Spatial-temporal differentiation and driving factors of water resources green efficiency in the Huaihe River Basin

Considering the regional economic and social characteristics and high-quality development goals, this paper improves the calculation method of green efficiency of water resources and adopts the SBM-DEA model to calculate the green efficiency of water resources in 35 cities of 4 provinces in the Huaihe River Basin. The results show that (1) the green efficiency of water resources in the Huaihe River Basin decreased first and then increased from 2011 to 2020. (2) In terms of spatial distribution, the provincial-level divisions of green efficiency of water resources in the Huaihe River Basin from high to low are Shandong, Henan, Jiangsu, and Anhui. The elliptical area of green efficiency of water resources keeps expanding, and the efficiency value radiates outward along Yangzhou-Zhengzhou'. (3) At the level of total-factor productivity decomposition, TC (technological change) has a more noticeable impact on factors than EC (efficiency change). TC scale technology changes mainly come from the improvement of MATC (magnitude technical change). (4) Industrial output value has a positive driving effect on the green efficiency of water resources. Government participation, resource endowment, and economic growth rate reflect China's current incongruity between economic development and water resources green efficiency improvement.