A modelling study of the human impact on soil erosion processes within an agricultural watershed

An increased emphasis has been placed on improving and maintaining the quality of terrestrial water resources in the last two decades. This is especially true in the case of agricultural watersheds for which many intensive studies are focused on the information relating to the effects of land use, management and conservation practices or in structures on the quality and quantity of water. In this context, the authors introduced some major improvements to a physically based hydrological and soil erosion model, namely ANSWERS (Areal Nonpoint Source Watershed Environment Response Simulation). The modifications takes into account some human effects such as structural entities (roads, hedgerows) and linear shapes (tillages) within the catchment. Moreover, this improved model has been completely incorporated in a raster Geographical Information System (GIS) for simplifying the use of remotely sensed data and auxiliary data (i.e., hydrological and physical properties of the soil surfaces). Simulations conducted on an experimental agricultural watershed in Springvale (USA) for different patterns of agricultural planning stressed the importance of human influences on dynamic hydrological processes.