Geomorphological Features, Sediment Distribution and... 57 Geomorphological Features, Sediment Distribution and Transport Along Ash Shuqayq-Al Huraydah Coastal

Abstract. The coastal area under investigation stretching from Al Hu-raydah in the northwest to Itwad in the southwest. It lies about 6oo km south of Jeddah on the southern Red Sea coast. It extends inland more than 40 km and is bordered by the shield escarpment. The geomorpho-logic features, shoreline configuration, sediment characteristics and dynamics has been established for understanding the processes that in-fluence the coastal environments. The shoreline of the studied area is not linear and smooth, instead it is complexed by arcuate beaches, sharms, inlets, lagoons, barriers and rocky hills. The width of the coastal plain varies widely, it is wide and featureless towards south of Ash Shuqayq while being narrow and bounded by resistant sea cliffs towards the north. Ash Shuqayq coastal landforms include; marsh system, inlet and swamps, wave swash, dunes, shoreline processes, beach bars, spit sys-tem, wadi systems and sabkha systems. Conditions on such beaches change rapidly. In conclusion, the coastal area of Ash Shuqayq can be divided into two principal geomorphic zones: (i) The northern zone stretching from Al Huraydah is characterized by rocky highlands, very rugged with high sea cliffs and small pocket beaches that disrupt wave in-duced longshore sand transport. (ii) The middle and southern zone stretching from Ash Shuqayq to Itwad southward, is generally broad low relief depositional coastal plain. The shore zone profile is feature-less-wide beaches backed by extensive and longitudinal foredunes fixed by coastal vegetation. Sediment cover is thick with numerous wadis drained in the area and contributed the vast majority of the total input of sediments to the coastal zone