Coupling Coordination Analysis Between Reclaimed Water Utilization Capacity and Effect in China

Reclaimed water utilization is one of the major strategies used to achieve sustainable development in China and for alleviating issues linked to insufficient water supply. This study leverages panel data encompassing 30 provinces in mainland China from 2011 to 2022 to establish a comprehensive evaluation index system for measuring the development level of reclaimed water utilization capacity and utilization effect. On the basis of this index, the development rule of coupling coordination between reclaimed water utilization capacity and utilization effect is explored using the coupling coordination degree model, Moran’s I index, and the grey GM (1,1) model. Experimental results show that the current utilization capacity and effect of reclaimed water in most provinces of China do not match. Moreover, China’s reclaimed water utilization capacity index was shown to gradually increase from 2011 to 2022. The reclaimed water utilization capacity index of the eastern region is significantly higher than the central region, which is lower than the national average, followed by the northeast region, and the western region obtains the lowest index. The calculation results of the coupling coordination model further demonstrate the coupling coordination degree between the reclaimed water utilization capacity; moreover, the effects of provinces and cities in China steadily increased, and there is a clear spatial clustering. The predicted results indicate that the abovementioned situation will likely continue until 2030. This study is anticipated to become a point of reference for relevant departments to optimize the coupling coordination degree of reclaimed water systems across different regions in China, implement differentiated measures, and promote a rational allocation of reclaimed water resources.