Mapping Soil Contamination in Arid Regions: A GIS and Multivariate Analysis Approach

Heavy metal soil contamination is a global environmental issue that poses serious threats to human health, agricultural advancement, and ecosystem systems. Thirty-five soil samples from various parts of Jazan, Southwest Saudi Arabia, were collected. To create spatial pattern maps for nine potentially toxic elements (PTEs) (As, Co, Cr, Cu, Fe, Ni, Pb, V, and Zn), Ordinary Kriging (OK) was utilized. The variability of the soil metal concentration was estimated using multivariate analysis, including principal component analysis (PCA) and cluster analysis. In addition, the levels of soil contamination in the research area were assessed using contaminations indices, namely, Enrichment Factor (EF), Contamination Factor (CF), and geoaccumulation index (Igeo), and modified contamination degree (mCd). Normalized Difference Vegetation Index (NDVI) and land use/land cover (LULC) were assessed to evaluate vegetation density and identify different forms of land cover and land use. The results showed that the Gaussian model fitted As well, whereas the spherical model fitted Co, Cr, Cu, Ni, and Zn. An exponential model was fitted to Fe and V. Pb also suited the Stable model. In each of the selected metals, the root mean square standardized error (RMSSE) values were close to one, and the mean standardized error (MSE) values were almost zero for each fitted model. Moreover, the findings showed that there was a tendency for the concentration of heavy metals in the research area to rise from west to east. The cluster analysis divided the data in this investigation into two clusters. Significant alterations in Co, Cr, Cu, Fe, Ni, V, and Zn were revealed by the acquired data. However, the total As and Pb concentrations in the two clusters did not differ significantly. The mCd value of the research region often fell into one of three classes, with areas of 148.20 km2 (nil to very low degree of contamination), 26.16 km2 (low degree of contamination), and 0.495 km2 (moderate degree of contamination). The findings indicated that the minerals connected to the Arabian Shield&rsquo:s basement rocks are the main source of these PTEs. It is crucial to monitor PTEs contamination because the research region is highly cultivated, as shown by the NDVI and LULC status. Given the potential for future pollution due to human activity, PTEsPTEs decision-makers may use the findings of the spatial distribution maps of pollutants and their concentrations as a basis for future monitoring of PTEs concentrations in the study area.