Mapping Ecological Vulnerability in Outer Himalayas

8/14/2019 Mapping Ecological Vulnerability in Outer Himalayas

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MAPPING ECOLOGICAL VULNERABILITY IN HIMALAYAS: A CASE

STUDY OF DEHRADUN VALLEY

POONAM KUMRIA

Miranda House, University of Delhi, Delhi, India.

[email protected]

1. INTRODUCTION

Bio- physical material and man-made features are dynamic and changing rapidly the different

aspects of the land resource. Land is an important natural asset for human being and source of

sustenance of mankind. Land use can be defined as the utilization of the resource by human

beings with an emphasis on functional relationship between man and nature [1]. Ultimately, land

utilization has been transforming land resource or natural ecosystem to social ecosystem. The

structure of land use in any region is an expression of a continuous process of evolution through

interplay of ecological, technological and institutional influences. Ecological influences take the

form of physiographic elements like – location, altitude, geology, soil and climate in particular.

These influences basically determine the spatial distribution and pattern of land use. Cultural

influence like science, technology, industrial development, urbanization, irrigation and water

management system determines the spatial intensity and structure of land use.Land use pattern change over time and space in response to changing environmental and social

forces. With remote sensing data, study tries to identify different classes of land use in the

Dheradun valley. Using it as a base, change detection analysis has been done for the last three

decades. This analysis study changes in the land use/ land cover during this space of time and to

extract trends in intensity and direction. This information forms an important part of decisions

made at local level. Understanding land use change and dynamics of each category provides

clues for resource utilization. The Himalayas has complex physiographic expression. The

intervention caused with rapid population growth has brought great changes to the resource base

and its utilization pattern. It is increasing the ecological vulnerability over the time period.

2. The Study Area

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mailto:[email protected]



Dehradun is a longitudinal valley lying between 290 55' and 300 30' N latitude and 770 35’ and

780 24' E longitudes. Its length is 100 kms and width varies from 20 to 25 kms covering an area

of 2250 sq. kms. The valley is bounded by the lesser Himalaya in the North and Siwaliks in the

South, while rivers the Ganga and the Yamuna form eastern and western limits [3]. Within the

valley the elevation ranges between 315 meters to 1000 [4]. Administratively, the Doon valley

is a part of Vikasnagar, Dehradun, and Rishikesh Tahsils, which is further divided into four

development blocks- Vikasnagar, Sahaspur, Raipur, and Doiwala.

The word 'Doon' means valley. Doon is tectonic in nature. The hills are of mainly sedimentary

and metasedimentary rocks. Slopes are quite steep and relief is very high. The wide altitudinal

variation ranges from low lying valley to the Himalayan ranges, leading to variation in lithology

and topography; it results in variations in climatic and edaphic conditions. It has produced great

variety of vegetation. Dehra is the largest town in the Dehradun district with an elevation of 670

meters. Dun was founded in 1699 by Sikh Guru Ram Rai, who built temple here. The valley does

not have many large scale industries but does have some chemical industries and limestone

quarries, which are polluting the environment. Over exploitation of land resources will cause

serious, irreparable damage to the valley and its inhabitants. Taking this in consideration the

present study is aimed at reviewing ecological conditions of land resource in the valley.

3. Objectives

a) To detect land use changes since 1970s to 2009.

b) To identify ecological vulnerable zones in the valley

1. Methodology

For the purpose of evaluating the changes in land use and land cover in the Doon valley,

Landsat TM and ETM Images were analyzed. The entire study is mapped through digital

interpretation of False Colour Composite (F.C.C.) obtained LANDSAT satellite. Multi Spectral

Scanner digital Images for Oct. 1975, Thematic Mapper digital Image for 1985, and 1995; and

ETM+ Image for 2005 and 2009 were downloaded. A subset study area was carved from the

original image. After downloading the data into computer, rectification is carried out in each

image to provide Latitude and Longitude information into raw satellite scene using raster based

geometric corrections. Rectification carried out in geographic projection is re-projected in shape



of polygonal projection and the scene is geo-coded with using toposheets printed by the Survey

of India [2]. Each of the multi-spectral data sets were classified into 9 different land use types-

Dense forest, Open Forest, Agriculture, fallow land, scrub land, barren land, build up area,

plantations and water bodies. The classification was done using supervised digital classification

techniques.

In order to establish the land use changes within the study area a change matrix has been

prepared which significantly shows changes in every class. The analysis has also be done with

categorization of land use change to three major classes- positive, negative, and no change. On

the basis of different geo factors and land use classification, using multivariate cluster analysis a

geo- ecological pattern has been generated which created ecological vulnerable zones in the

valley. There are identifiable potential areas highly prone to degradation, erosion and landslides

in the valley. Identification of these areas can help in local planning and management of

resources in the valley.

2. Conclusion

• There are positive changes in agriculture, barren and scrub land.

• There are negative changes forest and water areas.

• Plantation area has also increased in the valley.

• Most conspicuous change throughout the period is the changes in dense forest area to

open forest.

• Buildup area is increasing due to high urban growth.

• Highly vulnerable zones identified in the lower Himalayan region, where built up area

has increased due to population and urban growth.

1. Bibliography

[1] Blaikie, P. And Brookfield, H. (1987): Land Degradation and the

Society, Routledge, London.



[2] Forest Survey of India (2008): The State of Forest Report, 2005, Ministry

of Environment and Forests, Government of India, Dehradun.

[3] Singh, I.J., Das, K.K. and Kushwaha, S.P.S. (2003): Forest Stock

Assessment using IRS LISS - II and PAN merged Data in Timli Forest Range,

Dehradun, Photonirvachak: Journal of Indian Society Remote Sensing,vol. 31, no. 1, pp. 49-56.

[4] Walton, H.G. (1911): Gazetteer of Dehradun, Natraj Publishers,

Dehradun.

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Mapping Ecological Vulnerability in Outer Himalayas