Water erosion assessment methods: a review

Abstract

Water erosion is the removal of topsoil particles from the surface due to raindrop impact and runoff. Planning and implementation of conservation measures involve knowledge of the spatial pattern of erosion risk. For evaluating the spatial variation of soil erosion, selecting proper method of assessment is critical. The result of the review revealed that there is no single universal method that works everywhere in the world for assessing water erosion. Universal Soil Loss Equation (USLE) and its derivatives (revised [RUSLE] and modified [MUSLE]) were more popular empirical models in water erosion assessment. If the competition is between USLE and its derivatives, choose USLE or RUSLE for predicting long-time average soil loss and the area is dominated by rill and inter-rill water erosion. But, if the intention is to predict sediment yield from particular rainstorm events and the area is dominated by gully erosion, select MUSLE. Moreover, USLE is more suitable for agricultural land and low slope gradients, whereas RUSLE can be used in the nonagronomic area and a wide range of slope gradients. Water erosion assessment methods to be selected based on the intention of assessment and their appropriateness, applicability, and compliance with local conditions. © 2019 Indian Society for Hydraulics.