Water environmental efficiency in different urban spatial structure patterns: Evidence from a panel of Chinese urban districts

It is a major challenge of ecological sustainable development to seek ways to increase the utilization rate of water resources to maintain a particular economic growth. This dilemma can be effectively solved by adjusting the distribution of factors from a spatial perspective. However, rare empirical studies have explored the effect of the distribution adjustment on water environment efficiency from the urban spatial structure perspective. Thus, the aim of this study is to measure the spatial structure of urban districts from two dimensions, examine the water environmental efficiency of 156 urban districts in China between 2002 and 2016, and then primarily analyze the correlation between urban spatial structure and water environmental efficiency. The empirical study suggests that water environmental efficiency in most urban districts has increased in the study period, which is high in the eastern region and low in the central and western regions. The average value of water environmental efficiency has increased from 0.275 in 2002 to 0.406 in 2016. Moreover, urban districts more inclined to polycentricity achieve a higher water environmental efficiency on the full sample. Every increase of urban spatial centralization and concentration will increase water environmental efficiency by 0.005 and 0.303 units, respectively. However, impacted by the heterogeneity of urban districts, the weak-monocentricity is more effective in mega or high -densely urban districts. This study provides a reference for selecting a suitable spatial development pattern to increase the water environmental efficiency, and it takes on a significance in guiding the moderate agglomer-ation of the population and strengthening infrastructure construction.