SCS-CN based modified universal soil loss equation

Abstract

Modified Universal Soil Loss Equation (MUSLE) is generally used for estimation of sediment yield on storm basis from a small agricultural watershed. To calculate runoff factor of MUSLE, recorded runoff hydrograph are required. In the present study an attempt has been made to develop a sediment yield estimation model based on the curve number and rainfall. The significance and applicability of the developed model is then assessed by comparing the sediment yield estimated value and MUSLE estimated sediment yield values for the different combination of hydrological and the geomorphologic characteristics of the watershed. Also the developed (CN-MUSLE) model is applied by using observed values from two agricultural watersheds. The MUSLE and CN-MUSLE estimated values were then compared with the observed sediment yield. The developed CN-MUSLE model is capable to estimate sediment yield values almost with same estimation accuracy as the MUSLE model for all combinations of input variables. The developed CN-MUSLE model has better adoptability as it does not require recorded runoff hydrograph instead it estimates sediment yield based on storm precipitation and curve number of the area.