Abstract: Researching the characteristics of river sediment contamination and analyzing its ecological risks are of crucial importance to river regulation projects and to the controlling of secondary pollution. With the sediments detection results of Anrongjing River in Taizhou as a case study, we evaluated the heavy metal concentration, pollution state, spatial distribution, and ecological risks by analyzing single pollution index, potential ecological risk index, as well as cluster analysis. Results revealed that the sediments in Anrongjing River were severely contaminated with Cu, Zn, Pb, and Cd. In plane scale, pollution mainly concentrated in the upstream, the two tributaries, and the junction between tributaries and mainstream; in longitudinal sectional scale, the concentration of heavy metals declined with the deepening of sediments. Cu and Cd posed severe potential ecological risks, and also the pollution of Cd and Cu in the source, the two tributaries and the junction between tributaries and mainstream were the most serious.

Key words: river sediments, heavy metals, spatial distribution, ecological risk, Anrongjing River