GAMES—A Screening Model of Soil Erosion and Fluvial Sedimentation on Agricultural Watershed

Abstract

GAMES, the Guelph Model for evaluating the effects of Agricultural Management Systems on Erosion and Sedimentation, has been developed as a screening tool for watershed management. The basic philosophy behind the model is estimation of soil erosion by the Universal Soil Loss Equation and the percent field soil loss delivered to the downstream fields and the stream by a micro-delivery ratio function which incorporates surface roughness, land slope, hydrologic condition and the length of overland flow path. The model accommodates spatial units of variable size and shape. The time frame separates seasonal changes in soil erodibility, rainfall characteristics and land management conditions. The output generated for each field within the watershed are potential soil erosion, erosion rate, delivery ratio to the adjacent field, delivery ratio to the stream, sediment load and sediment yield rate. The application of the model to a small agricultural watershed shows the soil erosion and fluvial sediment sources and the watershed characteristics associated with these source areas.