Dam break risk analysis and flood inundation mapping: a case study of Wadi Al-Arab Dam

Investigating the risk analysis of dam-break scenarios is crucial for accurately predicting flood levels and the arrival time of downstream flood waves. This is essential for mapping floods and preparing emergency plans. This study focuses on the risk analysis of dam breaks in the Wadi Al-Arab Dam in Jordan. This study specifically examines dam breach modeling using the Hydrologic Engineering Center-River Analysis System software to assess downstream areas, utilizing a Digital Elevation Model. Design storms were employed to calculate the Probable Maximum Flood flow hydrographs using the Watershed Modeling System. River Analysis System-Mapper was utilized to create two-dimensional flow areas. The breach parameters were estimated after generating equations utilizing multivariable linear regression of previous dam failure events, considering their characteristics and failure modes. Two-dimensional hydraulic simulations were conducted for overtopping and piping scenarios. The results were visualized using RAS Mapper, which provided maps of the inundated areas. The estimated maximum water depth for overtopping was 37.6 m, whereas that for piping failure was 26 m. The peak breach flow was estimated to be 10,800 m3/s for overtopping and 3234 m3/s for piping failure. The potential impact of the flood was evaluated in Shooneh Shamaliyah, a small city with a population of 21,306. This study emphasizes the significance of effective emergency planning and effective response in reducing possible damage. Furthermore, it provides valuable information for estimating the flood risk related with the Wadi Al-Arab Dam failure.