Environmental Engineering Risks Assessment of Sand Dunes, North Jeddah, Saudi Arabia

摘要

The study area is located in the west central part of the Arabian shield along the Red Sea coastal plain. It comprises of old igneous and metamorphic rocks of the Arabian Shield overlain directly by the tertiary sedimentary succession and finally the tertiary basic volcanic flows (Harrat). The studied sand sheets and dunes cover the different rock units of the study area mainly within the flat areas and wadies. Due to arid rainless continental climatic conditions and geology about 37% of Saudi Arabia is covered by desert sands. These sands are mostly dynamic and causing environmental problems. The study area is considered as one of the most important, promising and strategic coastal areas between Jeddah and Rabigh. This coastal area is characterized by its plains and flattened ground so that the dynamic and migrated eolian sands (sand dunes and sand sheets) are on the most famous landforms in this area. The most common dunes are barchans, longitudinal rarely star-like dunes. These eolian sands are dynamic and migrate from one place to another so threatening communities and farms as well as highways and railways.