LI Yanyan, XU Dongyu, GAO Li and GAO Bo

Abstracts: At present, the eco-environmental problem in the Three Gorges Reservoir (TGR) area is highly concerned by government and people. The water-level fluctuation zone (WLFZ) is a significant component of ecological environment in the TGR. In recent decades, the heavy metal pollution in soils in WLFZ has attracted much attention from researchers all over the world. However, the comprehensive analysis on heavy metal pollution in soils in WLFZ remains scarce. Through literature review (the last ten years), this study summarizes the content, spatial and temporal distribution characteristics and ecological environmental risks of heavy metal in soils in WLFZ in TGR. The results show that in general, the concentrations of heavy metal in soils in WLFZ are higher in the upper and lower reaches than those in the middle reaches in the TGR. Meanwhile, the distribution characteristics of heavy metal vary with soil layer and elevation. Compared with soils before submergence, the metals concentration in soils in WLFZ exhibit dynamic change with the increase of dry/wet alternation cycle, and heavy metal in soils has the potential to transform into river water. The environmental risk assessment suggested that the studied soil generally belongs to the second-class soil, which is slightly polluted and shows slow ecological risk. The main heavy metals with ecological risks are Cd,followed by As and Hg. However,these metals do not influence human health at present. Finally, this review summarizes future research perspectives on the basis of current research status, which will provide a basis for the development of strategies to prevent soil heavy metal pollution in WLFZ and conserve water ecological environment in the TGR.

Keywords: Three Gorges Reservoir; water-level fluctuation zone; soil; heavy metal pollution; environmental risk; review