Aim : Methodology :Results : Interpretation :In this study, statistical methods and visualization were used to study the distribution of heavy metals and the potential hazards to the aquatic ecosystem along the main waterway of the Le'An Basin. This waterway has been severely polluted with heavy metals as a result of mining activities.A total of 22 surface sediment samples were collected from sampling sites in four typical areas representing the entire Le'An river. We compared the measured results to the background values. The geo-accumulation index (I ), integrated pollution load index (PLI) and sediment quality standard combined with statistical methods were used to assess the degree of pollution, their potential sources and ecosystem risk level.Sites near Shanggukou Bridge and downstream of the intersection of the Le'An and Jishui Rivers had the highest pollution levels of Cu, Zn, Cd and As. In addition to the background areas (BA), both I values and PLI indicated that all the sites were class 4, 5 and 6 types. Upstream areas (UA) and middle stream areas (MA) were considered to be highly polluted. Based on the geochemical partitioning analysis and the ratios between secondary phase and primary phase values, the results revealed that higher concentrations of Cu, Pb, Cd andAs in the UA and MAwere likely to be harmful to the aquatic organisms in these areas. Principal Component Analysis (PCA) and Hierarchical Cluster Analyses (HCA) revealed that Cu, Zn, Pb, Cd, Cr andAs were sourced from many complicated anthropogenic sources.Metallic discharges from non-ferrous mine plants and township enterprises contributed the largest portion of sediment pollutants. The visualization technique of Chernoff faces were useful for representing and interpreting the multidimensional data. jiyong@nit.edu.cn Publication InfoPaper

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