TR(BR)-1/2000-2001 : Application of GIS for the Assessment of Soil Erosion Using universal soil loss equation

Abstract

Soil erosion from a catchment is the result of complex processes, which is controlled by various climatic, topographic, geologic, geomorphic, and land use characteristics. Scientific planning for soil conservation and water management requires knowledge of the relations among those factors that cause loss of soil and water and those that help to reduce such losses. Controlled studies on field plots and small watersheds have supplied much valuable information regarding these complex factor and their interrelations.

Information on sediment yield from a catchment can be modelled using lumped and distributed models. However, for field applications, a reliable and simple method is required. The Universal Soil Loss Equation (USLE) is highly useful tool for predicting sheet and rill erosion under various conditions of land use and management. In the present study, USLE has been used to estimate the average soil loss from Hire Nadi catchment, in Yelberga taluk, Koppal District of Karnataka, under different conditions.

Due to its data handling and analysing capabilities, GIS is becoming important in natural resources management. It has proven its applicability for the analyses of various components of hydrologic cycle. In the present study Integrated Land and Water Information System (ILWIS) has been used for the estimation of USLE parameters. A, rage soil loss from the study area is calculated as 25.98 tons/ha/year. Various maps have been prepared showing land use types in the study area, and regions of potential soil loss, actual annual and seasonal soil loss.