Project Climate Change Impact on Hydrological Processes in a Lower Mississippi River Watershed.

Climate change is a long-term change in statistical distribution of weather patterns over periods of time that range from decades to millions of years. Impacts of climate change upon hydrological processes include increasing atmospheric water vapor content; modifying rainfall patterns, intensity and extremes; reducing snow cover and widespread melting of ice; and changing soil moisture, surface runoff, and stream discharge. This study analyzed impacts of future rainfall and air temperature patterns due to climate change upon hydrological processes in the Lower Yazoo River (LYRW), Mississippi using the US-EPA’s BASINS (Better Assessment Science Integrating Point and Non-point Sources)-HSPF (Hydrological Simulation Program-FORTRAN)-CAT (Climate Assessment Tool) modeling system. Several simulation scenarios were performed to investigate the impacts of different potential future rainfall rates and storm intensities as well as increasing air temperature trends upon surface water runoff, evapotranspiration, stream discharge, and water yield in the LYRW. A potential future wet and drought climate had discernable impacts on soil and stream hydrological processes. The BASINS-HSPF-CAT modeling system is a useful tool to modify historical weather data to project future climate change impacts on watershed hydrological processes.