Monitoring Flood Waves Due to Overtopping: Case Study of Mosul Dam from Iraq

Abstract

When highlighting water resource exploitation and environmental management, interest in dam break hydraulics is growing due to the possibility of hydrological events brought on by climate change and the catastrophic dam breaches that often result in severe loss of life.  Several areas are exposed to flooding risk due to flood waves resulting from dam failure. The current study aims to apply a numerical model that predicts the flood wave's characteristics due to a hypothetical overtopping failure in two dimensions. A numerical model (hydrologic engineering center river analysis system 2D HEC-RAS) is implemented in this study. Mosul Dam, located on the Tigris River in Iraq, is utilized as a case study in this work. The 2D flow area was delineated on the digital elevation model to determine the inundation region and extracted n manning from a land cover layer connected with RAS MAPPER. The results explained that the maximum values of the depth and velocity in km 5 are 60 m and 10.10 m/sec, respectively. At the same moment, it is shown that maximum flood discharge happened near the dam body and that there is a roughly linear relationship between the flood flow and water surface elevation. The study concluded that the models are successful in analyzing the dam breaches by representing the variation of flood wave depth and velocity in two dimensions. Moreover, the ability of the Model to produce maps monitors the spread of hydrodynamic waves that indicate risk areas that are threatened by inundation, which aids in controlling the risks resulting from them.