08 June 2015

A Comparative Analysis of the Impacts of Climate Change and Irrigation on Land Surface and Subsurface Hydrology in the North China Plain

Summary

Climate change and human activities could induce environmental changes at the regional scale through altering land surface and subsurface states and fluxes. A team of scientists, including U.S. Department of Energy researchers at Pacific Northwest National Laboratory, investigated for the first time the effects of climate change and groundwater-fed irrigation on the land surface and subsurface hydrology in the North China Plain (NCP), one of the most vulnerable regions to climate change and human perturbations in China. Using three climate-change scenarios and one irrigation scenario, the team performed simulations using the Community Land Model 4.0. They found human water use tends to dominate the subsurface water balance in the NCP. Moreover, irrigation appears to have much larger effects on the top layer soil moisture whereas increase in precipitation associated with climate change exerts more influence on lower layer soil moisture. Groundwater exploitation, which removed a large amount of groundwater from the aquifer and applied it to the soil surface, has significantly altered the water availability and distribution in the NCP. This study highlights the importance of accurately accounting for the effects of human water use. The results provide insights to effective measures for adapting to environmental changes that are induced by climate change and human water use for this region.

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Acknowledgments

This work was supported by the National Natural Science Foundation of China (Grant No. 41171031), National Basic Research Program of China (Grant No. 2012CB955403), and Hundred Talents Program of the Chinese Academy of Sciences. M. Huang and L. R. Leung are supported by the U.S. Department of Energy Regional and Global Climate Modeling Program through the bilateral agreement between U.S. Department of Energy and China Ministry of Science and Technology on regional climate research. PNNL is operated for the US DOE by Battelle Memorial Institute under Contract DE-AC05-76RL01830. The authors thank two anonymous reviewers for their valuable comments that were helpful in improving this manuscript.