent

floatation

Saturation of soil causing slope

instability and/or loss of bearing

capacity

• Evaluate bearing capacity & shear strength of

soil that support building foundation &

embankment slopes under condition of saturation.

• Avoid slopes or setbacks from slope that may be

destabilized when inundated

d. Specific Design Principles for Tsunami • Know the Tsunami Risk at the site • Avoid new developments in Tsunami Run-up Areas • Site Planning Strategies to reduce Tsunami Risk • Tsunami Resistant Buildings – New Developments • Protection of existing buildings and infrastructure – Assessment, Retrofit,

Protection measures • Special Precautions in locating and designing infrastructure and critical facilities • Planning for Evacuation

13.3 TSUNAMI WARNING AND COMMUNICATION SYSTEM a. Tsunami Warning System The Present status of Tsunami Warnings in India.

Tsunami is least probability event in India. As such, there is no codal provisions

of Tsunami warnings in India as yet though, there is a good seismological network in

India to record any earthquake within the country and its neighborhood. The need of a

Tsunami Warning Centre (TWC) in India is now being conceptualized at the Government

of India level.

India Meteorological Department (IMD), is working on a proposal to set up a real

time earthquake monitoring system in India. The Department of Ocean Development in

collaboration with Departments of Space and IMD under Department of Science and

Technology is evolving a plan of tsunami warning system in the Bay of Bengal and the

Arabian Sea. The data from observing points to Warning Centre(s) will be sent through

satellite links, Specific systems called Deep Ocean Assessment and Reporting of

Tsunamis (DART) using Bottom Pressure Recorder, acoustic modem, acoustic release

system, battery pack bolted to platform and float action and recovery aids will be

deployed.

b. International Status of Tsunami Warning and Communication System

Present techniques of Tsunami prediction are severely limited. The only way to

determine, with certainty, if an earthquake is accompanies by a Tsunami, is to note the

occurrence and epicenter of the earthquake and then detect the arrival of the Tsunami at a

network of tide stations. While it is possible to predict when a Tsunami will arrive at

coastal locations, it is not yet possible to predict the wave height, number of waves,

duration of hazard, or the forces to be expected from such waves at specific locations.

Following most common methods of detection is in use:- • Japan has a network of land/sea sensors that records seismic activity and feeds

information to a national agency able to issue evacuation warnings within a minute of

occurrence of any earthquake. Earthquake warning issued by Japan Meteorological

Agency are relayed via satellite to the Municipal offices and automatically broadcast

from several sets of loudspeakers.

• Pacific Ocean issues warnings of tidal waves heading in a particular direction.

• Presently land and sea based sensors connected to satellite based link are available.

• Satellite telemetry is used for data collection and dissemination; receive and display of

Tsunami warning utilizing existing Geostationary operational Environmental Satellite

(GOES) and Data Collection Interrogation System (DCIS).

• Developing Tsunami and earthquake data base verification, Tsunami model, preparation

of hazard assessment maps for the coast line combing historical and modeling result,

establishment of seismic and tidal sensors using satellite telemetry to provide early

warning information.

• Extensive network of seismic and tidal station, as well as communication systems, to

ensure that the warning information is prompt and accurate.

13.4 INSTITUTIONAL ARRANGEMENTS AND DESIGN CRITERIA FOR TSUNAMI / CYCLONE MITIGATION a. Institutional Arrangements

• The present three-tier disaster management structure i.e. national, state and district to continue, with tsunami risk management added to the natural hazards.

• Development of ‘Disaster Information Management System’ (DMIS) upto village level

• Development of Disaster Management Sanctuaries along the coast, which will have facilities like simulators, museums, mock ups, plantation, capacity building training facilities etc.

• Constitution of special Task Force with representation from IMD, MUD, DST, Department of Forest and Environment, ISRO/DOS, AIR, Doordharshan, Fisheries, soil conservation, Town and Country Planning Organization, Navy, Coast Guard etc. under respective state disaster management authorities.

• Capacity building at the local level in terms of o Training o Organization development o Institutionalization of the programmes and o Public awareness

b. Development of Design Criteria Basis of Design Criteria 1. Considering the multi-hazard proneness of the coastal districts, the design criteria will have to cover the following aspects: 2. Design wind velocity under cyclone condition. 3. Effective wind pressure near sea coast. 4. Height of storm surge with concurrent tide level. 5. Tsunami effects

o Height & velocity of Tsunami wave o Hydrostatic water pressure. o Debris Impact o Wave break impact.

6. Earthquake effects – Design seismic co-efficient 7. Fire safety 8. Flood inundation & flood flow (velocity of flow). 9. Building aspects

o Shape, Size & Height of building. o Use importance of the building.

o On stilts or without stilts o The roof to act as shelter, hence flat (in that case design live load for the roofs. o Choice of building material and construction technology o Durability of the building (design life). o Thermal comfort.

Use Importance of the Buildings 1. Ordinary (housing, storage) 2. Important (hospital, school, fire station, power house, substation, telephone exchange,

VIP residence etc.) 3. Very important installations, cyclone/tsunami shelters Performance Level Desired

o Minimum – Non-collapse though structurally damaged. o Safe – Damaged but without significant structural damage. o Operational – Capable of avoiding/resisting all expected hazards & forces.

13.5 INSTITUTIONAL ARRANGEMENTS FOR DISASTER MANAGEMET IN THE STATE 13.5.1 NODAL AGENCY

The Secretary, Disaster Management Department shall be the Relief (to be

renamed as Disaster Management) Commissioner of the State. The district administration

should be the focal point for implementation of all governmental plans and activities. The

actual day-to-day function of administering relief is the responsibility of the Collector/

District Magistrate who exercises coordinating and supervising powers over all

departments at the district level. The Panchayati Raj Institutions can be effective

instruments in tackling disasters through early warning system, relief distribution,

providing shelter to the victims, medical assistance etc. (Fig. 4).

State Disaster Management Authority

State Institute of Disaster Management

Department of Disaster Management

State Crisis Management Committee

Village level Disaster Management teams

Control room for emergency operation

Crisis Management Group

District Disaster Management Committee

State Disaster Management Policy

State Disaster Management Act

Fig 4. INSTITUTIONAL MECHANISM FOR DISASTER MANAGEMENT IN THE STATE

Other than the national, state, district and local levels, various institutional

stakeholders who are involved in disaster management at various levels including the

police and para-military forces, civil defence and home-guards, fire services, ex-

servicemen, non-government organisations (NGOs), public and private sector enterprises,

media and HAM operators should also be assigned specific responsibilities.

Nodal agencies for various types of disasters are also to be identified such as

Indian Meteorological Department for climate and earthquake related disasters; nodal

agencies for geological disasters, chemical , industrial and technological disasters,

biological disasters and man-made disasters could be Centre for Earth Science Studies,

Kerala State Council for Science, Technology and Environment, Geological survey of

India, Department of Industries, Health Department and the Police Department.

The Armed Forces have historically played a major role in emergency support

functions such as communications, search and rescue operations, health and medical

facilities, transportation, power, food and civil supplies, public works and engineering,

especially in the immediate aftermath of disaster. Disaster management plans should

incorporate the role expected of them so that the procedure for deploying them is smooth

and quick.