【摘要】 依据南水北调中线干渠河南段10个采样点一年的水质监测数据，运用主成分分析法对中线干渠（河南段）水质时空变化进行分析。结果表明：南水北调中线干渠（河南段）水质总体上达国家Ⅱ类水质。从时间上看，中线工程干渠河南段水质处于中营养状态，且冬季水质要比其它季节好，属于Ⅱ类上乘水质，夏季水质最差,水体中氮、磷和其它有机物含量较高。从空间上看，南段为Ⅱ类上乘水质，离水源地越近，水质越好，北段水质最差。影响水质的关键自然因子从强到弱依次是水温、气温、月降水量、气压和PM10，其中，水温、气温、月降水量越高，水质越差，气压和PM10越大，水质反而越好。但在不同区段和不同季节影响因子的强度和方向又存在较大区别。污染物质主要是氮、磷和有机物。由于干渠两侧没有地表水注入干渠，所以干渠水质主要受水源地污染物、沿渠大气沉降和大气污染溶解的影响。建议加强水源地面源污染治理和干渠沿线大气污染防治，保证南水北调中线水质。更多还原

【Abstract】 Based on the data of 10 monitoring stations in the main canal of South-to-North Water Division Middle Route Project of Henan, the principal component analysis method is used to analyze the spatio-temporal variation of water quality in the middle route main channel(Henan section). The research results show that water quality of the channel meet the second-class water standard. On the spatial scale, water quality of the main channel of Middle Route Project in Henan section, and the water quality in winter is better than that in other seasons, belonging to Class Ⅱ superior water quality. The water quality in summer is the worst, and the content of nitrogen, phosphorus and other organic substances in the water body is high. From the perspective of space, the southern section is of Class Ⅱ superior water quality. The closer to the water source, the better the water quality is. The northern section is the worst. The key factors from strong to weak are water temperature, air temperature, monthly precipitation, air pressure and PM10, which influences water quality of the channel. The higher the water temperature, air temperature and monthly precipitation, the worse the water quality.The higher the air pressure and PM10, the better the water quality. However, those factors have different intensity and direction in different regions and different seasons. The main pollutants are nitrogen, phosphorus and organic matter. Since there is no surface water on both sides of the main canal flowing into the main canal, the water quality of the main canal is mainly affected by pollutants in the water source, atmospheric sedimentation along the canal and atmospheric pollution dissolution. It is suggested to strengthen the control of surface source pollution of water source and air pollution along the trunk canal to ensure the water quality of the middle route of South-to-North Water Diversion Project.更多还原