Evaluating of efficiency and accuracy of USLE, AOF, MUSLE-S and MUSLE-E models on estimating of event-based erosion amount (Case study: Sanganeh Soil Conservation Research Institute of Mashhad)

Numerous soil erosion models are developed and are applied in soil erosion studies as an acceptable feature in order overcome problem of lack of the adequate data on soil erosion and sediment yield. The Universal Soil Loss Equation (USLE) is one of the primitive empirical models in estimation of erosion that is used continuously. In this study, the accuracy of USLE model and some of its versions including MUSLE-E, MUSLE-S and AOF are evaluated in event-based in North Khorasan semi-arid regions. For this goal, the sediment due to 20 rainfall event is measured in experimental plots in Sanganeh soil conservation research Institute of Mashhad as a definitive of semi-arid rangelands of Khorasan. Then the erosion amount due to each rainfall event is estimated using selected various versions of USLE. Results obtained from application of each model compared with measured sediment values of selected plots and finally the accuracy and efficiency of mentioned models are evaluated. The obtained results of evaluation from 20 meters plots show a statistical relation and significant correlation between estimated amounts of MUSLE-E and MUSLE-S models and observed sediment. According to non-significant difference between models results and observation amounts of sediment (tMUSLE-E=1.53 and tMUSLE-S=1.63) and also lower statistics of RRMSE, efficiency of these two models in estimating erosion amount is also greater than the others. The USLE and AOF models cannot appropriately estimate observed sediment because they are not in good agreement.