Status Quo and Evaluation of the Spatial Distribution of Heavy Metals in Urban Soil of Qingdao City

Spatial distributions of eight heavy metals( As,Cd,Cr,Cu,Hg,Ni,Pb and Zn) in the top soil in Qingdao city were analyzed by means of the ordinary Kriging,and accumulation of the heavy metals in the soil assessed with the single factor index and Nemerow index methods. Results show that the eight heavy metals are significantly anisotropic in spatial variability,on the whole,displaying a decreasing trend from the northeast to southwest. The proportion of the soil samples showing obvious accumulation as affected by heavy metals contamination is quite low,being 4. 7%,and the soil environment quality in general is good. The contents of Zn,Hg,Cd,Cr and Cu in some soil samples around traffic hubs and in the industrial zones and living quarters are over Grade Ⅲ criteria of the National Standard for Soil Environment Quality. The findings of the study may serve as reference for decision making in urban environmental planning and management,and urban soil remediation.