Projected hydrological changes in the North Carolina piedmont using bias-corrected North American Regional Climate Change Assessment Program (NARCCAP) data

Abstract

Study regionThe Haw River basin in the North Carolina Piedmont. Study focusSimulation of hydrologic change by projected CO2 and climate using the Soil and Water Assessment Tool (SWAT) hydrologic model. Biases of climate output from the North American Regional Climate Change Assessment Program (NARCCAP) were corrected using the LOCal Intensity (LOCI) scaling method for precipitation and Fourier functions for temperature. New hydrological insights for the regionEvapotranspiration (ET) and water yield (WY) with projected CO2, precipitation, and temperature during 2044–2070 were affected by each climate factor separately and synergistically. Increasing CO2 to 600ppm only scenario resulted in an ET decrease (5–17%) which led to WY increase (17–36%). With projected temperature increases (1–5°C) only scenarios, ET was projected to increase noticeably (12–112%) especially in winter and spring. The amount of projected ET increase was reduced by a CO2 increase to 600ppm due to decreased stomatal conductance. Projected WY varied due to the high variability of future precipitation patterns (−54% to 33%) but generally increased when solely precipitation projections were applied. However, WY with combined effects of CO2, precipitation, and temperature did not show significant changes compared with the historical WY. Therefore, it is necessary to incorporate interactions of precipitation, temperature, and CO2 to simulate future water availability in the North Carolina Piedmont.