流域水环境承载力聚类分区方法研究——以湟水流域小峡桥断面上游为例

流域内社会经济发展水平与水资源环境条件存在空间差异,导致水环境承载力具有空间差异特征.因此,有必要在流域水环境承载力分区基础上,实施差异化监管.以湟水河流域小峡桥监测断面上游为例,基于国家控制单元划分16个子单元,从水环境承载力大小、水环境承载状态、水系统脆弱程度及水环境承载力开发利用潜力4个角度,构建水环境承载力聚类分区指标体系,并对其进行量化.在此基础上,利用k-均值聚类法对控制子单元进行合并分区.通过轮廓系数验证,将研究区划分为4类最合理,即重点保护水环境敏感区、限制开发水资源约束区、控制开发水环境超载区和优化开发高开发潜力区.针对不同分区特点,提出具有针对性的水环境承载力双向调控措施,为流域水系统精细化管理及可持续发展提供科学依据.

A study on the clustering zoning method for water environmental carrying capacity in the watershed scale: Analysis exploring the upstream areas of Xiaoxia Bridge Section in Huangshui River Basin

There are spatial differences in social and economic development,water resources and environmental conditions in the basin,leading to different spatial water environmental carrying capacity.It is therefore necessary to implement effective differentiated strategies based on the regional differences in water carrying capacity.In this paper, upstream areas of Xiaoxia Bridge Section in Huangshui River Basin were selected as the study areas and were divided into 16 subareas based on the national control units.An index system was established for clustering the zoning considering four perspectives of carrying capacity,carrying status,vulnerability of water system and exploitation and utilization potential.The k-means algorithm was used to combine control subunits based on the four quantified integrated indicators.The results indicated that an optimal clustering number of 4 was obtained by calculating the silhouette coefficient,including key protective area characterized by sensitive water environment,restricted development area characterized by water resources restriction,controlled development area characterized by overloaded water environment,and optimized development area characterized by high exploitation and utilization potential.The suggestions on the corresponding bidirectional regulation to four different subareas are also put forward to provide a scientific reference to elaborate management and sustainable development of water system in the basin.