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 hydrographie 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 hydrographie 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 nr' km"" of catchment area per year.
