46.-Assessment of sedimentation in a reservoir using remote sensing- Some case studies

Abstract

Periodic evaluation of sediment deposition and the estimation of available live storage capacity in a reservoir is an integral component of optimum water resources management. The conventional techniques of sedimentation quantification in a reservoir, like the hydrographic surveys and inflow outflow methods, are cumbersome, costly and time consuming. Further, prediction of sediment deposition profiles using empirical and numerical methods requires large amount of data and the results obtained are still not accurate.

R.emote sensing data, through its spatial, spectral and temporal attributes, can provide synoptic, repetitive and timely information regarding the revised waterspread area in a reservoir. By using the digital analysis techniques and the geographic information system in conjunction, the temporal change in waterspread area is analysed to evaluate the sediment deposition pattern in a reservoir. In this paper, the remote sensing approach in general, has been described. The approach is explained through some case studies. Inaccuracy in the assessment on account of mis-interpretation of waterspread area, selection of tail end etc. has also been highlighted.