Preliminary Magnetic Susceptibility Results from the Northwestern Part of Madinah, Saudi Arabia: Environmental Degradation of Wadi Aqiq

Abstract

Recent advances in environmental magnetism have led to new applications in understanding soil pollutions from anthropogenic sources. The utility of environmental magnetic techniques varies widely depending on biological, chemical and physical processes that create and transform soils and sediments. Researchers in some European and Asian countries have successfully studied heavy metals in top soils using magnetic susceptibility technique. Accelerated urbanization in the past two decades has significantly altered the environmental landscape of Madinah. A famous wadi Aqiq in the heart of Madinah, an important conduit for groundwater recharge, is one of the most affected. This study thus focuses on magnetic susceptibility application as environmental magnetic technique to map heavy metal concentrations in top soils along wadi Aqiq, northwestern part of Madinah. Higher values of magnetic susceptibility from soil cover than those from parent igneous rocks indicate anthropogenic origin metallic contamination in the study area. The trucks/tankers parking area reveal highest values of magnetic susceptibility. The areas close to heavy vehicular traffic along two major roads also indicate higher magnetic susceptibilities because of enhanced metallic contaminations. The areas covered by residential and commercial buildings reveal medium level of magnetic susceptibilities. The left over asphalted materials at various places in the area is another source of high magnetic susceptibilities. Widely distributed metallic objects in the area, such as hangers, cans, and construction materials also contribute to enhanced soil contamination as evident from high magnetic susceptibilities.