|
|
|
Sustainable Development in Mountain Ecosystem at Watershed Level - A Geospatial Approach
4. Role of Geo-spatial Technology
Due to high relief and terrain complexity, mountainous areas require a 3-dimensional representation for spatial modeling. Geospatial tools constitute a versatile and varied range of techniques whose full potential is yet to be realized especially if we talk about disasters in Indian context. Several organizations are developing regional and national scale monitoring programs in which GIS plays a central role. Remote sensing integrated with geospatial techniques provide a powerful tool for the mapping, assessing, evaluating and analyzing the present, past and future status of the natural resources of a watershed. Remotely sensed data may not be sufficient alone to act, as indicators for sustainability studies but it can be helpful when integrated with socio- economic dataset.
5. Huinyal Watershed- A Case Study
Huinyal Watershed constitutes an important watershed of Huinyal basin and Garhwal Himalayan range and forms a part of Tehri district. It lies between 300 05' N to 300 25'N and 780 15' E to 780 30'E. The average altitude varies from 600 to 2800 meters (approximately) above sea level. The watershed under study covers an area of approximately 260 Sq.kms approximately.
(Figure 1)
Physiography
The watershed falls under the middle Himalaya, composed of weak sedimentary and metamorphic formation. The slope varies from 3-5% to 50%. There are several streams negotiating through numerous scarpments, making the area topographically more complex. High hills in the north are imposing structures at about 2800 metres falling steadily to 600 metres msl at the southernmost tip of the watershed.
Drainage
The large part of the Garhwal is drained by major system of the Ganga River. Huinyal River is also part of the Bhagirathi system, which ultimately joins the Alaknanda at Deoprayag to form the main channel of the Ganga river.
Climate
Wide variations in the climatic conditions are found over different parts of Garhwal. The watershed enjoys a humid type of sub-tropical to temperate climate often subjected to extremes of weather conditions and experiences moderate to heavy rainfall during monsoon and winter period. Seasonal snowfall is common at higher altitute during winter.
Geology
The Himalayan Mountain chain, of which Garhwal is a part, is amongst the youngest mountains in the world. Geologically the area is unique in a sense that five different age groups of rocks were identified in the study area viz. Quartzite, shale, limestone, slate, and phyllite. All the rock types found in the area are structurally controlled and exposed in the northern slope. The northern slope is mostly weathered and covered by thick vegetation as compared to the southern slope. The southern slope exposes mostly quartzite, phyllite and states of Nagthat and Chandpur.
Soils
The nature and type of soil found in watershed varies from place to place. These are brown to grayish brown and dark gray in colour with moderate to high concentration of pebbles. Therefore, it has an important bearing on the life and well being of the people of this region.
Vegetation
The watershed is endowed with dense vegetation. The terrain complexity and altitudinal variability supports various temperate, subtropical and tropical species. Chir pine (Pinus roxburghii) is a dominant species in subtropical region largely confined to lower reaches of the watershed and south facing slopes. Oak (Quercus leucotrichophura) is another valuable species dominating in the cooler region. The notable presence are Ficus palmeta, Salix wallichiana, Acer ablongam, Rhododendron arboreum, Barberi asiatica, Ustica parviflora. Sal (Shorea robusta) has a characteristic presence in the lower hills adjacent to the valley area. Deodar (Cedrus deodara) and Blue pine (Cedrus wallichiana) and their associated species enrich the higher altitude areas.
Socio-economic Condition
The socio-economic condition of the area is not so good and people are mostly dependent on agriculture. Being a hilly terrain the villages are scattered all around the area in small clusters. The villages lack basic infrastructure facilities and due to this the overall development of the area is hindered. The houses are scattered due to the hilly terrain and without a proper connectivity. A significant number of the villages are inaccessible due to poor connectivity of the roads.
Material & Methods
Data used
- Satellite Data of Landsat TM , April 2001
- Topographic sheets number 53J/7 and 53J/8
- Field compass
- Field Performa/Questionnaires
- Population census 1991, from the respective block offices
- Forest Working Plan Report
- Relevant literatures/reports
Software
- ERDAS IMAGINE 8.5
- ARC VIEW 3.2a
|
|
|