Modeling Best Management Practices on Flow and Sediment using the Rangeland Hydrology and Erosion Model

Soil and water conservation is the keystone to sustainable livestock grazing and maintenance of native species on South Dakota’s rangelands. Rangeland conservation and management requires the ability to assess the potential impacts of best management practices on sediment yield and runoff in order to help mitigate negative effects of erosion and sedimentation on soil vegetation productivity and water quality. This study used the Rangeland Hydrology and Erosion Model (RHEM) to evaluate best management practices in the estimation of runoff and sediment yield on the Ash Creek Watershed located in western South Dakota. Runoff and sediment yield were determined for each best management practice scenario in RHEM and were then used as metrics to evaluate rangeland conditions against a baseline condition. Rangeland best management practices implemented in the Ash Creek Watershed were simulated by adjusting the land-cover and dominant vegetation type to represent rangeland in poor, fair, and good ground-cover conditions. The management of other land uses in the watershed was assumed to remain constant through the simulation period. The three different land-use scenarios were performed to determine the effects of varying vegetative cover on runoff and sediment yield at the hillslope scale through five selected hydrologic response units within Ash Creek