Modeling Hydrologic and Water Quality Responses to Grass Waterways

Abstract

The impact of vegetation filter strips on runoff, sediment yield, and atrazine loss from a cultivated field was investigated using a physically based, distributed watershed model. The field to which the model is applied has a gentle to flat sloping surface covered by a thin topsoil layer underlain by a claypan and is located in the Goodwater Creek watershed, a USDA research site in central Missouri. The model, which works on a cell basis, was developed to route runoff, sediment, and soluble chemical downslope from one cell to the next. The spatial variability of soil, depth of the topsoil, and vegetation are allowed among cells; each cell, however, is represented as a homogeneous unit. Our investigation indicates that changing waterway cover from natural sparse vegetation to dense grass has great potential for retarding runoff and reducing sediment loss, but it is not effective for controlling atrazine loss on claypan soils.