Distribution features and ecological risk assessment of heavy metals in surface sediments of Wuliangsuhai Lake
乌梁素海表层沉积物重金属分布特征及生态风险评价

The surface sediments of Cu,Zn,Pb,Cr,Cd,Hg and As were sampled and analyzed in order to get better understanding on the concentration and distribution of heavy metals in Wuliangsuhai Lake.The method of potential ecological risk(PER)index presented by Lars Hakanson was applied to analyze the accumulation coefficients,PER coefficients and the PER indexes of the seven kinds of heavy metals based on the normal grain of modern pre-industrial levels of heavy metals background values and the highest loop background values of heavy metal content in soil respectively.The results showed that there was large spatial variability of As and Pb in the surface sediments.The similar sequence of the contaminative level was obtained based on the two background values,Hg and As had the most potential impact on the ecological environment.It also showed that the background values of Hetao more directly reflected the level of heavy metals in the surface sediments of Wuliangsuhai Lake.