Dam Break Analysis Using Hecras for Nagarjunasagar Dam

Abstract

In dam failure analysis provides the generating the flood inundation maps of Srisailam dam to Nagarjuna Sagar dam and its downstream. Flood inundation maps utilized to protect against the loss of life and property damage from maximum flood. The hydrologic engineering center’s river analysis system (HEC-RAS) can be used in combined with HEC-GEORAS to develop a dam failure modes. For extract geometric information from digital terrain modes to used HEC-GEORAS and then imported in to HEC-RAS used for the unsteady flow simulation of dam break is performed and results are mapped in the ARC-GIS. In this thesis inundation mapping of water surface profiles provides a preliminary assessment of the flood hazard. The process of gathering data and preparing data and analysis of unsteady flow model in HEC-RAS, entry of dam breach parameters, performing the failure analysis and flood mapping in ARC-GIS is discussed. This Thesis mainly provides an overview of the methods used to predict the breach outflow hydrographs with a detailed case study of hypothetical breach failure of dam“Nagarjunasagar dam” using HECRAS software. This Dam breaks are analyzed for failure with comparison of the hydrographs at different downstream locations by changing its breach parameter using HECRAS. The parameters describing a breach are typically taken to be the breach depth, width, side slope and breach formation time. Wahl (1998) and Wahl (2004) and Froehlich (2008) have found them to be very significant, especially the time parameter.