Gu Xiao-Yun, Xu Zong-Xue, Liu Lin-Fei, Yin Xu-Wang, Wang Mi
Liaoning Provincial Key Laboratory for Hydrobiology, College of Fisheries and Life Science, Dalian Ocean University, Dalian 116023, China.
College of Water Sciences, Beijing Normal University, Beijing 100875, China.
Huan Jing Ke Xue. 2018 Jun 8;39(6):2576-2587. doi: 10.13227/j.hjkx.201706229.
With increasing urbanization, the stream ecosystem in Beijing has faced great challenges. Phytoplankton, benthic macroinvertebrates, and water quality were investigated based on 25 sampling sites in the North Canal River basin in July 2015, and the quality of the habitat was assessed in situ. A total of 22 metrics, including aquatic organism, hydrology, water quality, and habitat, were calculated to be the candidate indicators. A principal component analysis (PCA) and correlation analysis were used to select the core metrics from the candidate indicators, and the weight of each core metric was estimated by using the entropy method. The integrated index of stream ecological health was constructed to assess the health condition of the North Canal River basin. The results of the PCA and correlation analysis showed that nine metrics were selected as the core metrics to construct the integrated index of stream ecological health, i. e., the Shannon-Wiener diversity index of phytoplankton and benthic macroinvertebrates, water temperature, BOD, NH-N, F, Zn, petroleum, and the qualitative habitat evaluation index (QHEI). According to the results of the health assessment, 12% of the sampling sites in the North Canal River basin were considered to be healthy (Ⅰ) or sub-healthy (Ⅱ), and more than half were poor (Ⅳ) or bad (Ⅴ). Therefore, the aquatic ecosystem in the North Canal River basin was generally unhealthy. The upstream was better than the midstream and downstream, where the spatial heterogeneity of the health condition was strong. The health condition in the Nansha River, the midstream of the Qinghe River, and the main stream of the Tonghui River were poor, while the upstream of the Liangshui River and the tributaries of the Wenyu River were good. In general, the condition of the stream ecosystem in the North Canal River basin was relatively complicated.
随着城市化进程的加快，北京的河流生态系统面临着巨大挑战。2015年7月，基于北运河流域的25个采样点对浮游植物、底栖大型无脊椎动物和水质进行了调查，并对栖息地质量进行了现场评估。共计算了包括水生生物、水文、水质和栖息地在内的22个指标作为候选指标。采用主成分分析（PCA）和相关性分析从候选指标中筛选核心指标，并运用熵权法估算各核心指标的权重。构建河流生态健康综合指数以评估北运河流域的健康状况。主成分分析和相关性分析结果表明，选取了9个指标作为构建河流生态健康综合指数的核心指标，即浮游植物和底栖大型无脊椎动物的香农 - 维纳多样性指数、水温、生化需氧量、氨氮、氟、锌、石油和定性栖息地评价指数（QHEI）。根据健康评估结果，北运河流域12%的采样点被认为是健康（Ⅰ级）或亚健康（Ⅱ级），超过一半的采样点为较差（Ⅳ级）或差（Ⅴ级）。因此，北运河流域的水生生态系统总体不健康。上游状况优于中游和下游，健康状况的空间异质性较强。南沙河、清河中游和通惠河干流的健康状况较差，而凉水河上游和温榆河支流的健康状况较好。总体而言，北运河流域的河流生态系统状况较为复杂。
