Application of Geostatistical Methods to Heavy Metals Status in Carsamba Plain Soils

Abstract

The understanding of the spatial variability of soil heavy metals is an important precondition for potential contamination risk and evaluating eco-environment quality in a primary arable soil. To date, little research on soil pollution in carsamba delta plain has been conducted. To identify the concentrations and sources of heavy metals. 174 soil samples (0-20 cm) were collected from the study area. Subsequently, the concentrations of Cd, Co, Cu, Ni, Pb and Zn in the samples were analyzed. In order to evaluate natural or anthropogenic sources of heavy metal content and their spatial distribution in agricultural fields of carsamba delta plain and near district soil, statistics, geostatistics and geographic information system (GIS) were used. GIS technology was employed to produce spatial distribution maps of the 6 elements. The results showed that the concentration of Ni exceeded its threshold level. The local pollution from Ni was attributed to the natural and anthropogenic influences. The concentrations of the other heavy metals are relatively lower than the critical values. The mean-values of the heavy metal contents arranged in the following decreasing order: Ni > Zn > Cu > Co > Pb > Cd in the study area. In some regions of the study area, the Cd, Cu and Zn contents were also slightly raised, possibly due to excessive P fertilization and field traffic.