城市河流栖息地评价方法与应用

Assessment of urban river habitats:application and methodology

维持河流生物完整性必须要有良好的栖息地条件.城市河流栖息地评价是城市河流治理和管理的前提和基础.城市河流栖息地评价基准与城市河流栖息地特征密切关联.基于可拓学物元概念和其发散性特征,以及前人的研究,建立了包含水质、形态结构、水动力和水生生物4个类别要素的适应于城市河流健康修复实践的栖息地质量评价指标体系,同时,结合层次分析法建立了多级可拓物元评价模型,并在评价过程中引入可拓学诊断方法以确定影响栖息地质量的关键因子.将以上方法应用于镇江市古运河,结合古运河修复目标和现状条件建立了相应的指标评价标准.经过1a多时间的野外调查,在古运河上选择6个500m长特征河段,分别对其栖息地、要素质量进行比较评价.结果表明,古运河整体栖息地及水质、水动力和水生生物质量均较差;诊断分析表明,水动力和水质为影响栖息地质量的主要因素,水质污染指数、透明度、流量满足率和纵向连续性为影响古运河栖息地质量的主要因子,并根据评价结果对古运河栖息地修复提出了建议.

A healthy habitat is essential for maintaining biological integrity. Assessment of urban river habitats （URH） provides a scientific basis for their restoration and management, and the criteria for assessment are closely related to the characteristics of URH. Based on the idea and the radiant quality of Matter-element, as well as former research, an index system for assessment of URH including water quality, morphology, hydrodynamics and aquatic biology, was set up to meet the objective of river restoration. Besides the combining hierarchy process method, multilevel extension assessment is discussed for assessment of URH, and the extension method for diagnosis is introduced. The above theory and method were applied to a case study of the Ancient Canal in Zhenjiang city, and homologous indicator criteria were established linking restoration objectives and the actual condition of the Ancient Canal. After conducting t^eld surveys for more than a year, 6 representative reaches were selected for assessment, and the results indicate that the general habitat quality, water quality, hydrodynamics and aquatic biology are in poor condition. Further diagnosis indicated the water quality and hydrodynamics are the main factors that affect habitat quality, and water quality, water transparency, guarantee rate of water demand and longitudinal connectivity are the key indexes. Finally, some suggestions for habitat restoration of the Ancient Canal are provided based on above results.