Document Type : Research Paper

Authors

• Fatemeh Rahimpour
• Rahim Ali Abbaspour

Abstract

Awareness of the spatial distribution of heavy metals concentrationfor monitoring soil contaminationand maintaining the quality of the environment is essential. This research was carried out with the aim of providing the spatial distribution map of Manganese, Copper, Zinc, and Iron heavy metals contamination concentration in agricultural landsof Harris city located in the province of East Azerbaijan. To this end, 370 surface soil samples were collected at the depths of 0 to 30 cm using a randomized systematic sampling method, and the total concentration of these metals was measured in them.In order to model the spatial variations of heavy metals concentration in the soils of the region, the ordinary Kriging and Radial Basis Functions (RBF) were used in the ArcGIS environment. Among the various models of ordinary kriging and Radial Basis Functions, the lowest RMSE and MAE values and the very close proximity ofthe MBE statistic to zero, and the highest correlation coefficient (R) were considered as the criterion for the evaluation of the best method for modeling the distribution pattern and the scattering of heavy metals.Both methods had a good accuracy, but based on the evaluation criteria,the Kriging method with Exponential model was selected for Magnesium and Copper, and with spherical model for zinc, andthe RBF method with Multi-quadric function was selected for iron. The zoning map was drawn after selecting the superior model for each of the elements, and was classified by taking the standards of the Soil and Water Conservation Institute into consideration, and the elements were categorizedinto four classes ofscarce, adequacy, high, and contaminated.The analysis of the spatial distribution map of the heavy metals contamination under study showed that most of the lands were in the range of adequacy for the Manganese element; for Copper element it was found that about 92% was in the high class, and about 8% of the study area was contaminated. For the zinc and iron elements, not only no contamination was observed, but about 96% and 80% were scarce respectively. 

Keywords

• Soil contamination
• heavy metals
• Kriging and RBF
• GIS
• Harris city