Flood Risk Analysis using Demographic Data in Case of a Dam Break using HEC-RAS: A Case Study of Khanpur dam, Pakistan

Abstract

Hydrological events are becoming more extreme every day because of climate change. This has triggered a large number of disasters in the past two decades, and the rate of recurrence and intensity of these disasters are increasing, according to every study. Floods are becoming more frequent in Pakistan, causing millions of dollars to damage the national economy. Khanpur Dam sits at a critical geological location, and the concerned authorities have not yet performed a dam break analysis. HEC RAS is one of the most used software tools for studying floods, as it gives output in 2 dimensions. It performs hydrological analysis in both the x and y axes, which results in a significantly better estimate as in reality water is moving across both axes. Census data is used for vulnerability analysis, while HEC RAS output evaluates the hazard values. Risk analysis maps have been prepared using GIS software with Inverse-weight distribution as the hazard is more near waterways than the areas at a greater distance. Vulnerability and hazard values of different towns do not reciprocate as the most of the development is on higher ground which will be relatively safe in a dam-break scenario.