Geomorphology of El-Hebal Dune Field, SE Eastern Desert, Egypt

There are four small dune fields (350-500 km2) in the SE Eastern Desert of Egypt, of which El-Hebal Dune Field is one of them. This dune field occupies a semi-closed basin at the foothills of the Red Sea Mountains. This paper will primarily analyze the geomorphological aspects of El-Hebal Dune Field to reveal its unique characteristics, which distinguish it from other dune fields in this region and in other parts of Egypt. The analysis of the geomorphological characteristics of this dune field relies on the interpretation of Landsat and Google Earth images supported by field measurements and sampling of dune sands. The analysis of the available data revealed that this dune field is composed of 14 compound bundles trending NNE-SSW. All of them are composed of dunes of various forms, mainly linear, barchans, and lee dunes. Each bundle is composed of five to eight thin linear dunes that dismantle into barchans at their lower sections. Lee dunes represent a prominent aeolian form developed in this dune field due to the prevalence of low sandstone ridges lying perpendicular to wind direction. The growth and unification of lee dunes led over time to the development of the linear dunes. Barchans developed at the downwind sections of the linear dunes. They are relatively smaller than others in other sand seas and in most dune fields in Egypt, with short horns and slip faces or without. Sand is derived from two main sources: theuvial sediments deposited by wadis on the bahada and along the beaches of the Red Sea, and a secondary external source, from which sand is brought by the coastal current running along the Red Sea western coast in the southern direction. According to available evidence, a Holocene age is suggested for the development of this dune field.