Flash Flood Risk Estimation of Wadi Qena Watershed, Egypt Using GIS Based Morphometric Analysis

Abstract

Flash flooding is one of the periodic geohazards in the eastern desert of Egypt where many parts of Upper Egypt, Sinai, and Red Sea areas were hit by severe flash floods, for example in 1976, 1982, 1996 and January 2010. The hazard degree for each sub-basin was determined using the approach developed by El-Shamy for assessing susceptibility of sub-basins to flash flooding risk. To identify at-risk sub-basins, two different methods were applied. The first method is based on the relationship between the drainage density and bifurcation ratio, and the second one uses the relationship between drainage frequency and bifurcation ratio. The three morphometric parameters (the bifurcation ratio, drainage density, and stream frequency) were extracted and calculated for each sub-basin of the watershed. Based on the final hazard degree resulting from the two methods, a detailed hazard degree map was extracted for all sub-basins. The results illustrate that there are no sub-basins with low risk of flooding. The sub-basins with the highest hazard degree are concentrated in the middle of the watershed although they have smaller areas compared with the surrounding sub-basins. The sub-basins located at the boundary of the watershed have an intermediate risk of flooding and moderate potential for groundwater recharge. This constructed map can be used as a basic data for assessment of flood mitigation and planning.

Flood Hazard Mapping and Assessment of Precipitation Monitoring System Using GIS-Based Morphometric Analysis and TRMM Data: A Case Study of the Wadi Qena Watershed, Egypt

“…Elewa et al [22] have also introduced a detailed hydromorphometric analysis for the El-Arish watershed in the north and central Sinai to highlight the priority areas for runoff water harvesting (RWH) which means concentration, collection, storage and use of rainwater by runoff for various purposes such as domestic, animal and agricultural use. Moawad et al [23] and Elsadek et al [24][25][26] argue that given its history of flash floods, Wadi Qena should be considered a highrisk area in the Nile Valley in terms of flooding and economic losses and assess the susceptibility of Wadi Qina watershed sub-catchments based on morphological parameters. The potential damage due to flash floods in Wadi Qena involves cutting off main roads, breaking water pipelines, and lossing lives.…”

Flash-flood hydrology and aquifer-recharge in Wadi Umm Sidr, Eastern Desert, Egypt

“…The wadis of the Eastern Desert are ungauged and so little is known of the flood hydrology of the region, with meteorological data being available only from coastal stations and from Qena on the Nile (Moneim, 2005;Elsadek, Ibrahim, Mahmod, 2018). The region is hyperarid with Hurghada receiving an average annual rainfall of 3 mm, Quseir to the south, 4 mm, and Qena, 7 mm (Moeyersons, Vermeersch, Beeckman, Van Peer, 1999).…”

“…Although there are numerous passing records of individual catchments being subject to flash flooding (e.g. Tregenza, 1955;Labib, 1981;Hobbs, 1990;Elsadek et al, 2018), these reports lack detail of flood wave characteristics and progression. Recent attempts to model wadi floods suggest time to peak can be as short as 8 hours in upstream locations to 17 hours nearer the coast (Sumi et al, 2013).…”

Flash Flood Susceptibility Mapping in Sinai, Egypt Using Hydromorphic Data, Principal Component Analysis and Logistic Regression

“…Abdelkareem [32] derived a flash flood hazard map for the wadi Asyuti basin in the eastern desert of Egypt by ranking and combining morphometric parameters that favor higher flood peaks and runoff. Elsadek et al [33] presented a morphometric analysis to estimate flood hazard in the wadi Qena basin. Abuzied and Mansour [34] combined normalized values of morphometric parameters to obtain hazard indices for sub-basins of wadi Dahab, Sinai.…”

“…This study also aims to demonstrate how hydro-morphometric parameters can be used for flood risk assessment in Egypt through a combination of principle component analysis and logistic regression that is robust, reliable and validated. To date, most flood susceptibility studies conducted in Egypt have used a ranking method proposed by Davis [36] to derive flash flood hazard from hydro-morphometric data, by standardizing morphometric parameters, usually in the range of 1 to 5, and then combining and classifying them into groups ranging from lowest to highest risk level [25][26][27][28][29][30][31][32][33][34][35]. However, the number of parameters can vary, all parameters are treated with the same weight as if they have an equal impact on flooding, and the classification into hazard classes is done without rules or standards.…”