Estimation of Flood Hazards Using Hec-Ras 1D: The Case of Al-Musandaq Escape

Floods have been considered amongst the most recurring and devastating natural hazard types as they result in extensive economic losses to humans and infrastructures worldwide. Maysan city in southern Iraq is prone to recurrent floods and was severely affected by the Flood 2019 in the recent past. Flood hazard estimation is an important strategy for flood control and flood hazard reduction. This study was focused on the Flood Hazard Estimation in the River Tigris from the downstream of Al-Kut Barrage to Al-Musandaq Escape of 169 km in length. by utilizing the HEC-RAS model. Sixty two cross-sections surveyed in 2017 have been utilized in this study. information related to the hydrological and topographical Digital Elevation Model data has been utilized as input data. The flood estimating data was found to be accurate when compared to past studies and research, as well as the data employed, indicating that the HEC-RAS software can be used to accurately estimate floods. To control the flood and to protect Maysan of the related risks, the study suggested designing a weir at the front of Maysan and having a specific level where no more than 700 m3/s drainages are allowed to pass, as the drainage of 700m3/s and more causes dangers to Maysan.