Spatial Distribution and Soil Pollution Risk Evaluation of Soil Heavy Metals Content Based on Geostatistics
A large number of soil heavy metal content data and spatial data were obtained through soil survey and laboratory analysis.Spatial variability of soil heavy metals were analyzed by ordinary Kriging (OK) and classical statistical analysis.The pollution risks of each soil heavy metals were studied by utilizing indicator Kriging (IK) and the integrated risk of soil pollution was calculated by multiple variable indicator Kriging (MVIK).Results showed that the contents of heavy metals of As,Cd,Cr,Cu,Pb,Hg,Ni and Zn in karst area were obviously higher than those in non-karst area.They were significantly correlated with each other (p ＜ 0.01),meaning that they were of the same source.The value of correlation coefficient between Zn and Cd was the highest,and the value of correlation coefficient between As and Cd was the lowest.All the soil heavy metals had significant correlations with pH values (p ＜ 0.01).All the heavy metals had strong spatial variability with exception of Cu,due to the intrinsic factors,including the lithology and soil forming rock.The high values of heavy metals were in the southeast and north of the survey area,and the low values were in the southwest area.There were pollution risks for As,Cd,Cr,Cu,Pb,Hg,Ni and Zn,and the risk probabilities of them were 0.326,0.805,0.185,0.192,0.267 and 0.270,respectively.Therefore,there was high pollution risk for Cd.The probability for integrated risk of soil heavy metals pollution was 0.335.The study provided scientific consults for the industrial and agricultural production and the environment management.
soil heavy metalpollution riskKrigingindicator Krigingspatial distribution
国家科技期刊平台
NSTL
万方数据
维普
