Evaluation of Earthen Dam-Breach Parameters and Resulting Flood Routing Case Study: Aidoghmosh Dam

Abstract — Dams are constructed for a specific purpose such as agricultural water supply, flood control, irrigation, navigation, sedimentation control, and hydropower. Using the most recent publication of the World Register of Dams, irrigation is by far the most common purpose of dams. Simulation of dam breach events and the resulting floods are crucial to characterize and reduce threats due to potential dam failures. The studies of dam breach are necessary and important in academic studies, the governmentʹs planning and investment in downstream of the dams. In this research, considering the importance of the dam breach studies and resulting flood routing, based on the previous studies, new equations were presented for estimating dam breach parameters (breach width, side slope, time of failure and peak outflow) by collected data from 142 broken dams. Dimensional analysis and multiple regression were used to predict maximum outflow from earth dam breach. The uncertainty of equations was evaluated. In this way, geotechnical equation of the BREACH model was adapted. This modification was evaluated by the data of pervious broken dams and revealed better results. Finally as a case study, Aidoghmosh dam breach was analyzed using the presented equations of breach and a flood routing model. According to the results obtained from the examined dam breach, equipment of wastewater refinement, four connective bridges of the railway and some parts of the town near the railroad are exposed to the danger of the flood resulting from the dam breach.