Abstract
Flash flooding is one of the periodic geohazards in the southern Red Sea Coast. However, their freshwaters are the main source of recharging alluvial and fractured aquifers. This paper presents hydrological and geomorphologic classification of Wadi El-Gemal, Wadi Umm El-Abas, Wadi Abu Ghuson and Wadi Lahmi, along the southeastern Red Sea Coast in Egypt. The main goal is to find a relationship of flash floods and groundwater recharge potentials. Satellite imageries and topographic data were analysed via remote sensing and GIS techniques. The main four valleys’ orders range from six to seven. Wadi El-Gemal was the main focus of this study; it is characterized by high stream frequency, low stream density and coarse texture, reflecting influence of highly fractured Precambrian rocks. Most of the wadis have umbrella-shaped catchment areas, due to the influence of NW-SE Najd Fault System and late E-W strike-slip faults. The main wadis were divided into 45 sub-basins. 14 of the studied sub-basins flow into Wadi El-Gemal, 7 flow into Wadi Umm El-Abas, 10 are in Abu Ghuson, and rest of the basins flow into WadiLahmi. A conceptual model was used in this study, showing that most of the sub-basins have high flash flooding and low groundwater recharge potentials. However, only two sub-basins have low potential of flooding and high potential of groundwater recharge, whereas few sub-basins have moderate potential of groundwater recharge as well as flooding. For flash floods beneficiation and mitigation, construction of multifunctional embankment dams is imminent.
Highlights
Hydraulic geometry and geomorphologic analysis provide better understanding of alluvial basins nature and occasional geohazards that can obstruct projects of development [1]
This study focused mainly on Wadi El Gemal basin; it analyzed in details
Adequate numbers and different sizes of bridges should be built for passages
Summary
Hydraulic geometry and geomorphologic analysis provide better understanding of alluvial basins nature and occasional geohazards that can obstruct projects of development [1]. Countries located in semi-arid to arid regions, such as Egypt, have alluvial (wadi) systems, formed during fluvial time of the Tertiary and Quaternary periods. These wadis suffer from flash floods, consequent to heavy precipitations. A flood that involves a widespread, runoff flow event in an arid basin were intense showers exceed the infiltration capacity of the soil surface is quite different from a major overbank event in the lower reaches of a large river system, driven by excessive persistent basin-wide precipitation [2]. Flash floods occur occasionally in wadis that pour into the Red Sea Coast ata specific time of the year. They should be taken seriously as natural hazardphenomena
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
