Factor analysis and dynamics of water quality of the Songhua River, Northeast China

The water quality of the Songhua River (Northeast China) was of concern, especially in the 1980s and early 1990s, and there were many studies carried out on this aspect. However, only one or several independent water quality indices were used to consider the effects of pollutants on the water quality, for instance, heavy metal and toxic organic pollutants. The combined effects of multiple indices were seldom studied. In this article, based on the environmental monitoring data, the water quality of the Songhua River was analyzed using factor analysis, which comprehensively considered six indices of water quality of each monitoring section. The results showed that the main pollutants had changed to nitrogenous pollutants originated from nonpoint sources, and water quality was variable in different hydrological periods. The results also showed that the method was comprehensive and efficient in analyzing the dynamics of water quality.