Abstract: To find out the surface water quality in Xi-xian New Area, we monitored the water quality in three rivers in this area for two years. And we used cluster analysis, discriminant analysis, and factor analysis to examine the spatial and temporal distributions of pollutants and their variations in the study area, along with an analysis of the pollution sources. The results show that the nitrogen and phosphorus pollution is severe in the monitored river sections, with the total nitrogen (TN) exceeding the Class IV surface water quality standard level by 7.62 times, total phosphorus (TP) by 3.60 times, and ammoniacal nitrogen (NH3-N) by 1.89 times. Cluster analysis shows the water quality falls into three categories in different seasons: wet season of June through October, normal season of March through May, and dry season of November through February. Spatially, it falls into two categories, one cluster for the water quality in the Weihe River and the Fenghe River, and the other for the Xinhe River. Water pollution in the monitored river sections is greatly influenced by the quality of their upstream inflow. In the mainstream Weihe, the major pollution sources are the domestic sewage, industrial wastewater, and agricultural non-point pollutants discharged in its upstream regions; Fenghe’s major pollution source is agricultural pollutants; Xinhe’s pollutants largely come from anthropogenic pollution.

Key words: water environment, Weihe River, Xi-xian New Area, multivariate statistical analysis, water quality evaluation