Sediment Yield from Agricultural Watersheds

Abstract

Several methods of calculating sediment yield from agricultural watersheds are reviewed and three are applied to six Hungarian catchments where multi-year accumulated sediment yields have also been measured as reservoir deposition. The methods used to estimate sediment yields are regional regression, the Universal Soil Loss Equation (USLE) with sediment delivery ratio and a modified USLE using a runoff model. The only hydrologic data available for use are those on precipitation. Criteria for selecting a desirable procedure are presented, and, on the basis of these criteria, an event-based version of the modified USLE with rainfall data as input is deemed the best, primarily as this method results in the most accurate estimates. The other two methods gave much less accurate results with all estimation methods overestimating measured sediment yields.