Evolution and the drivers of water use efficiency in the water-deficient regions: a case study on Ω-shaped Region along the Yellow River, China.

Enhancement of water use efficiency (WUE) is considered highly important to cope with the water scarcity challenges in dry regions. Therefore, this study evaluated spatiotemporal characteristics of WUE and its related drivers in the Ω-shaped Region along the Yellow River aiming to provide decision support information for alleviating water shortages in this region. We employed the SBM-DEA (slacks-based measure-data envelopment analysis) model to calculate the WUE considering undesired outputs, analyze temporal and spatial variation based on GIS and statistical methods, and investigate the various factors that influence WUE based on the generalized method of moment (GMM) model. The results are as follows. (1) The WUE followed an increasing-decreasing-increasing trend, suggesting that the expanding agricultural and the second industrial structures are largely dominated by water-intensive activities which add further pressure on the water resources. (2) The spatial discrepancy of WUE among the cities is significant; however, the spatial pattern changes were stable during 2010 to 2019. (3) Analysis of influencing factors provides solutions for improving WUE in the Ω-shaped Region. Irrigation system and water conservancy infrastructure development and the acceleration of industrial transformation are necessary for improving the WUE in the Ω-shaped Region.