ASSESSMENT OF RESERVOIR SEDIMENTATION IN CHHATTISGARH STATE USING REMOTE SENSING AND GIS

In a modern scenario, reservoir sedimentation is vital problem as every reservoir are bound to suffer a loss in their storage capacity potential because of silt load, for short or long period of time. For water resources planning and land & water management system, computation of soil erosion, sediment conveyance and its deposition in reservoir, irrigation canal, hydropower systems should be taken as top priority. The capacity and useful life of reservoir should be known for harvesting the maximum quantity of water in the whole year for treatment plant, irrigation, hydroelectricity, flow balance, flood control etc. Conventional techniques used for the evaluation of the reservoir capacity and the sedimentation in a reservoir, like inflowoutflow technique and hydrographic survey, Integrated bathymetric survey etc are cumbersome, clumsy, time consuming and uneconomical, and even they involve huge manpower. An alternative of traditional methods, GIS & Remote sensing technique is used in present work to compute the loss of storage capacity and sedimentation in Murrumsilli reservoir situated in dhamtari district, Chhattisgarh state, India. Several scenes of Linear Image Self Scanning (LISS III) digital data of Indian Remote Sensing (IRS) satelliteIRS-1D/P6 have been imported and normalized difference water index (NDWI), image rationing and slicing techniques have been implemented to detect the water and non-water pixels from the images using Integrated Land and Water Information System 3.0 (ILWIS 3.0), a GIS software. The revised water spread area at various elevations has been computed which will provides the revised capacity of the reservoir. Final results obtained by study shows that in Murrumsilli reservoir total deposition of sedimentation is found to be 29.956 MCM and percentage loss of capacity is equals to 18.37 % from 1923 to 2015. It also shows that rate of sediment deposit are about 0.32 MCM/year.