Impact of Climate Change on Streamflow and Soil Moisture in the Vermilion Basin, Illinois

Potential effects of climate change on streamflow and soil moisture in Vermilion basin, Illinois, are investigated using a spatial distributed hydrological model (WetSpa). The model results show good agreement between observed and simulated discharges at the Leonore gauge station and soil moisture at the Stelle soil moisture recording site. Climate scenarios are derived by statistical downscaling of regional climate predictor variables for two climate scenarios and four time periods. The downscaled local climate variables are used as inputs to the WetSpa model. The results of the hydrological simulations show that streamflow in the Vermilion basin may decrease substantially, especially in summer, as a result of less precipitation but primarily due to increased evapotranspiration. Predictions also indicate that reduced precipitation in summer combined with a substantial increase in evaporative demand may lead to soil moisture deficits in the fall, which could have a negative impact on the natural vegetation and rainfed crop growth. DOI: 10.1061/(ASCE)HE.1943-5584.0000546. (C) 2012 American Society of Civil Engineers.