Dam Breach Parameters and its Effects on Propagation of Flood Wave in the Downstream

Abstract

Our society gets huge benefits from the water storage dams, but the consequences are devastating if a dam fails. It causes extensive damage to the life and properties mostly due to short warning time. Important factors governing failure studies are the breach parameters that help to quantify the risk associated with dam break floods. Many empirical equations have been developed for predicting the breaching parameters associated with peak outflow and these equations are generally developed by regression analysis from the record of dam failure data. In the present work, a hypothetical failure of dam is modelled using MIKE 11. The required inputs in terms of PMF, river cross sections, area-elevation-capacity curves, Stage-Discharge data and dam specifications are provided for modelling. Towards this, data from Sarabgarh dam project in Orissa is used to model the breach parameters and propagation of flood waves in the downstream reaches using Mike 11 and other software. The flood hydrograph at different stations are analyzed to estimate the risk of overtopping of river bank and flooding. Besides a sensitivity analysis for various parameters that affects the maximum discharge and maximum water level has been carried out successfully.