Application of GIS in assessment of soil erosion risk :

Abstract

Land degradation has already been treated as one of the most serious problem all around the world soil erosion is defined as the physical degradation of the landscape over time. The process is initiated when soil particles are detached from its original configuration by erosive forces such as rainfall. The soil particles may then be transported by overland flow into nearby rivers and oceans, Current developments in geographic Information systems (GIS) make it possible to model complex spatial information. A GIS is used in this project to determine. Soil erosion rate and risk throughout a watershed. Hydrological data is also analysed to give some understanding or the, watershed response to the primary erosive input rainfall. The goals of this, research project is to obtain the erosion rate from the model and erosion risk-area of the catchment. This study is a GIS-based to study which devotes to calculate annual soil loss value and erosion risk; seek for soil erosion trends linked with precipitation and land use in Mbale district on Mount Elgon region, Uganda. Revised Universal Soil Loss Equation (RUSLE) is implemented in the application to obtain the erosion risk in the catchment. The modelling is carried out for the years and is based oil ASTER remotely sensed data, digital elevation models, precipitation data from the study area, as well as existing soil maps from DSMW. Over exploitation of land is probably compensated by improved agricultural management and no significant increase in precipitation. Even if there are reports of more intense and increasing amounts of rainfall in the area this could not be verified, neither through analysis of climate data, nor by trends in estimated soil erosion risk and rate. The predicted surface soil erosion in Mbale catchment mostly depends on the slope conditions and precipitation records, while the major easily manageable factors are the conservation and cover management factors on the land.