Assessment of management strategies to control water erosion: A GIS based RUSLE approach.

Abstract

The aim of this study is to assess the management strategies used to control soil erosion over the watersheds of Ain Berda, Oued El-Aneb, and Oued Fregha; three adjacent watersheds in the northeast of Algeria. The assessment of soil loss amounts at an annual basis was conducted through a GIS-based RUSLE approach using data from both open access databases and field observations. The performances of three common types of support practices (Terracing, Strip cropping, and Agroforestry) were evaluated and compared. For a better assessment, the modelling of soil loss amounts was performed in two ways “without” and “with” integrating the existing support practices. In both cases, the application of the RUSLE model showed in general acceptable soil loss amounts due to the dense vegetation cover that characterizes the studied areas. Yet, the results indicated that the application of erosion control measures in agricultural areas was successful, especially in Ain Berda watershed where the reduction in the annual soil loss was estimated at about 14.79%. Concerning, the watersheds of Oued El-Aneb, and Oued Fregha the participation of these support practices in the reduction were relatively low, of 7.72 % in Oued El-Aneb and 2.42% in Oued Fregha. By comparing the techniques among themselves, it appears that terracing is the most applied technique in the three watersheds and logically gave the greatest reduction rate which was about 12.96%, 5.86%, and 1.42% in Ain Berda, Oued El-Aneb, and Oued Fregha respectively. The study comprised, also a patience of the farmers’ opinions about their views of erosion problems and their conservation knowledge and practices.