永定河系水生态空间异质性及治理策略研究

Study on Water Ecological Spatial Heterogeneity and Control Strategies of Yongding River System

永定河系是京津冀地区的重要生态廊道。2016年汛期和非汛期采集了永定河系21个采样点的水生态指标。监测结果表明,永定河系非汛期水质总体上劣于汛期。将NH3-N和COD两项水质指标的平均值做比较,非汛期比汛期分别升高了120.6%和278.1%。浮游植物以蓝藻门和硅藻门为主。采用层次聚类分析方法对永定河系水生态空间异质性进行了研究。研究结果表明,永定河系水生态存在明显的空间异质性,可划分为3个水生态分区:A区(桑干河)位于永定河系上游,是重要的产水汇水区域,经济以农业为主,面源污染相对突出;B区(洋河及永定河屈家店以上河段)由西北贯穿东南,穿越北京市区,是生态系统十分脆弱的区域;C区(永定河屈家店以下河段)是连接河流与近岸海域的特殊河段。针对不同分区的水生态特点,提出了相应治理与修复策略。

Yongding river system is an important ecological corridor in Beijing Tianjin Hebei region.In this paper,water ecological indexes of 21 sampling sites of Yongding River in flood season and non-flood season were collected.Monitoring results show that the water quality of non-flood season of Yongding river system was worse than that of flood season.Com pare the average value of NH3-N and COD,The value of non-flood season increased by 120.6%and 278.1%than that of the flood season.The main cyanobacteria were cyanobacteria and diatoms.Spatial heterogeneity of water ecosystem in Yong ding river system was studied by hierarchical cluster analysis.The results show that the Yongding River can be divided into three water ecological zones.District A was located in the upper reaches of the Yongding River,and also was an important water catchment area.The local economy was mainly agricultural,and non-point source pollution was relatively prominent.District B was from the northwest through the southeast,across the urban area of Beijing with a fragile ecosystem.District C was a special river connecting river and inshore waters.According to the water ecological characteristics of different dis tricts,the corresponding control and restoration strategies were put forward.