Impact of Climate Change Projections and Best Management Practices on River Flows and Sediment Load

The impact of climate change and best management practices (BMPs) on flow and sediment load at a watershed outlet is presented in this study. Climate change scenarios include future daily temperature (maximum and minimum) and daily precipitation projections made by an Atmospheric Ocean Global Circulation Model (AOGCM) for the years 2046 to 2065. Daily precipitation data are further down-scaled to station level in the watershed area. An Optimal Control Model (OCM) developed by coupling a semi-distributed hydrological model, Soil and Water Assessment Tool (SWAT), with a genetic algorithm (GA) identifies the least cost design (sizes, types, and locations) of structural BMPs while meeting treatment goals at a watershed-scale for the years 2001–2005. Considering a requirement for 10% reduction of peak flow and sediment load for the years 2001 through 2005 and assuming the current landuse pattern will remain the same, the model is run with the current and future climate change scenarios; the performance of BMPs for two different time periods is compared. The model is demonstrated on Silver Creek watershed in Illinois.