Calculation of green water resources utilization efficiency in Jing-Jin-Ji urban agglomeration and analysis of its spatio-temporal differences and driving factors
Jing-Jin-Ji urban agglomeration is one of the areas with the most severe water shortages in China. Improving the utilization efficiency of green water resources is the only way to solve the contradiction between the supply and demand of water resources and realize the harmonious development of economy, society and ecology. Here, we measured the green water resources utilization efficiency of Jing-Jin-Ji urban agglomeration from 2008 to 2018 and analyzed its spatio-temporal differences using the Super-SBM model, with the consideration of unexpected output. And then the geographic detector model was used to explore the driving factors of green water resources utilization efficiency. The results show that the average utilization efficiency of green water resources did not reach the DEA effective state in Jing-Jin-Ji urban agglomeration, which was in an unstable state with fluctuations, and there was a big gap between the maximum and minimum efficiency of the urban agglomeration. The green water resources utilization efficiency varied greatly in different regions of the agglomeration, which was high in the northern region but low in the southern region, and the difference was increasing. Population size, industrial structure, natural resources and economic development had a significant driving effect on the improvement of the green water resources utilization efficiency in Jing-Jin-Ji urban agglomeration. The driving effect of urban openness had improved rapidly but was not stable; but that of the scientific and technological development level was always low and showed a downward trend.