Ghodadoha is a rock-filled earthen dam located in one of the tributaries of the Rushikuliya river of Orissa.
The study helps assess the flood magnitude and its behavior so as to make a preparatory plan to safeguard the lives and properties on the flood plains of the river downstream of the dam structure. To estimate the amount of flood discharge reaching at different sections along downstream channel, a large number of mathematical models are reported in literature.
One of the models, DAMBRK developed at the National Weather Service, USA is the most widely accepted model owing to its various capabilities and advantages. The model could be employed in different levels of data availability and is reported to be efficient in computing the flood hydrograph after the breach.
The data used for the analysis includes elevation details of the spillway and dam, spillway-rating table, elevation capacity table for the reservoir, design hydrograph for dam and cross sectional details of various downstream reaches. From the simulation, it is observed that the outflow peak over the spillway is 1776.4 cumec. The dam break flood reaches a peak discharge of 4402.9 cumec at the dam site in half an hour and the propagated flood downstream of the dam travels 28.43 km in four hours with a peak discharge of 3359.1 cumec.
A sensitivity analysis was also carried out to study the effect of influencing parameters such as breach length, time of breach and bed roughness, on the flood wave propagation. The analysis indicated that effect of the parameters has little influence on the dam break flood characteristics.
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