长江经济带水资源绿色效率时空演变特征及其影响因素

长江经济带是中国重要的水资源聚集区、水生态功能区,其水资源绿色效率问题直接影响了生态系统质量和稳定性。本文从高质量发展视角,构建了长江经济带110个城市水资源绿色效率评价指标体系,采用定基极差熵权法、超效率EBM模型和GML生产率指数以及空间面板分位数回归等计量方法,对水资源绿色效率的时空演变特征及其影响因素等问题进行测度与识别。结果表明：①从时序演变来看,2005—2018年长江经济带水资源绿色效率总体水平呈高低交错状的波动上升趋势,先后经历了“稳增期”“振落期”“提速期”等3个阶段。②从空间格局来看,长江经济带水资源绿色效率空间分异特征显著,水资源绿色效率较高的地区主要是经济发达的中心或副中心城市,数值较低的城市大多集聚在中、上游经济不发达地区,表现出由高向低的扩散迹象,且在全局空间检验中发现存在正的自相关性,局部空间存在集聚现象和溢出效应。③从影响因素来看,产业结构、经济发展水平、资源禀赋、科学技术水平、政府管制力度以及对外贸易程度对水资源绿色效率均有显著影响,但在不同分位点下的水资源绿色效率,其驱动因素的影响方向与力度均有差异,该结论在一系列稳健性检验之后仍旧成立。最后,根据长江经济带水资源绿色效率时空演变趋势和规律,有针对性地提出了相关政策建议。

Spatiotemporal pattern and influencing factors of green efficiency of water resources in the Yangtze River Economic Belt

The Yangtze River Economic Belt is an important water resources gathering area and water ecological functional area in China, and its green efficiency of water resources directly affects the quality and the stability of the ecosystem. From the perspective of high-quality development, this paper reconstructs the green efficiency evaluation index system of water resources in the Yangtze River Economic Belt. Then, we measure and identify the characteristics of the spatiotemporal pattern and influencing factors of the green efficiency of water resources by using the method of fixed base range entropy weight, the super-efficiency EBM model, GML productivity index and the quantitative regression of spatial panel data model. The results shows that: (1) From the evolution of time sequence, the overall green efficiency of water resources in the Yangtze River Economic Belt from 2005 to 2018 shows a fluctuant upward tendency taken on the high and low staggered form, which successively experiences three stages: “steady increase period”, “vibration period”, and “speed-up period”. (2) From the perspective of spatial pattern, the spatial difference of green efficiency of water resources in the Yangtze River Economic Belt is remarkable. The area with higher green efficiency of water resources are mainly economically developed central or sub-central cities, as the cities with low level gathers in the middle reaches and upstream underdeveloped regions, which shows the sign of proliferation from high to low. And there is a positive autocorrelation in global spatial testing. Meanwhile, the agglomeration phenomenon and spillover effect are been discovered in the local space. (3) From the perspective of driving factors, industrial structure, economic development level, resources endowment, science and technology level, government regulation and the degree of foreign trade all have a significant impact on the green efficiency of water resources. However, for the green efficiency of water resources at different quantiles, the driving factors have different effect on directions and strengths, which is still valid after a series of robustness tests. Finally, according to the trend and law of spatial and temporal of the green efficiency of water resources in the Yangtze River Economic Belt, the relevant policy recommendations are put forward.