08 May 2015

Projected Changes in Mean and Interannual Variability of Surface Water over Continental China

Summary

Climate warming is projected to increase rainfall variability and substantially intensify the global water cycle, with notable effects on the water availability for ecosystems and agriculture. Most Asian countries are facing challenges in adapting to social and environmental problems associated with climate change. China is one of the most vulnerable countries around the world, with water being one of the sectors most directly affected. A team of scientists, including U.S. Department of Energy researchers at Pacific Northwest National Laboratory, examined the projected changes of surface water across China using climatic variables from the Fifth Assessment Report of the Intergovernmental Panel on Climate Change to provide up-to-date knowledge of future water resources distributions in China. The team found larger fractional changes of annual mean evapotranspiration per unit warming than the corresponding fractional changes of precipitation per unit warming across the country, especially for South China, which led to a notable decrease of surface water variability. Interannual variability for both runoff and soil moisture becomes more pronounced for almost all river basins across China. They found that future climate change could further exacerbate existing floods and droughts across China, as indicated by the marked decrease of surface water amounts combined with more frequent floods and droughts throughout the 21st century. Spatially, surface water availability was projected to decrease by the end of the 21st century, especially for South China, even though the same regions experienced increases in precipitation. By providing regional analysis and comparison across all river basins in China, this study highlights important differences in hydrologic responses between South China and North China to climate change at various temporal scales.

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Publications
2015.  "Projected Changes in Mean and Interannual Variability of Surface Water over Continental China."  Science China Earth Sciences, doi:10.1007/s11430-014-4987-0.
Acknowledgments

The careful reviews and constructive comments/suggestions from two anonymous reviewers are gratefully acknowledged. 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. This work has been conducted under the framework of ISI-MIP. The ISIMIP Fast Track Project was funded by the German Federal Ministry of Education and Research (BMBF) (Grant No. 01LS1201A). Responsibility for the content of this publication lies with the authors. M Huang and LR Leung are supported by Office of Science of the U.S. Department of Energy through the Regional and Global Climate Modeling Program. PNNL is operated for the US DOE by Battelle Memorial Institute (Grant No. DE-AC05-76RL01830).