天津市河流生态完整性评价

对河流生态健康状况进行评价，可为河流治理和生态修复提供依据.基于2018年8—9月天津市河流现场调查获取的物理、化学和生物群落指标（浮游动物、浮游植物、底栖动物、鱼类、水生大型植物、陆生植物）数据，构建包含物理完整性、化学完整性和生物完整性在内的河流IEI（index of ecological integrity，生态完整性指数）评价体系，对天津市河流生态健康状况进行评价.根据生物栖息地评分和水质状况确定参照点位，采用标准化方法筛选候选指标，应用层次分析法计算三部分指标权重，最终得出天津市河流生态健康评价结果.结果表明:①IEI评价结果显示，天津市河流生态健康状况等级为“健康”的样点占18.8%，“较好”的样点占28.1%，“一般”的样点占40.6%，“较差”的样点占6.3%，“差”的样点占6.3%，天津市河流生态健康状况整体处于“一般”水平.②相关性分析表明，ρ（NH₄+-N）和ρ（COD_Mn）超标是造成天津市水质达不到功能区标准的主要原因，同时也是影响河流生态健康的主要因素.研究显示，IEI评价法能够较为敏感地响应研究区面临的环境压力，适用于评价研究区河流生态健康. 

Assessment of Ecological Integrity of Rivers in Tianjin City

Ecological health assessment of rivers can provide a basis for river management and ecological restoration. Based on the survey data of physical, chemical and biological community indicators (plankton, phytoplankton, benthic, fish, aquatic large plants, terrestrial plants) from August to September 2018, an index of ecological integrity (IEI) evaluation system including physical integrity, chemical integrity and biological integrity was established to evaluate the ecological health of rivers in Tianjin City. The reference points were determined based on the biological habitat scores and water quality conditions, and standardized methods were used to screen candidate indicators. The analytic hierarchy process was used to calculate the weights of the three parts of indicators, and the Tianjin City river health assessment results were finally obtained. The results showed that:(1) The IEI evaluation results showed that 'healthy' samples accounted for 18.8%; 'good' samples accounted for 28.1%; 'general' samples accounted for 40.6%; 'worse' samples accounted for 6.3%; 'poor' samples accounted for 6.3%, and the ecological health status of rivers in Tianjin City was at a general level. (2) Correlation analysis showed that high concentrations of NH₄+-N and COD_Mn were the main cause of the poor water quality cannot reach functional zone standard in Tianjin City, and also the main factors affecting the ecological health of the rivers. The results show that IEI can respond more sensitively to the environmental pressures faced by the study area and is suitable for evaluating the ecological health of the rivers in the study area.