Abstract
Field experiment was preformed to determine the effect of soil moisture state on the runoff volume and soil loss by using standard flumes with dimension of 100*12*30 cm. The flumes were filled with soil materials The results of this study pointed out that the moist state primarily appeared increasing the runoff volume and soil loss in comparison with dry state. The rate of soil loss under water erosion was found to be proportionally related with the soil moisture content. Also the results of the statistical analysis by regressing rainfall depth against runoff depth showed that threshold value of the surface runoff resulted from moist soil state were less than that of dry state.
