Hydrologic Analysis for a Hyper-Arid Region in the Middle East

Flash flooding in a mountainous region of the Kingdom of Jordan, near the Red Sea, produces quick-response, high-volume and peak flow floods that have caused extensive property damage and loss of life. In February 2006, the combination of high relief and extreme climate aridity resulted in flash flood conditions that caused five fatalities and extensive damage to infrastructure. The flooding disrupted power and water supplies and damaged the wastewater treatment plant, causing significant environmental degradation and substantial hardship for the people in the town of Aqaba, Jordan's only shipping port. The port is crucial to the Jordanian economy and protection of the city from flood damage is critical to maintaining development and public safety. Recognizing the need to protect existing and future infrastructure, a flood hazard mitigation plan was developed for the Aqaba Special Economic Zone Authority of Aqaba, Jordan, through a grant from the United States Agency for International Development (USAID). This comprehensive study included a hydrologic analysis to predict peak flows and hydrographs. The hydrology methodology utilized available geographic information system (GIS) tools to automate the generation of data needed for development of a hydrologic model. Peak flow and hydrograph predictions were used as input for hydraulic, sediment transport, and flood hazard mitigation alternative analyses. This paper describes the data acquisition and methodology used to develop hydrologic characteristics and presents the hydrologic model used to simulate runoff hydrographs resulting from the design storm rainfall.