Assessment of sediment deposition rate in Bargi Reservoir using digital image processing

Abstract

A reservoir is an integral component of a water resources system. Periodic evaluation of the sediment deposition pattern and assessment of available storage capacity of reservoirs is an important aspect of water resources management. The conventional techniques of quantification of sediment deposition in a reservoir, such as hydrographic surveys and the inflow-outflow methods, are cumbersome, costly and time consuming. Further, prediction of sediment deposition profiles using empirical and numerical methods requires a large amount of input data and the results are still not encouraging. Due to sedimentation, the water-spread area of a reservoir at various elevations keeps on decreasing. Remote sensing, through its spatial, spectral and temporal attributes, provides synoptic and repetitive information on the water-spread area of a reservoir. By use of remote sensing data in conjunction with a geographic information system, the temporal change in water-spread area can be analysed to evaluate the sediment deposition pattern in a reservoir. A case study, related to the assessment of sediment deposition in Bargi Reservoir, Madhya Pradesh State, India, is presented. The reservoir was completed in 1988 and no hydrographic survey has yet been carried out. Under these circumstances, the sedimentation assessment using satellite data can guide the dam operators in updating the elevation-area-capacity table of the reservoir. The images for nine dates from the IRS-1C satellite, LISS-III sensor have been analysed using the ERDAS/IMAGINE software. The resulting sedimentation rate in the zone of study is about 229 m3 km−2 of catchment area per year.