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Mapping and Quantitative Assessment of Vegetation of Jiribam Sub-Division, Imphal East District, Manipur, India using Remote Sensing and GIS

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Chapter

General Introduction

Introduction

Use of RS and GIS in Forestry

Development of RS and GIS techniques in

India

Application of RS, GIS and GPS in Forestry

Importance of conventional field sampling

techniques coupled with RS and GIS

Significance of the study

Objectives

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1.1 Introduction

The land use/land cover pattern of a region is an outcome of natural and socio-economic

factors and their utilization by man in time. Land is becoming a scarce resource due to

immense agricultural and demographic pressure. Hence, information on land use / land

cover and possibilities for their optimal use is essential for the selection, planning and

implementation of land use schemes to meet the increasing demands for basic human

needs and welfare. This information also assists in monitoring the dynamics of land use

resulting out of changing demands of increasing population. Viewing the Earth from

natural resource base over time. Over the past years, data from Earth sensing satellites

resources and studying environmental change. Remote Sensing (RS) and Geographic

Information System (GIS) are now providing new tools for advanced ecosystem

management. The collection of remotely sensed data facilitates the synoptic analyses of

Earth.

Forests constitute a key natural resource as well as a source of environmental services,

and are considered valuable, because they provide a wide range of benefits to the society:

products (timber, fuelwood, fodder, green manure, minor produce, medicines, etc.),

ecosystem services (soil conservation, hydrological regulation, carbon sequestration,

etc.) and -

biodiversity hotspots of global significance. The state stretches across a geographical

area of 22,327 sq. km which constitutes 0.7% only of the total land surface of India. The

terrain of the state shows a lot of variation with altitudes ranging from 55m above MSL

to 2,995m above MSL. This has manifested itself in various climatic regimes ranging

from temperate to sub-tropical climate. This variation in turn has lead to the presence of

a large diversity of forest resources of the state. The state experiences annual average

rainfall of 1430mm. The region lying in the Indo-Myanmar Biodiversity Mega hotpots

amongst the 34 biodiversity hotspots of the World.

Given the fact that a number of biologically rich areas like North-Eastern Region of

India are not fully explored and studied, many more species may still be discovered.

Hence, vegetation studies form a vital component of any natural resource management.


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An ideal forest monitoring should therefore provide information on the levels of each of

forest stocks or benefits being produced by a forest. Development of sound forest

conservation and management strategies requires an understanding of the spatial and

temporal patterns in the forest condition. Scientific management would need

comprehensive information on varying scale, forest cover type, resource component,

land use practices, socio-economic uses etc.

Several international conventions and agreements have stressed the importance of the

assessment of forest biodiversity. The assessment of forest biodiversity has recently

become a priority area for forest research. Forest biodiversity includes the diversity

within species, between species, and of ecosystems and encompasses not only species

diversity but also ecological structure, functions and process. Assessing this is potentially

an enormous task and any methods that can be adapted to reduce the amount of time

spent collecting data are therefore of interest. While biodiversity preservation is arguably

among the most important tasks facing ecologists, a great irony is that identifying the

location of biodiversity hotspots is among the most expensive (both monetarily and

intellectually) activities that ecologists can undertake. Great expenses can be incurred

during intensive field surveys and the taxonomic expertise required across diverse

assemblages of species can be daunting. Difficult terrain and inaccessibility makes

almost impractical to obtain information required for efficient management of the forest

resources with reasonable accuracy. For this reason, any method that can help to identify

biodiversity hotspots faster, better, cheaper, would be welcome.

Remote sensing represents an important tool for looking at ecosystem diversity and

various structural aspects of individual ecosystems. Recent developments in satellite

remote sensing and GIS coupled with user oriented computer programs allow to use

landscape ecological principles for biodiversity characterization at landscape level more

efficiently. Remote sensing has been used primarily to stratify habitats, vegetation types,

land use and other association. Environmental complexity can be spatially estimated

based on terrain and climate variability. The surrogate parameters determining the

phytodiversity have been taken into consideration for assessing biodiversity at landscape

level (Roy & Tomer 2000).


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1.2 Use of RS and GIS in Forestry.

Remote sensing (RS) is defined as the science and art that permits us to obtain

information about an object or phenomenon through the analysis of data acquired by a

sensing device without its being in contact with that object or phenomenon. The

Geographical Information System (GIS) is a set of tools and an organized collection of

computer knowledge and software with supporting data and personnel that captures,

stores, manipulates analyses and displays all forms of geographically referenced

information. GIS uses computer technology to merge the remote sensing images with

other data sets and to produce specially synthesized technological products which can

handle and analyse specially referenced data.GIS can store voluminous amount of spatial

(maps) and non spatial (tabular data) information. It has potential uses in forest

management and inventory.

Remote sensing technology has turned out to be one of the widely used means for

monitoring and managing forest resources not only in regional scale but also in global

scale. It can encompass synoptic view of large area coverage of forests anywhere on

earth. It has been widely recognised as the most appropriate technology for

complementing the ground based traditional survey and mapping activities. Remote

sensing observations can be used to differentiate forest cover types on the basis of forest

structure and species composition. Multitemporal remote sensing observations can be

used to separate forest management treatments (cutovers, thinning, plantings etc.), new

roads, insect damage, windthrow, burned or flooded areas from surrounding cover types

overtime. Landscape pattern and habitat fragmentation can also be measured and

quantified by using remote sensing observations.

The importance of Remote Sensing applications for the socio-economic development

of nations has been recognized since the era of aerial photography in the early part of

20th century. The photo-interpretation for forestry purposes was introduced by a German

forester in 1887. However, the aerial photographs were put to actual use in forestry only

first country to introduce use of aerial photographs in

forestry applications. During the same period, the technique was introduce in Germany,

Myanmar (Burma) and North Rhodesia. America, Japan and Indonesia introduced this

tion of satellite imagery for forestry related purpose is


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relatively new. The era of satellite remote sensing began with the launching of Landsat-1

in July 1972 by NASA, United States.

1.2.1 Development of RS and GIS techniques in India.

In India the trend in Geospatial Technology with reference to applications has

received a tremendous boost over the last fifty years. The Remote Sensing and space

technology in India has been realized effectively since 1960s. Application of this

technology has travelled a long way since then. Aerial photographs were first used in

1963 by G.A. Jones for the preparation of quick inventory of Kulu forests in Himachal

Predesh. Further forward motion in the utilization of aerial photographs in India gathered

momentum with the establishment of the Indian Photo Interpretation Institute (renamed

as Indian Institute of Remote Sensing in 1983) under Survey of India in 1966 for

imparting training in aerial Remote Sensing techniques. Aerial photographs are,

however, being used regularly since 1965 by the Pre-investment Survey of Forest

Resources Organisation (renamed as the Forest Survey of India). Besides, the other

organizations using aerial photographs for forestry purposes include NRSC Hyderabad, a

number of forest departments and remote sensing centres in states.

After the launching of Landsat-1 in 1972, the Landsat data is being regularly used

worldwide for forest mapping. The first ever forest cover mapping in India was carried

out using Landsat imageries pertaining to period 1981-83 at 1:1 million scale. The results

India has

launched successfully many Remote Sensing and communication satellites to its pride.

The first Indian Remote Sensing satellite (IRS-1A) was launched in 17th March, 1988.

The Indian Remote Sensing satellite system has the world's largest constellation of

Remote Sensing satellites in operation today which provides leadership and

continuity in earth observations through an operational earth observation

infrastructure. There are ten Remote Sensing satellites in operation CARTOSAT 1 &

2, CARTOSAT-2B, IRS-1C, IRS-1D, IRSP3, Oceansat-1, Oceansat-2, Resourcesat-1

and Technology Experiment Satellite, (T

natural resources survey and management.


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1.2.2 Application of RS, GIS and GPS in Forestry.

RS and GIS has a wide variety of applications in Forestry such as vegetation type

mapping, forest density stratification, forest inventory, forest management, forest

change/degradation assessment, forest working plans/stock mapping, forest fires, wildlife

habitat evaluation, biomass estimation, forest carbon pool assessment and biodiversity

characterization. Remote sensing methods can be used to map different forest types

according to a range of different classification methods, based on consideration of

different attributes. The use of remote sensing imagery to assess changes in forest cover

is of great interest to forest conservationists. Such analyses can be used to estimate

deforestation rates and patterns, which can be of value in identifying conservation

priorities and potential sites for forest restoration. Descriptions of the pattern of forest

landscapes can be produced from maps of land cover derived from field survey, aerial

photography, or satellite remote sensing imagery. Estimation of forest biomass (or total

organic matter content) is currently of great interest with respect to measurement of the

carbon sequestration potential of forests. Relatively few attempts have been made to

estimate biomass from satellite remote sensing data.

Using Geographic Information Systems (GIS), Remote Sensing (RS) and Global

Positioning System (GPS), usually called Three-S System can set up an information

administrative system of forest resource. Three-S system can quickly provide

information storage, searching and analysis. The present day computer technology

combined with the satellite data has a lot of potential in the field of forest inventory and

mapping. GIS is found to be effective in preparing, maintaining and carrying out

futuristic analysis on land-use planning and management. This is even more important in

hilly terrains where the physical constraint makes it difficult to update the information

very frequently and even availability of information is poor in comparison to adjoining

plains. Remote sensing provides an efficient and cost effective method of acquiring up-

to-date and accurate landscape and regional level information for use by resource

planner.

Global Positioning System (GPS) technology now offers efficient and cost-effective

ground truthing and land survey ability. Forest Survey of India (FSI) extensively uses

GPS in field data collection and ground verifications associated with forest cover


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mapping and inventory. GPS also finds use in projects undertaken by FSI such as

providing baseline information for working plan preparation, field digitization,

differential processing, locating sample plots, forest type mapping and forest fire

monitoring. Other applications deserving more focus of GPS use are biodiversity

assessment, ecological indices calculation, positioning/tracking of animals/birds,

rationalization of protected area boundaries, habitat & corridor mapping, location of

ecotourism sites and routes, preparation of vulnerable area maps by mapping poaching &

other illegal activities on forest resources.

Once a map has been produced from remote sensing data, it can be used as simply as a

visual aid for forest planning purposes or to inform a stakeholder consultation process.

Alternatively, a range of different quantitative analyses can be carried out, including

species habitat modelling, deforestation modelling, landscape pattern and forest

fragmentation analysis, and conservation priority-setting.

1.3 Importance of conventional field sampling techniques coupled with RS and GIS.

As a first step for proper forest land use, land consolidation works are to be done in a

sustained manner along with proper maintenance of the records. Forest land

consolidation should start with survey and mapping. For both survey and mapping,

conventional methods and modern techniques can be employed. Conventional methods

of survey and mapping have to be done with equipments like prismatic compass,

altimeter, measuring tape, ranging rods, drawing instruments etc. along with skilled

manpower. Cartography is done manually. Conventional methods are tedious, time

taking, cumbersome and the results obtained are also not accurate. Human factor or bias

comes in the picture while doing the works. Besides, revising or updating the map or

land records involves a long time frame. On the other hand, modern techniques of

mapping involve tools like GPS, Remote Sensing, GIS and Computers but no prismatic

compass, altimeters etc. Advances in modern technologies have rendered the forest land

consolidation works and maintenance of records easy, accurate, scientific, less time

taking and reliable. But these require professionals or trained manpower. Both the

techniques however, will require SOI Toposheets of suitable scale.

The remote sensing techniques provide the synoptic view of large areas which is not

possible by conventional ground survey methods. Satellite data are received periodically


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and the periodicity of data acquisition varies from one satellite to another. This capability

of satellites helps in updating the information and monitoring the changes at short

intervals. Remote sensing has a unique capability of recording data in visible as well as

invisible (ultra-violet, infrared, thermal infrared, microwave etc.) parts of

electromagnetic spectrum. Therefore certain phenomena which cannot be seen by the

human eye can be observed through remote sensing techniques. For example, the trees

and stands affected by disease or insect attack can be detected by remote sensing

techniques much before they are seen by human eyes. Remote sensing concerns with

electromagnetic energy from sun and its interaction with Earths features. But, quite

often, similar spectral reflectance by different earth features and dissimilar spectral

reflectance by similar earth features create spectral confusion leading to

misclassification. These problems can be overcome by systematic ground truth

information.

It is therefore, evident that although the conventional methods of data collection are

essential and should be continued the efficiency of data collection both in terms of cost

and time will increase manifold if these are supplemented and/or complemented by

remote sensing techniques. Nowadays one can easily survey and do mapping of an area

of interest such as village location map, plantation area, treatment area etc. within the

shortest possible time. However they require skilled/committed man power/labour.

Administrative maps, soil maps, management maps etc. can also be prepared, stored and

retrieved in digital form easily. Territorial units such as range, block, compartment etc.

can be easily mapped on the basis of visible/identifiable physical features such as

streams, ridges, roads etc. by digitization.

1.4 Significance of the study

Jiribam Sub-Division is rich in natural resources and a large number of people depend on

them in many ways. Being a sub-tropical type of climate, the vegetation of this region

was different from other parts of Manipur except in Indo-Myanmar border. A lot of

landscape changes have occurred due to developmental activities, increasing population,

plantations etc. in recent years. Good patches of forest are left only in some parts of the

study area. Very few work has been done in the forest of Jiribam Sub-Division. Little is


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known about NTFP collection, utilization, and marketing in Jiribam region despite their

great economic potential for the local communities and households here.

For the optimal utilisation of land resources, information on physical, ecological and

socio-economic conditions of the area should be comprehensive and up to date. At

present there is no detailed LULC map of the study area. This map is essential for

effective planning and management of the landscape. Quantitative information on the

structural status of the vegetation and floristic composition is essential for the better and

effective decision making. Spatial distribution, composition, economic and ecological

properties of vegetation in different cover classes and the pattern of their changes etc. are

pre-requisites for planning, utilisation and management of forest. Vegetation map is one

of the best ways to represent above mentioned information. Vegetation classification and

mapping have been considered significant in deriving basic information in the ecosystem

conservation and management.

To meet such an inevitable need of management, the present study has been undertaken

by using RS and GIS supplemented with conventional techniques and it includes the

following objectives.

1.5 Objectives

The objectives of the present study were as follows:-

1. Preparation of landuse/landcover map using RS and GIS technique.

2. Quantitative analysis of vegetation and patterns of plant species diversity.

3. Analysis of spatial patterns of forest fragmentation.

4. Inventorisation of non-timber forest products and analysis of their

utilization by local people.

general introductionshodhganga.inflibnet.ac.in/bitstream/10603/54555/8/08...roads, insect damage,...

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