Soil Heavy Content Analysis and Ecological Risk Assessment of Different Landuse Types in Daqing Region

Compared to soil heavy metal values as 75 period of Daqing city,soil background values of Heilongjiang province and the state soil environment quality standards,the content rules of ten soil heavy metals in different landuse types were analyzed by using contrast analysis method,and the assessment of ecological risk was also studied.The results showed that the contents of soil As,Zn,Hg and Pb were the highest in industrial land,and the contents of soil Cd,Cr,Cu,Ni,Mn and V were the highest in dry land.The soil heavy metal contents of grassland,unused land and paddy field were lower than others.Compared to soil heavy metal values as 75 period of Daqing city,the contents of rest soil heavy metals were increasing except soil V.The contents of soil Hg,As and Cd increased to a larger extent,and Hg pollution should be paid close attention to soil especially.The compound pollutions existed in soil heavy metals,and the correlations of pH value and soil heavy metals were not significant,but soil heavy metals and organic matter,CEC related significantly.The content of Hg of industrial land arrived to serious ecological harm degree from Ei value analysis.Ei values of soil Cd were larger in five landuse types and dry land largest.RI value order of soil heavy metal in five different landuse types was industrial landdry landpaddy fieldgrasslandunused land.Industrial land belonged to the degree of extreme potential ecological harm,and other landuses were the degree of mild potential ecological harm.