Abstract

In arid lands, rainwater harvesting can play animportant role in making more water available since most of therainfall runoff evaporates. If rainwater can be collected, it willform a useful resource. Jordan is classified as one of the poorestcountries regarding water resources with an arid and semi-aridclimate. For these limited and vital sources of water, goodestimation of rainfall runoff quantity and quality can enhancethe sustainability of water harvesting projects. The hydrologicestimations of runoff quantities and qualities are essential, andseveral techniques to achieve that exist. Revised Universal SoilLoss Equation (RUSLE) is one of the widely used techniques toassess the soil erosion due to runoff, by assessing other physicalfactors that affect the soil loss. RUSLE combined fiveparameters to identify the soil loss rate: rainfall erosivity,topographic, soil erodibility, vegetation cover and management,and land management. Based on RUSLE results, areas areclassified as a highly soil loss rate if the annual rates exceeded 20tons per hectare. The Asreh watershed is a 196 km2 area that ismostly wasted land and receives an annual rainfall between 50and 300 mm per year. The RUSLE equation inputs parametersfor the study area are found and the equation is applied for thewatershed. Results of RUSLE application on the Asrehwatershed showed that the average annual soil loss rate is about7.8 tons per hectare, about 73% of the area are classified as lowsoil loss rate with less than 10 tons per hectare per year, andonly 13% of the area is classified as a high soil loss rate of morethan 20 tons per hectare per year.