Soil Loss and Reservoir sedimentation assessment of Kaddam watershed using Geographical Information systems and Remote sensing Techniques

Abstract

Soil loss is a significant threat in both onsite and offsite issues of worldwide, and more attention is required to compensate for the soil loss, loss of fertility, nutrients, valuable minerals, and silt deposition in reservoirs. The geographical distribution of soil loss was evaluated using the Universal Soil Loss Equation (USLE) model, and the Kaddam watershed's reservoir sedimentation was calculated using a trapezoidal equation. Rainfall erosivity (R- factor) minimum and maximum values in Kaddam and Indervally rain gauge stations were 416.25 and 492.93 MJ.mm/ha.h.yr. Soil erodability factor (K-Factor) is 0.3 t ha h/ha/mj/mm for clayey soils, and slope length found as up to 380 (dimension less) and crop and management factors considered on local crops and agricultural practices in Kaddam watershed. According to the USLE equation, the maximum spatial distribution of soil depletion is 60 tonnes/hectare/year, whereas the sediment yield assessment through the reservoir is 57 t/ha/year. Many researchers used methods to assess the soil loss or yield separately but not integrated in single environment. To fulfil the gap, chosen Kaddam watershed, computed two methods separately and simulations compared with observed hydrographic survey shown satisfactorily. Hence, predication and method of the present study can adopt other reservoirs.