GRADUAL DAM BREACH FLOW ROUTING

Abstract

ABSTRACT A large number of impounding reservoirs are constructed to meet the demand for domestic water supply, municipal and industrial water needs, irrigation, power generation etc. It is envisaged that the construction of large impounding reservoirs also involves the preparation of emergency action plan due to the collapse (masonry)/breaching (earth) of the dam, in the form of providing safety measures and relief to the affected. Large volumes of water will be released into the downstream river gorge due to failure of the dam and the extent of relief measures depend on the propagational characteristics of the flood wave. Such problems have been studied by mathematical models involving numerical solutions. These models, however, require extensive data relating to the river gorge cross-section (including roughness parameter) and the reservoir bathymetry. This analysis is further sensitive to the unknown and uncertain characteristics of the breach geometry and the time of breach development. A brief and critical review of the art of dam breach flow routing analysis presented followed by illustration of a simple numerical model for the routing of the dam breach flows to suit to the readily available data of dam and river cross-sections.