缺水地区城市河流健康评价研究——以太原市区9条河流为例

Health Assessment of Urban Rivers in Water Scarcity Areas:A case Study of Nine Rivers in Taiyuan City

构建缺水地区城市河流评价指标体系,丰富缺水城市水系管理、河流生态修复的理论基础。以太原市9条城市河流为研究对象,从水文水质、河流形态、生物、社会经济等4方面选取13个指标构建适用于缺水城市的河流健康指标体系,采用层次分析法和集对分析法进行评价。结果表明:9条河流均在过去5年里经历过大规模改造,各河流健康状态较为接近,其中,北排洪渠处于健康状态,风峪沙河处于不健康状态,其余7条河流处于亚健康状态;各河社会经济方面均处于健康状态,生物状况、河流形态多处于亚健康状态,水文水质多处于亚健康和不健康状态。评价结果从理论上揭示了太原9条河流存在的问题,水文状况较差是目前的主要问题,与实际情况较为一致,证明本研究所建立的评价模型适用于缺水地区城市河流健康评价。当前在河道尺度上开展生态补水是改善河流健康状态的主要手段和可行措施,而实施水源涵养、水资源优化配置、河道近自然恢复、海绵城市建设等流域综合治理修复是维持河流生态健康的治本之策。

Urban rivers in areas of water scarcity are characterized by small watersheds,seasonal inter-ruption of flow,weak ecological function,and poor landscape effect,which combine to give a health evaluation that is different from other urban rivers.In this study,nine urban rivers in Taiyuan city were selected for research,and we evaluated the health status of the rivers based on an urban river health eval-uation system developed for water scarcity areas.Our aim was to improve urban river health assessment methodology,theory and practice in areas of water scarcity,and to enrich the theoretical base for water system management and river ecological restoration in cities suffering from water scarcity.A total of 13 indicators from four aspects of river health(hydrology and water quality,morphology,biology,and so-cioeconomics)were selected for the construction of the river health assessment index system.The analyt-ic hierarchy process and set pair analysis were used to determine the weight of each index and the health status of each river was then evaluated.Five grades of river health were set in the system:very healthy,healthy,sub-healthy,unhealthy,very un-healthy.Results show that the health status of the nine rivers were relatively similar and all had undergone large-scale alterations in the past five years.Among the rivers,the Beipaihongqu River was healthy,the Fengyu River was unhealthy,and the other seven rivers were sub-healthy.All nine rivers were in a healthy state socioeconomically,but most were sub-healthy in terms of biology and river morphology,and sub-healthy/unhealthy in terms of hydrology and water quality.The evaluation reveals the existing problems for the nine rivers of Taiyuan,and indicate that,presently,poor hydrology is the primary problem.Results demonstrate that the evaluation system estab-lished in this study is suitable for the health evaluation of urban rivers in water shortage areas.Based on the health evaluation results for the nine rivers,measures to improve the river health were discussed and ecological water replenishment at river scale is the most feasible near-term measure for improving river health.In the longer term,comprehensive management and restoration of the basin are needed to im-prove river ecological health,including water conservation,optimal allocation of water resources,eco-logical restoration of rivers and city construction designed to retain water.