bangladesh climate vulnerability: floods and cyclones
DESCRIPTION
May 16 in Parallel Session 3E "Earthquakes, Hurricanes, Floods & More: Dealing with Natural Disasters". Presented by A. Atiq Rahman, BCAS.TRANSCRIPT
Bangladesh Climate Vulnerability: Floods and Cyclones
BANGLADESH CENTRE FOR ADVANCED STUDIES House 10, Road 16A, Gulshan 1, Dhaka 1212, BangladeshPhone: 8818214-7, 9851234, 9852904; Fax: 9851417Website: www.bcas.net
Dr. Atiq RahmanExecutive Director: Bangladesh Centre for Advanced Studies (BCAS)Founding Chairman: Climate Action Network – South Asia (CANSA)
Visiting Professor: Fletcher School of Law and Diplomacy , Tufts University and Harvard University, Boston, MA, USA
IFPRI 2020 Conference on Building Resilience for Food and Nutrition SecurityDate: 15-17 May, 2014
Addis Ababa, Ethiopia
Outline of the presentation
1. Bangladesh: Most vulnerable country
2. Extreme Events: Climate Impacts
3. Cyclones: A Case Study
4. Floods: A Case Study
5. Responses: By Communities
CLIMATE CHANGE CASE STUDY: BANGLADESH VULNERABILITY
1. Sea Level Rise
2. Cyclone (Intensity & Frequency)
3. Deeper Penetration of Saline Water
4. Erratic Rainfall
5. Flood (Intensity & Frequency)
6. Drought
7. River Bank Erosion
8. Health
9. Food Security
10. Water Security
11. Land slide in CHT
12. Migration
Relief Map of South Asiahttp://www.flickr.com/photos/ocean_of_stars/2785428699/sizes/o/in/photostream/
Nepal
India
Myanmar
Pakistan
Bangladesh occupies a unique geographic location spanning a stretch of land between the mighty Himalayan mountain chain on the north and the open ocean on the south. It
is virtually the only drainage outlet for a vast river basin complex made up of the Ganges, Brahmaputra and the Meghna and their network.
The Complex River Systems
1. Unique geographical location2. Dominance of flood plain3. Himalayan drainage eco-system
Water Tower
Water Sink
The variability of onset, breaks and duration of the summer monsoon have enormous affects on water resources, agriculture, economics, ecosystems, and human mortality throughout South Asia and Bangladesh as well.
Location of Bangladesh in relation to major river basins in South Asia
Extreme Events: Global
Earth quakeTsunami
Volcanic Eruption
Flood & River ErosionCycloneDrought
Land slideHeat/Cold waves
Sea Level Rise and Salinity Intrusion
Nat
ural
Haz
ards
Extr
eme
Clim
atic
Eve
nts
Climate Change Related
Tectonic
Types of hazards
How Climate Change Increases Risk
Changes in the magnitude,coverage and frequency of climaticextremes
Changes in average climaticconditions and climate variability,affecting underlying risk factors
Generates new threats, which aregion may have no or littleexperience in dealing with.
10
Climatic Extreme Events
Temperature rise and heatwaves in China, Russia, Mongolia, Korea, Japan, India and South East Asia
Increased and erratic rainfall induced frequent floods in Bangladesh, India, China and South East Asia
Cyclones and Typhoons in South Asia, Bangladesh, India, Philippines, Japan and China
11
Climatic Extreme Events
Number of recorded disasters doubled globally from approximately 200 to over 400 per year in the past two decadesNine out of 10 disasters are now climate related
Sea level rise and salinity in South Asia, Bangladesh, India, Maldives, Sri Lanka, Indonesia and SEA
Droughts in South Asia including India and Bangladesh, South East Asia, China and Mongolia
Source: Swiss Re sigma Catastrophe database: Include floods, storms, droughts, forest fires, cold wave & frost, hail and other
Change in Frequency of Hazard Event
13
14
Global cost of weather extreme events is increasing to a great extent
15
Number of houses damaged per million people per year (using 21 datasets)
Source: Global Assessment Report on Disaster Risk Reduction 2011, UNISDR
16
Global Cyclones Incidence and Intensity
17
Extreme Events: Bangladesh
Hazard Class Map Ranking of multi-hazard maps used for preparing the risk-index : Cyclone ( high risk-5, risk-3,wind risk- 1) Flood (Severely flooded due to major
river floods – 3, flash flood due to major river-2, other flood-1)
Riverbank erosion(severe erosion-2, erosion -1)
Drought (very severe drought prone areas – 2, severe drought-1)
Sea
Lev
el R
ise
Cyclone
Saline Zone of Bangladesh
Err
atic
Rai
nfal
l
Flood
Flood 2004
Flood Frequency
FloodedArea
Return period (Years)2 5 10 20 25 50 100
Areaaffected %
20 30 37 43 52 60 70
Last 30years
5 3 2 2
Last 10years
3 2 1 1
Inundated Area during Different Floods and Number of Occurrences in Last 30 Years
For Example: A flood event with return period of 20 years has already occurred twice during the last 10 years.
EXISTING DROUGHT SITUATION,AND DROUGHT SITUATION IN THE YEARS 2030 & 2075
EXISTING DROUGHT
DROUGHT CLASSES (KHARIF SEASON)
Very Severe DroughtSevere DroughtModerate DroughtLess Moderate DroughtSlight Drought
Very Slight to NilSevere & ModerateModerate & Less ModerateSunderbansForest
ADDITIONAL DROUGHTPRONE AREAS IN 2030
ADDITIONAL DROUGHTPRONE AREAS IN 2075
Rive
r Ban
k E
rosio
n
Health
Source: IPCC AR4, 2007
Migration
Source: IPCC AR4, 2007
Internal initially
External later
No one wants to leave their land
Global justice: Issues of migration
Human rights: Issues of migration
Migration already happening
Strategic dimension of migration
Key Climate Change Stresses and Impacts on CHT
• Hills support sub-ecosystems which are rich in species and biodiversity
• These give livelihood supports to the hilly people
• Key stresses in CHT– Temperature rise– Erratic rainfall– Extreme events -Flood
and Landslide
Maxim
um
Temperature
Cyclones
1970
19912007
Source: DMB Situation Report,2007
• According to ICZMP coastal area includes 19 districts. Among these 16 coastal districts are considered in present study
• Total area: 42,500 km2
• Total population: 31 million (BBS, 2001)
History of major cyclones
Cyclone
Cyclones in Bangladesh
37
• Wind speed will increase around 10%for one degree Celsius increase in temperature.
• Frequency and Intensity of cyclone will be more.
Climate Change Impact on Cyclone
Recent Cyclones in the Subcontinent
SIDR: Bangladesh: 2007
NARGIS: Myanmar: 2008
RASHMI: Bangladesh: 2008
AILA : Bangladesh: 2009
MOHASEN: Bangladesh: 2013
CYCLONE
40
Floods
Frequency of Flood
42
Flood
Flood 2004
FLOOD
44
Causes
a. Heavy rainfall
b. Heavy siltation of the river bed reduces the watercarrying capacity of the rivers/stream.
c. Blockage in the drains leads to flooding of the area.
d. Landslides blocking the flow of the stream.
e. Construction of dams and reservoirs
f. In areas prone to cyclone, strong winds accompaniedby heavy down pour along with storm surge leads toflooding.
Flood
Chronology of Big Floods
Economic Loss and Fatality of Floods
RADARSAT ScanSAR Wide image, 23 July 2004
Climate Change Impact on River Flow
Sources: A study conducted by CEGIS using the hydrological model SWAT
BrahmaputraAnnual: 710,000 Mm3
Increase: 5-10%
Annual: 150,000 Mm3
Increase: 7-10%
MeghnaGanges
Annual: 350,000 Mm3
Increase: 8-17%
Climate Change Impact on River FlowCont..
• Flooding event will increase both in terms of intensity and frequency
• The average flooding depth will increase about 0.3 m
• The 50 year return period of flood event will be a 20 year event
Climate Change Impact on Flooding
The Linkage
Climate Change
Global Warming (Anthropogenic)
Temperature Rise•LST•SST
Variation in Precipitation Ice Melting and Sea Level Rise
Flood Drought Cyclone and Storm Surge
Loss of Property + Injury + Death
DISASTER
Food Security IPCC estimates that, by 2050, rice production in
Bangladesh could decline by 8 percent and wheat by 32 percent
Decrease production of livestock, Increase of pest attack Decrease production of fisheries
Development over time in Climate Change Impacted scenario and Adaptation Achievements
Dividend in climate smart development
Deve
lopme
nt ($
)
Climate impacted development loss
Climate smart adaptation benefits
Time (t) years
54
Floods and Cyclones pictures
Climate Disasters in Bangladesh
Responses: Some Examples on Community Based
Adaptation
Source: Char Livelihood Program of DFID
Raised Plinth Height
Hom
este
ad G
arde
n on
Ra
ised
Plin
th
Raised Plinth of Toilet
Livestock During Flood
Raising Plinth
Preservation of Household Assets Over False Ceiling
Storage of Food during Flood
Storage of Safe DrinkingWater & Dry Food
Community based rain water harvesting
Household based rain water harvesting
Floating Garden During Flood
Locally Known as Baira Cultivation
Raised Tube Well
Store Extra Furnace
Protecting from Erosion
Protecting Income Generating Activity
Water Collection in Hilly Region
Community People Using the Water of Re-excavated Pond
Pond Sand Filter
Household Based Rain Water Harvesting in Drought Prone Area
Drip Irrigation
Household Based Irrigation Farming
Crab Farming in Saline Water
Saline Tolerant Rice
Chickpeas in Drought Area
Seed storage system/seed bank
Adjustment in Cropping pattern Hanging Nursery
Making Soil heap
Local Adaptation Practices in Nepal
A Greenhouse in Pakistan
Examples in Agriculture
Nigeria Morocco
Senegal India
Example in Agriculture
Australia
Examples in Agriculture
Farming in Brazil
Intensive Potato Farming in Canada
Examples in Agriculture
Farming in New Zealand
Examples in Agriculture
Farming in Philippines
Examples in Agriculture