Digital image analysis techniques to estimate waterspread for capacity evaluations of reservoirs

The reduction of storage capacity of a reservoir between two elevation contours over a period of some years would be indicated by the reduction in contour areas at these elevation levels. The waterspreads, which are contour areas at different reservoir operating levels, were estimated for the Bhadra and Malaprabha reservoirs in the upper Krishna river basin using Landsat TM and IRS LISS II digital data, respectively. This paper discusses the digital image analysis strategy adopted for estimation of waterspreads and evaluation of the storage capacity of reservoirs. The possible error component of satellite derived waterspreads due to land-water mixed pixels is analyzed and discussed