Study of Soil Loss in Main Wadis of South Sinai

Universal Soil Loss equation (USLE) is a powerful tool that is widely used by conservationists in the Unites States and many foreign countries, it substantiated the usefulness and validity of (USLE) empirical erosion model for this purpose. It is also applicable to non-agricultural conditions such as construction sites. In this work, we need to predict the amount of soil loss occurs through the main wadis in South Sinai due to the flash floods occurs in this region by predicting the appropriate values for the (USLE) six factors like rainfall drop erositivity (R), slope steepness (S), slope length (L), soil erodibility (K), Crop management factor (C) and Support Practice Factor (P), using Geographic Information System (GIS) tools to facilitate the numerical computation for the (USLE) erosion model factors by using raster calculator algorithm based on remote sensing data. Global Precipitation Climatology Centre (GPCC) daily precipitation data used to estimate the rainfall drop erositivity (R) for a storm event occurs in twenty fifth of October two thousand and fifteen, where a field survey measurement for sediment loss volumes accumulated upstream two dams located on wadi watir to be used as a calibrated values for our model results, also the geological, morphological and land use remote sensing data used in estimating the other factors for our study area. The results estimated for soil loss volumes accumulated upstream the two dams are 10181.27 m3 and 9926.068 m3, while the field measurement volumes are 7440 m3 and 8478 m3 respectively. Thus, the calibration factors ranges between 0.73 to 0.85 for the sediments values results from the USLE model which should be taken into consideration. The present results provide a vital database to control soil erosion which effect on the ecosystem and the effect of control structures constructed on the main wadis on the sediments which arrive to shorelines.