Tingsanchali, Khan: Prediction of Flooding due to Assumed Breaching of Mangla Dam Prediction of Flooding due to Assumed Breaching of Mangla Dam Case Studies: Dam Break Tawatchai Tingsanchali, Noor Muhammad Khan Parallel Session (parallel43), 02.09.1998, 10:15 - 12:45 Dam Break Modelling Abstract The Mangla Dam is one of the world's largest earth and rock filled dam, built across the Jhelum River, Pakistan. Downstream of the Mangla dam there are major towns such as Jhelum, Rasul, Khushab, etc. In 1992 a very large flood occurred due to excessive inflow into the reservoir and very large release from the Mangla dam caused a large number of casualties and an estimated loss of US$2.2 billion. Due to this serious incident, flood mitigation and evacuation plan is deemed necessary. This study is done to predict the peak discharge and water level due to an assumed failure of the Mangla dam. The dam breach computation is done by using the MIKE 11 dam break module while the downstream flood routing of the dam breach outflow is done by using the MIKE 11 hydrodynamic module. The considered reach of the Jhelum river is from the Mangla Dam to the Rasul barrage, a distance of 65km. The hydrodynamic model is calibrated using the flood data in July 1988 and September 1992. The calibration is found to be satisfactory. The model is applied to predict the flooding downstream of the dam due to an assumed dam breaching. The results are analyzed and discussed. 1. Introduction Originating from the valley of Kashmir, the Neelam River and the Kunhar River join along with other small tributaries to form the Jhelum river. Just at the border of Pakistan and Azad Jammu & Kashmir, one of the world's largest dams, the Mangla Dam (115m high) is located, encompassing an artificial reservoir (capacity 6,780 million cubic meter) across the Jhelum River. Downstream of the Mangla dam are located some of the major towns of Pakistan named, Jhelum, Rasul, Khushab, Sargodha Jhang, etc. The failure of the Dam due to any reason is a hanging sword for the people living on both sides of the river, especially to those in the Jhelum district just a few kilometers downstream of the dam. "Planning for efficient action rather than reacting to the crises when it occurs" depicts the need of dam-break analysis of all dams in the world well before their construction. Development of new concepts in the area of dam-break analysis and the progress of computation techniques and computing technologies since the design and construction of the Mangla Dam in 1965 also make it important that the dam-break study should be undertaken with state of the art methods and latest data. file:///D|/user/Lehfeldt/ICHE/1998-Cottbus/Document/Cas.Dam.278.paper.html (1 von 10) [19.11.02 14:04:27]