Spatial distribution of some heavy metals in two agriculture and rangeland uses (A case study: Shahzand industrial city, Arak)
Subject Areas : Natural resources and environmental management
Leila Zarei
1
(MSc. of Soil Science, Faculty of Agriculture, Malayer University, Malayer, Iran)
Soheila sadat Hashemi
2
(Assistant Professor, Department of Soil Science, Faculty of Agriculture, Malayer University, Malayer Iran)
Mahdi Najafi Ghiri
3
(Associate Professor, Department of Soil Science, College of Agriculture and Natural Resources of Darab, Shiraz University, Iran)
Keywords: Geostatistics, Kriging, Lead, pollutant, Cadmium,
Abstract :
Soil is a natural environment for plant growth and due to its importance, the study of heavy metal distribution for soil contamination monitoring and environmental quality maintaining is necessary. This investigation was performed to study the spatial variability of some heavy metals in some surface soils of the Shazand City. A total of 76 soil surface samples were randomly collected from a depth of 0-30 cm in the study area. After preparation of the samples, some physico-chemical characteristics and the total amount of, lead (Pb), cadmium (Cd), nikel (Ni), zinc (Zn) and copper (Cu) were measured. Mean concentrations of Pb, Cd, Ni, Zn and Cu were 31.20, 54.12, 23.11, 2.05 and 59.36 mgkg-1, respectively. Significant correlations were found between Ni with Cu (r= 0.41, p<0.01) and Zn (r= 0.5, p<0.01). Also, a significant correlation was obsrved between Cu and Zn (r= 0.4, p<0.01). The spatial variability of these variables was examined by variogram models and ordinary kriging. The results of geostatistical analysis showed that the spherical model was the best model for describing the spatial variability of all studied elements. Strong spatial dependence (the ratio of nugget to sill less than 0.25) was obtained for the lead element. According to the standard limits, Pb and Cd showed the highest pollution in rangeland and agricultural land use in the study area, respectively. It’s recommended to increasing soil quality and reduces it’s degradation from pollutants applied proper environmental proceeding.
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