Exploratory analysis on spatio-seasonal variation patterns of hydro-chemistry in the upper Yangtze River basin

Identifying the spatio-seasonal variation patterns of hydro-chemistry and their influencing factors plays an important role in efficient water environment management. This study conducted exploratory analysis in the upper Yangtze River basin (UYRB) based on the monthly monitoring data concerning 20 hydro-chemical parameters and 12 sampling stations, using the multivariate statistical techniques including cluster analysis (CA) and factor analysis/principal component analysis (FA/PCA). Field investigation on the residential and industrial activities was performed to assist and verify the pattern recognition and pollutant source identification. An inter-comparison with related works revealed that environmental capacity, relative up-/down-stream location and anthropogenic activities were three critical factors influencing the spatial heterogeneity of water quality. The active anthropogenic practices together with the increased surface runoff accounted for the deteriorated water quality in wet season (May-Oct.) in UYRB. The spatio-seasonal variation patterns generalized and research prospects proposed in the present study could provide a comprehensive insight and systematic supports to future works.

Automated summary

The study identified that environmental capacity, relative position, and anthropogenic activities were critical factors influencing water quality in the upper Yangtze River basin, with deteriorated water quality in the wet season attributed to increased anthropogenic practices and surface runoff. The spatio-seasonal variation patterns and research prospects proposed in the study could offer comprehensive insights and systematic supports for future works.