Urban Landscape and Flash-Flood Hazard on Alluvial Fans in a Hyper-Arid Zone—The Gulf of Eilat/Aqaba

Overlooking the Red Sea, the desert cities of Eilat (Israel) and Aqaba (Jordan) are located in a strategic, economic, and trade junction. The cities were built on a series of alluvial fansAlluvial fan and a playa in-between; the only gentle slopes between the steep mountains and the sea that can accommodate large urban settings. Nevertheless, flash floodsFlash floods, which used to split, attenuate, and deposit sediments on the alluvial fansAlluvial fan, are now disgorging from the mountain front into the urban areas. The attempts to mitigate the flood hazard by diversion canal/detention ponds yielded a fallacious sense of security; sedimentation reduces canal/ponds capacity and the floods breach into urbanized areas without warnings, causing destructive floods, often larger than natural flash floodsFlash floods. Moreover, the diversion canals only transfer the risk downwards to the Eilat playa, an area of the utmost economic importance. Today, the cities are spread over the alluvial fansAlluvial fan and therefore, flood prevention strategies become increasingly complex and unsustainable. However, the last 70 years demonstrate that floods can cross the cities with little appreciable damage, only by minor shifts in the priorities of urban design. The incorporation of urban segments like recreation areas, football fields, main roads, parking lots, etc., into flood prevention schemes may lead to more sustainableSustainable flood management solutions while reducing flood risk.