水源供给服务供需流空间不匹配特征识别及优化

如何识别水源供给服务在自然-人类社会系统中的空间流动过程和匹配特征,对于区域水资源管理和可持续利用具有重要意义。以重庆市为研究区域,基于InVEST模型和社会经济发展视角定量评估流域尺度下的水源供给量和需水量,结合水资源安全指数和热点分析构建水源供给服务流模型,揭示水源供给服务供需空间匹配关系,依据水源供给服务流空间属性特征划分供需匹配关系的区域类型,借助地理探测器从自然、社会和生态三个角度讨论影响各区域类型水源供给服务供需匹配关系的影响因素。结果表明:(1) 2000、2010、2020年重庆市流域水源供给量与需水量均先减少后上升,供需比平均值分别为1.17、1.08、0.9,整体供需不匹配的问题逐渐得到缓解,但局部仍有供需不匹配现象。空间上中高度赤字区域集中在主城区内,向外辐射为轻度赤字区域,盈余区域分布在东北和东南方向。(2) 2000、2010、2020年重庆市水源供需比冷、热点范围均在缩小,流域面积分别相对减少了25.34%、9.2%。水源供给服务流空间上整体呈现出自东北、东南方向向西流动的路径,同时冷点区内部呈边缘向中心流动。(3) 汇流区集中在西北部,经流区位于中部,外流区集中在东南和与东北部。影响汇流区供需匹配关系的主导因素是蒸散发,解释力为74.08%;影响经流区的主导因素是第三产业GDP,解释力为51.44%;外流区各影响因子的解释力均较低。不同影响因子之间蒸散发与其它因素的交互作用显著增强。研究可以为重庆市自然资源的管理与流域生态补偿机制的建立提供科学依据。

Identification and optimization of spatial mismatch characteristics of supply and demand flows for water supply services

How to identify the spatial flow processes and matching characteristics of water supply services in natural-human social systems is important for regional water resources management and sustainable utilization. Taking Chongqing as the study area, the water supply and water demand at the watershed scale in Chongqing from 2000 to 2020 were quantitatively assessed based on the InVEST model and socio-economic development perspective. Combining the water security index and hotspot analysis to build a water supply service flow model, we reveal the spatial matching relationship between supply and demand of water supply services, and classify the regional types of supply and demand matching relationship based on the spatial attribute characteristics of water supply service flow. On this basis, the factors influencing the matching relationship between supply and demand of water supply services for each regional type are discussed from three perspectives: natural, social and ecological with the use of the Geodetector. The results show that (1) From 2000 to 2020, the supply and demand of water in the Chongqing watershed first decreased and then increased, and the average value of the supply-demand ratio was 1.17, 1.08, and 0.9, respectively. Overall supply-demand mismatch gradually easing, but localized mismatch still exists. The areas of medium to high spatial deficit are concentrated within the main urban area, radiating outwards into areas of mild deficit, and the surplus areas are distributed in the north-eastern and south-eastern directions. (2) From 2000 to 2020, the cold and hot spot range of water supply and demand ratios was shrunk in Chongqing, and the watershed area was relatively reduced by 25.34% and 9.2%, respectively. The water supply service flow spatially showed an overall flow path from the northeast and southeast to the west, while the cold spot area presented edge-to-center flow within the area. (3) The confluence area was concentrated in the northwest, the meridian area was located in the middle, and the outflow area was concentrated in the southeast and the northeast. The dominant factor affecting the supply-demand matching relationship in the confluence area is evapotranspiration, with an explanatory power of 74.08%; the dominant factor affecting the meridional area is the tertiary GDP, with an explanatory power of 51.44%; the explanatory power of all influencing factors in the outflow area is low. Interaction of evapotranspiration with other factors was significantly higher among different impact factors. The study can provide a scientific basis for the management of natural resources and the establishment of watershed ecological compensation mechanisms in Chongqing.