SEDIMENT YIELD ESTIMATION USING GIS

A method has been developed in the present study for the determination of the sediment yield from a catchment using a GIS. The method involv es spatial disaggregation of the catchment into cells having uniform s oil erosion characteristics. The surface erosion from each of the disc retized cells is routed to the catchment outlet using the concept of s ediment delivery ratio, which is defined as a function of the area of a cell covered by forest. The sediment yield of the catchment is defin ed as the sum of the sediments delivered by each of the cells. The spa tial discretization of the catchment and the derivation of the physica l parameters related to erosion in the cells are performed through a G IS technique using the Integrated Land and Water Information Systems ( ILWIS) package.