摘要

The total contents of eight soil heavy metals (Cr, Zn, Cu, As, Pb, Mn, Ni, Cd) and pH of 51surface soil samples in the study area were measured to explore the source, distribution and pollution degree of the soil heavy metals in the Qinwangchuan Basin. The multivariate statistics, geostatistical methods and GIS technique were used to investigate the sources, spatial variability and distribution of soil heavy metals, while the pollution index and fuzzy comprehensive evaluation methods were applied to evaluate the soil heavy metal pollution. Results indicate that the average concentrations of Zn and Ni were greater than the local background values, while the others were lower than the background values. The variability of Cd was significant, whereas others were medium;the concentrations of Zn and Cr conformed to lognormal distribution, and the rest followed the normal distribution;Cr, Cu, As, Pb and Mn were the natural sources of soil matrix, Cd and Ni were mainly sourced from industrial and traffic pollution, while Zn was mainly sourced from agricultural production activities. The concentration profiles of Zn, As, Ni and Cd were island-like, and the Cu and Mn were banded, while the Cr and Pb are the mixed pattern of island-like and band-like. The the pollution index evaluation results show that Cr, Cu and Pb were on alert, As, Mn and Ni were lightly polluted, Cd was moderately polluted, and Zn was highly polluted. Fuzzy comprehensive evaluation showed that only one soil sample was mildly contaminated and two were in alert level, and the rest were within the safety scope. The soil environmental quality standards were the basis for soil quality evaluation. It can be observed that the soil quality of all the samples were within the national secondary standards and the environmental quality of soil heavy metal in the study area was generally good.

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