TITLE:
Flash Floods and Groundwater Recharge Potentials in Arid Land Alluvial Basins, Southern Red Sea Coast, Egypt
AUTHORS:
F. Abdalla, I. El Shamy, A. O. Bamousa, A. Mansour, A. Mohamed, M. Tahoon
KEYWORDS:
Flash Floods, Wadi El-Gemal, Groundwater Recharge, GIS, Red Sea Coast, Egypt
JOURNAL NAME:
International Journal of Geosciences,
Vol.5 No.9,
August
22,
2014
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.