Assessing the site-specific impacts of climate change on hydrology, soil erosion and crop yields in the Loess Plateau of China

摘要

Climate changes may have great impacts on the fragile agro-ecosystems of the Loess Plateau of China, which is one of the most severely eroded regions in the world. We assessed the site-specific impacts of climate change during 2010–2039 on hydrology, soil loss and crop yields in Changwu tableland region in the Loess Plateau of China. Projections of four climate models (CCSR/NIES, CGCM2, CSIRO-Mk2 and HadCM3) under three emission scenarios (A2, B2 and GGa) were used. A simple spatiotemporal statistical method was used to downscale GCMs monthly grid outputs to station daily weather series. The WEPP (Water and Erosion Prediction Project) model was employed to simulate the responses of agro-ecosystems. Compared with the present climate, GCMs projected a −2.6 to 17.4% change for precipitation, 0.6 to 2.6°C and 0.6 to 1.7°C rises for maximum and minimum temperature, respectively. Under conventional tillage, WEPP predicted a change of 10 to 130% for runoff, −5 to 195% for soil loss, −17 to 25% for wheat yield, −2 to 39% for maize yield, −14 to 18% for plant transpiration, −8 to 13% for soil evaporation, and −6 to 9% for soil water reserve at two slopes during 2010–2039. However, compared with conventional tillage under the present climate, conservation tillage would change runoff by −34 to 71%, and decrease soil loss by 26 to 77% during 2010–2039, with other output variables being affected slightly. Overall, climate change would have significant impacts on agro-ecosystems, and adoption of conservation tillage has great potential to reduce the adverse effects of future climate changes on runoff and soil loss in this region.