Quantitative analysis of spatiotemporal disparity of urban water use efficiency and its driving factors in the Yangtze River Economic Belt, China

Study region: Yangtze River Economic Belt, China Study focus: As the major national strategic development area of China, there have always been vital problems about imbalance of the water resources distribution and the disparity of economic levels in YREB. Quantitative analysis of water use efficiency (WUE) is essential to the rational use of water resources, as well as the sustainable development. In this study, a WUE evaluation index system for prefecture-level cities in the YREB was constructed, and Super-Efficiency Data envelopment analysis Slacks-Based Measure (DEA-SBM) model, Global Malmquist-Luenberger productivity index, combined with geographically weighted regression model were utilized to measure and identify the spatiotemporal evolution characteristics of WUE and its influencing factors. New hydrological insights for the region: From the temporal perspective, the WUE manifests a significant upward trend from 2005 to 2020, and the growth presents lower reach > middle reach > upper reach; in the spatial pattern, the WUE has significant spatial divergence characteristics, high WUE mainly occurred in developed leading cities, while developing cities in the midstream and upstream tended to be inefficient; various effects on WUE were also analyzed, highlighting that technical advancement was the key driver of WUE evolution. Then the negative effects of industrial structure and urban environment was becoming more and more significant. Finally, effective measures for upstream, middle and downstream cities in the YREB were discussed.