Down stream flood inundation due to assumed breaching of Mangla Dam, Pakistan | |
| Author | Khan, Noor Muhammad |
| Call Number | AIT Thesis no.WM-95-05 |
| Subject(s) | Dam failures--Pakistan Mangla Dam |
| Note | A thesis submitted as partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering |
| Publisher | Asian Institute of Technology |
| Series Statement | Thesis ; no. WM-95-05 |
| Abstract | Dam break studies of the large dams are very much important for planning disaster prevention and evacuation strategies. Mangla Dam is one of the world's largest earth and rock filled dam, built across Jhelum River, Pakistan. After exceptionally high flood of 1992, causing about one thousand casualties and an estimated loss of about US$ 2.2 billion, the need of a dambreak analysis for Mangla Dam is felt. No one explored this site before, for applying the dambreak analysis. This study is done mainly to predict the peak discharge and water level at Jhelum Bridge near Jhelum city in case of assumed failure of Mangla dam. A sensitivity analysis for different parameters of dam-breach and flood routing is also canied out. The study is confined to a reach of 65 Km between Mangla dam and Rasul Barrage. The hydrological data is mainly collected from Punjab Irrigation Department and data about Mangla dam is obtained from Water and Power Development Authority, Pakistan. The study has been accomplished using Hydrodynamic Module of MIKE 11 of Danish Hydraulic Institute. Fully dynamic Saint Venant equation is used for flood routing. As first case Jhelum River is considered as compound channel for flood routing. Secondly, a network of the channels, comprising of flood cells and connecting channels, is constructed for the flood routing. The gauging station at Mangla dam, Jhelum Railway bridge and Rasul Barrage are considered as upstream boundary, calibration point, and downstream boundary, respectively, for calibration of the model. The model calibration is done by using the flood flow data measured in the period of July 1988 and September 1992. The results of calibration is found to be very satisfactory. For dam-break computations two methods of dam-breaching are used: a). user specified breach section b ). dam-breach calculated by Engelund Hansen formulae. The down stream boundary for dam-break case is taken to be an extended rating curve at chainage 57.35 Km, a few kilometers upstream of Rasul Barrage. The results show that shape of breach and mode of triggering of breach has major effect on resulting peak discharge and time of peak. At the Jhelum bridge a maximum water depth of 18.75 m with a peak discharge of 142,000 m3/sec was observed due to trapezoidal dam break case with a network of channel. The study can be used for developing the evacuation plan for the Jhelum city located down stream of Mangla dam. This will also help in planning the flood protection schemes in the area. |
| Year | 1995 |
| Corresponding Series Added Entry | Asian Institute of Technology. Thesis ; no. WM-95-05 |
| Type | Thesis |
| School | School of Civil Engineering |
| Department | Department of Civil and Infrastucture Engineering (DCIE) |
| Academic Program/FoS | Water Engineering and Management (WM) |
| Chairperson(s) | Tawatchai Tingsanchali; |
| Examination Committee(s) | Hans Christian, Ammentorp;Kyotoh, Harumichi; |
| Scholarship Donor(s) | DAAD (Germany); |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1995 |