Temporal-spatial patterns and coupling coordination degree of water resources carrying capacity of urban agglomeration in the middle reaches of the Yangtze River

长江中游城市群是实施生态优先绿色发展战略的重点区域，从水资源承载系统内的水资源、社会、经济、生态环境4个子系统中选取24项指标构建水资源承载力评价体系，综合运用改进熵权TOPSIS模型、空间自相关分析和耦合协调发展模型定量评价2012-2018年长江中游城市群水资源承载力时空变化过程及子系统间的耦合协调性.结果表明，（1）长江中游城市群整体水资源承载力水平表现为：缓慢上升（2012-2015年）、下降（2015-2017年）、再上升的趋势（2017-2018年）；（2）水资源承载力的空间差异不明显（仅2016年差异显著），武汉城市圈水资源承载力的空间差异相对较大且呈现低值包围高值的空间分布特征；（3）各城市生态环境子系统承载力得分较为均衡，但其他子系统的承载力均差异较大；（4）影响水资源承载力的主要因素依次为城市污水处理厂日处理能力、人均GDP、城镇化率、第三产业比重和人均水资源量；（5）长江中游城市群水资源承载系统的耦合协调度总体处于中等水平，且水资源承载力与耦合协调度有极强的正相关关系.研究结果可为长江中游城市群水资源承载力改善及水资源优化配置提供依据.;The urban agglomeration in the middle reaches of the Yangtze River is a key area for implement the ecological priority green development strategy. This study selects 24 indicators from water resources subsystem, social subsystem, economic subsystem, and eco-environmental subsystem of the water resources carrying systemto construct a water resources carrying capacity evaluation system. The improved entropy weight TOPSIS model, spatial autocorrelation analysis and coupling coordination model are used to quantitatively evaluate the spatiotemporal process of water resources carrying capacity and the coupling coordination degree of the four subsystems in urban agglomeration in the middle reaches of the Yangtze River from 2012 to 2018. The results showed that, (1) The overall water resources carrying capacity of the urban agglomeration in the middle reaches of the Yangtze River shows a trend of slow increase (2012-2015), decrease (2015-2017), and rise again (2017-2018); (2) The spatial difference of water resources carrying capacity is not obvious (only behaving significant differences in 2016). The spatial difference of water resources carrying capacity of Wuhan Metropolitan Area is relatively significant and is characteristic of the spatial distribution characteristics of low values surrounding high values. (3) The carrying capacity of the eco-environmental subsystem of each city is relatively balanced, but the carrying capacity of other subsystems are quite different. (4) The main factors affecting the carrying capacity of water resources are daily treatment capacity of municipal wastewater treatment plants, GDP per capita, urbanization rate, proportion of tertiary industry and water resources per capita. (5) The coupling and coordination of water resources carrying systems in study area is generally at a medium moderate level, and water resources carrying capacity is positive correlation with the (degree of) coupling coordination. The research results can provide a basis ground for the improvement of water resources carrying capacity and the optimal allocation of water resources in the urban agglomeration in the middle reaches of the Yangtze River.