Growing control of climate change on water scarcity alleviation over northern part of China

Study region: Northern part of China (NPC) Study focus: Along with rapid economic development and population growth, the NPC has been identified as a water scarcity hotspot. Previous studies attributed the intensified water scarcity primarily to increasing human water withdrawal over the NPC in the 20th century. However, water withdrawal has stagnated since the beginning of 21st century, which raises a question of whether the trend of water scarcity changes, particularly when considering the contribution of water availability that is subject to climate variability. Based on the water stress index (WSI), we detected the trends of water scarcity by a piecewise linear regression approach and investigated their associated drivers in the NPC by using survey-based datasets and hydro-climate model simulations. New hydrological insights for the region: Results show that the trends of WSI changed from positive to negative after 2001. Increased water withdrawal was the dominant factor for the aggravated water scarcity before 2001. However, as the rising precipitation offsets the effect of increasing evapotranspiration, climate change has increased water availability and become the major contributor to the alleviated water scarcity during 2001-2020. Furthermore, future projections suggest that climate change would further alleviate future water scarcity over the NPC by increasing water availability. The results suggest the growing role of climate change in affecting water scarcity, which are significant for guiding regional water policy-making.