Hydraulic characteristics and Flood Zoning Analysis of Givi Dam Break flow

The collapse of a reservoir dam could have extensive and destructive effects on the downstream facilities and in addition to financial losses, they could lead to casualties if they pass through residential areas. Accordingly, knowing the characteristics of the floods created in different downstream areas of the dam is useful in determining the critical downstream points that are exposed to the potential dangers of the dam break caused by flood. In this paper, the floods caused by overflow discharge and failure of Givi earthen dam in Ardabil province are simulated numerically. Accordingly, Mike-Flood module is used, which is a combination of one-dimensional Mike-11 and two-dimensional Mike-21 modules. In this study, the Probable Maximum Flood (PMF) scenario to create the overtopping mechanism along with sunny day scenarios for piping mechanism are addressed in two cases of reservoir filling and the sabotage scenario as a sudden dam break. The results showed that the most critical scenarios were related to the sabotage, the Probable Maximum Flood (PMF) and the sunny day scenarios, respectively. Under these three scenarios 19%, 17% and 13.5% of the southern part of Givi city (located near Givi river), as well as all the villages located between Givi dam and Firoozabad village (on the left bank of Givi Chai river), and Firoozabad village will be completely submerged.