Remote sensing and GIS based catchment area treatment plan for soil conservation measures

Abstract

The fast growing development and ignorance of catchment area treatment plan during and after implementation of water resource project accelerating rate of sedimentation and disturbing the ecological balance in reservoirs and watersheds. The scientifically developed catchment area treatment plan identifies environmentally stressed areas, necessity and intensity of mechanical and biological measures to arrest further soil erosion and selection of spatial distributed locations of appropriate soil conservation measures. The Saaty’s analytical hierarchal process (AHP) based multi-criteria decision making tool based on nine spatially distributed erosion hazard parameters (EHPs) was applied for identification of priority subwatersheds. Various thematic layers such as geology, land use, soil, slope, drainage, geomorphology in weighted overlay technique (WOT) with decision rules were used to identify suitable sites for mechanical structures and areas for agronomic and biological measures of soil conservation. The Kodar reservoir is situated on river Kodar, a tributary of river Mahanadi in Chhattisgarh state of India has been selected for the study and divided in sixty seven sub-watersheds where nine EHPs were estimated and participated in Saaty’s AHP tool for identification of priority sub-watersheds. From the analysis, 117 km2 area of Kodar catchment can be put for intensify soil conservation measures because of high and very high priorities. The CAT plan for Kodar catchment consists of 37 gully plugs, 22 nala plugs, 21 boulder bunds and 6 check dams under mechanical measures with 101.61 ha land for afforestation, 114.86 ha for agro-forestry and 11.41 ha land for development of grazing land under biological measures. Under Panchayati rules in India, the gram panchayats are considered the administrative units for implementation of various conservation works and the areas of various agronomic and biological measures and mechanical structures suggested for different gram panchayats will be helpful for local administration to work in better way.