Water shortages raised a legitimate concern over the sustainable development of the drylands of northern China: Evidence from the water stress index.

Developing a greater understanding of water stress dynamics is crucial for sustainable development in global drylands. The primary goal of this study was to examine the water stress dynamics throughout the drylands of northern China (DNC). We first calculated the water stress index (WSI) of all 474 catchments in the DNC in 2003 and 2014. Then, we investigated the water stress dynamics in the DNC between 2003 and 2014 at multiple scales, which included the entire DNC, the drainage basins, and the main cities. In 2014, we found water stress in DNC over an area of 2.05×106km2, which accounted for 52.13% of the total area of the DNC. From 2003 to 2014, the water stress in the DNC increased primarily because of increases in the area of irrigated croplands and the population of urban areas, and the total increase in the water stress area reached 3.14×105km2, which accounted for 7.98% of the total area of the DNC. We also found that water shortages raised a legitimate concern over the sustainable development of the DNC because the population and urban land area exposed to water stress in the DNC have rapidly increased by 2.61×107 persons and 1.25×104km2 over the past two decades, respectively. Thus, we argue that effective actions are required to address the water stress in the DNC.