19. Geospatial Technologies for Assessment of Reservoir Sedimentation

Soil erosion in the catchment area of the reservoir catchment leads to sedimentation problem in the reservoir thereby affecting its both live and dead storage capacities that reduces the designed life span and planned economic benefits. Conventional techniques for assessment of reservoir sedimentation not only involve lot of manpower but also time intensive and costly to implement. Remote sensing techniques by virtue of its synoptic coverage and multidate observations are reported to be quite useful for computation of reservoir live capacity. These surveys are fast, economical and reliable. The present study was taken up to update the stage—area—capacity curves (estimating loss in the live storage capacity) for 30 reservoirs spread across India, where delineated waterspread area corresponding to satellite pass forms the important basis. The difference between the present satellite measured waterspread area and that of a previous survey (obtained through hydrographic survey) is the areal extent of silting at these levels. Integrating the area over different levels gives an estimate of volume of silting observed by satellite between the maximum and minimum reservoir level.