基于层次聚类和水质指数法的南水北调中线总干渠典型年份水质变化特征分析OA北大核心CSTPCD

In order to investigate the characteristics and spatiotemporal differentiation of water quality in the middle route of the South-to-North Water Diversion project.The monthly monitoring data of 10 water quality indexes in 30 sections of the main canal in typical years were selected,and the variation of water quality was analyzed by hierarchical clustering and WQI water quality index method.The main canal was divided into 3 types of water quality canal segments by hierarchical clustering.The 24 sections from Taocha to Liujiazuo were the first section,and the concentration of water quality indexes in this section was relatively low,the indexes of F.coli((44.41±56.11)colonies·L-1),CODMn((1.94±0.11)mg·L-1),SO42-((29.38±1.68)mg·L-1)and DO((9.74±1.42)mg·L-1)were lower than those of other canals.Bazhou,Wangqingtuo,Xiheishan,Huinanzhuang and Tuancheng Lake were the second type of canals.Compared with the first type of canals,the concentrations of water quality indexes such as F.coli((184.5±323.16)colonies·L-1),CODMn((2.08±0.29)mg·L-1),SO42-((27.21±1.81)mg·L-1)and DO((10.82±2.15)mg·L-1)increased.Tianjin Waihuan River is the third type of canal section,and the concentrations of TN,NH3-N and BOD5 in this section reached the maximum values,which were((1.32±0.15)mg·L-1),((0.07±0.05)mg·L-1)and((1.52±0.51)mg·L-1),respectively.The results of WQI calculation showed that,the average value of WQI was between 81 and 86,and the water quality was good.The mean value of WQI in summer was the lowest(81),lower than that in spring(84),autumn(83)and winter(84),and the mean value of WQI gradually decreased along the way.The research results can provide theoretical basis for water quality protection and management of the Middle Route Project.