Engineering Geological Map of Jazan City, Kingdom of Saudi Arabia
Hassan M. Al Harbi, Ahmed M. Youssef, Mohammed Baamer, Khalid Z. Al-Ahmadi, Turki Sehly,
Abdelfatah F. Khayat, Abdullah A. Al-Otaibi, and Mohammed I. Al-Zahrani
Located in the southwestern corner of the Kingdom of Saudi Arabia, Jazan City is one of the country’s largest cities with about 100,700 inhabitants according to the 2004 census. In recent years, the Saudi government has put a lot of effort into developing this part of the country. Nowadays there is intensive urban and industrial development, with new infrastructure and planned areas for industrial zones. However, various types of geological and geotechnical problems have cropped up since its rapid expansion. For this reason, the Saudi Geological Survey initiated a detailed engineering geological mapping of Jazan City in 2005. Discounting small hills within and outside the city, Jazan is located on an essentially flat area along the Red Sea coast. It is bordered to the east and south by mountainous terrains. A tributary of Wadi Jazan is located along the northern section of the city. Detailed geologic mapping revealed that the area is underlain by different lithological units including salt domes, sabkhas, sand dunes, and loess soils, the latter representing the overlying Quaternary sequence. Together with flash floods, they constitute the geologic hazards which may impact the urban development and expansion unless serious remedial action is taken By using the system recommended by the International Association of Engineering Geology and based on the USC system, in-situ surface and subsurface investigation, laboratory analyses, desk studies, and analysis of supporting data collected from different agencies, and satellite images were carried out to characterize the rock and soil samples. The results were used to generate various comprehensive engineering geologic maps for different geotechnical parameters including water table depths and Standard Penetration Test N values among others. Various cross-sections showing the different layers recognized from their geotechnical properties were also generated.
Al-Harbi, H.M., Youssef, A.M., Baamer, M., Al-Ahmadi, K.Z., Sehly, T., Khayat, A.F., Al-Otaibi, A.A., and Al-Zahrani, M.I., 2011, Engineering geological map of Jazan City, Kingdom of Saudi Arabia: Saudi Geological Survey Technical Report SGS-TR-2011-2, 43 p., 40 figs., 13 tables, 3 pls