Abstract:
Technological advances that improve social welfare also expose large numbers of people to disastrous technological failures. Losses due to such failures may lead from a disaster to a catastrophe. Over the years a large number of dams and reservoirs are constructed under various water resources management projects. Dam failures in different countries have Ied to some of the largest man-made catastrophes in the history. Dam-break induced accidents may occur more frequently and uncertain due to aging infrastructure and climate change. In fact, if a disaster cannot be avoided, individual and social structure preparedness is of great help in risk reduction. The computer simulation of dam break induced floods enables formulation of proper emergency action plan to minimize its adverse effect. In the present study, dam break analysis for a dam in central India is carried out for various scenarios and corresponding flood inundation maps are prepared from simulated results in GIS. Considering the complex topography and availability of the limited cross-sections, a coupled model combining one-dimensional for channel flow and two-dimensional for the flood plane is prepared to simulate dam-break floods.The floods of 25, 100, 1000 year return periods are estimated using the L-moments approach. Probable Maximum Flood (PMF) for dam site is also estimated.Downstream river cross-sections were surveyed using DGPS and echo sounder to setup the 1-D hydraulic model in Mikell. Two dimensional model setup is prepared in Mike 21 for rectangular grid from the DEM. Both models are coupled in Mike Flood. This coupled model is employed to simulate the release of dam break flood and its advance towards downstream. The flood inundated areas due to dam break floods for 25 year, as PMF are estimated as 334 km2, 407 km2, and 715km2and 554 km2respectively. Sensitivity analysis for various dam breach parameters is also conducted.
