Erosion risk mapping using rusle with GIS: case study of Büyük Menderes river basin of Turkey

Soil erosion causes loss of soil nutrients, decline in crop yields, and reduction in soil productivity. Moreover, soil moved by erosion carries nutrients, pesticides and other harmful farm chemicals into rivers, streams, and ground water resources. Subsequently, protecting soils from erosion is important to sustain landscapes and human life. Geographic Information Systems (GIS) have emerged as a powerful tool for handling spatial information and interact well with erosion models to provide robust problem solving capabilities useful for effective decision making. Erosion models often require moderate to high amounts of spatial data, which can be effectively handled through GIS. The Universal Soil Loss Equation (USLE), later Revised (RUSLE), is a relatively simple model that has remained one of the most practical methods for estimating soil erosion potential and the effects of different management practices for over 40 years. Coupling GIS and RUSLE has been shown in many cases to be an effective approach for estimating the magnitude of soil loss and identifying spatial locations vulnerable to soil erosion. The objective of this research was to develop a user-friendly GIS-based application that could quickly estimate soil loss in Büyük Menderes, which is a Mediterranean River Basin through the integration of GIS and erosion modelling. RUSLE was chosen to model erosion due to its simplicity, wide acceptance/use, and manageable data requirements. This study emphasizes that spatial information technology including, remote sensing and GIS with RUSLE erosion modelling approach could be utilized in the spatial and quantitative assessment of erosion risk. The study showed that 2% of the basin is subject to very high erosion risk, 11% has high erosion risk, 33% has medium erosion risk. This erosion risk assessment also pointed the hot spot areas of erosion to related authorities to help in their erosion prevention efforts