Hydrological response to climate change in the Black Hills of South Dakota, USA

The hydrological response due to potential CO2-forced climate change in the Black Hills of South Dakota was investigated using modelling techniques th at include variations to atmospheric CO2, temperature, and precipitation. T he soil and Water Assessment Tool (SWAT) was used to model the 427 km(2) Sp ring Creek basin hydrology and simulate the impact of potential climate cha nge. As expected, modelling results of precipitation and temperature change demonstrated that increased temperature caused a decrease in water yield w hile increased precipitation caused an increase in water yield. Increased C O2 and precipitation caused the largest increase in yield. Modelling result s of increased atmospheric CO2 indicate that average annual water yield inc reased by 16%. The increase is attributed to a suppression of transpiration processes due to increased level of atmospheric CO2. Simulation results de monstrate that increased concentrations of atmospheric CO2 act to dampen wa ter yield loss due to the effects of increased temperature or decreased pre cipitation alone.