A Transition Towards an Unusually Wet Condition Will Not Alleviate Water Scarcity Risk in Xinjiang, China

Abstract

The arid Xinjiang region of China exemplifies severe water scarcity regions with a burgeoning agriculture. Whether or not the ongoing wetting, unprecedented in instrumental hydroclimatic records, will become routine has implications for regional oasis economy and China's Go West plan. Here, we show that Xinjiang experienced a one-third increase in precipitation since the 1980s, and that this increase is primarily due to sea surface warming in the Bay of Bengal-west Pacific and tropical North Atlantic. Using the historical precipitation-sea surface temperature relationship to constrain future precipitation changes under a moderate warming scenario, annual precipitation over Xinjiang is projected to increase by 56% relative to the present-day, and the levels of wetness of exceptional years, such as 2010 and 2016, will potentially become a new norm in terms of regional mean within the next few decades. However, such a large precipitation-induced increase in freshwater resources will still be insufficient to rescue the Tarim and Junggar basins from their severe water scarcity dilemma within the next few decades, unless the most-efficient water-saving irrigation strategies are implemented.