Geochemistry of soil and groundwater in arid regions: Qatar as a case study

This study aims to merge the findings of soil and groundwater geochemistry analyses for the same locations, and to investigate the natural and anthropogenic factors affecting the interaction and, inter-linkages among different parameters (with special care to contaminants that may affect environment), and human health. A broad spectrum of physicochemical parameters, including anions, cations, heavy metals, and rare earth elements have been analyzed for the first time on this scale of sampling campaigns using state-of-the-art laboratories inside Qatar. The results of 250 groundwater samples and 310 topsoil samples showed a very strong correlation for major cations (Ca, Mg, Na and K) and common heavy metals (Pb, Fe, Mn, Zn and Co) in both water and soil. One big challenge in studying soil geochemistry in Qatar is the importation of fertile soils from Asia to the agricultural areas. The harsh arid environment and naturally occurring sand/dust storms and soil erosion increase the complexity. More studies on soil mineralogy and geochemistry are needed to identify the exact sources of elevated parameters in groundwater and soil. The findings of the study are important to the region and for countries worldwide that have similar conditions of aridity, water scarcity, and human development. Additionally, a good understanding of groundwater geochemistry should be coupled with soil geochemistry. Such coupling gives powerful tools to plan both land use and water management strategies.