Dynamic Evaluation and Internal Driving Factors of Water Resources Green Efficiency in China

High-quality economic development and the realization of ecological civilization have become the main goals of China's economic development. This study constructed a global reference Malmquist-Luenberger productivity index model of directional distance function from the perspective of mixed disposability and divided water resources green efficiency into pure technical efficiency change (PEC) index, scale efficiency change (SEC) index, pure technology change (PTC) index and scale technology change (STC) index. The results show the following: (1) The value of China's water resources green efficiency increased by 1.1% from 2000 to 2016. The central region improved the most (1.4%), followed by the western (1%) and eastern (0.9%) regions. The water resources green efficiency improved in all provinces except Guangxi and Yunnan. (2) The water resources green efficiency is significantly affected by national policies, and there may not be a significant positive correlation with economic development. At present, the water resources green efficiency in most provinces still needs to be improved. (3) From 2000 to 2016, China's water resources green efficiency decomposition index showed an upward trend except for SEC, and PTC was the main driving force for improving China's water resources green efficiency. (4) The variation of PEC among provinces showed an inverted "N" trend, while the differences of SEC and STC showed an ascending trend, and PTC showed an inverted "U" trend. The proportions of provinces in which PEC, SEC, and STC indices improved were 40%, 46.67%, and 60%, respectively.