Proc. of the Geoinformatic Forum Salzburg, Salzburg, Austria, Jul 8, 2011
The presented work is aimed at using GIS techniques to produce a potential flood hazard map based... more The presented work is aimed at using GIS techniques to produce a potential flood hazard map based on geomorphic parameters and to estimate the risk degree of individual subbasin by combining normalized values of the parameters. The study area-Dahab basin-is one of the most important basins in South Sinai, which drains into the Gulf of Aqaba, Egypt. It covers an area of about 2080 km 2. Although it is located in an arid region, the basin could receive a huge amount of rainwater during one of the rare storm events. The maximum recorded value reached up to 150 million m 3 /storm. Approximately 50% of the expected rainfall could turn into flash floods to the outlet of the basin, causing catastrophic effects on existing infrastructure and surrounding environments. Based on the Aster Digital Elevation Model, the drainage pattern of the Wadi's sub-basins were delineated and compared, with topographic map sheets of 1:50,000 scale as a reference. The sub-basins were extracted and morphometrically analysed to assess flash flood susceptibility. The morphometric parameters were measured by stream number and stream length. The parameters were computed using ESRI's ArcGIS 9.3, enriched by some VB code to compute stream numbers according to Strahler Theory. The case study results show that more than 35% of the sub-basins have high susceptibility of flooding and about 60% have medium susceptibility. Basins of high and moderate flood risk require detailed studies to implement actions to protect these areas against flood hazard.
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Papers by Adel Abdou