Dam failure analysis and flood disaster simulation under various scenarios

Abstract

The aim of this study is to analyze the effects of a possible dam failure under various scenarios and to generate a flood hazard map for two consecutive dams located in a study area with a dense-residential region and a heavy-traffic highway. Two consecutive dams consist of Elmalı 2, a concrete-buttress dam and Elmalı 1, an earth-fill gravity dam in the upstream and downstream, respectively. Hydrologic Engineering Center-River Analysis System (HEC-RAS) was used to develop a dam failure model. Dam failure scenarios were examined regarding three main criteria: the Breach Formation Time (BFT), the Number of Failed Buttresses (NFB) of Elmalı 2, and the Reservoir Volume Ratio (RVR) of Elmalı 1. Accordingly, flood peak depth (Hp), peak flow rate (Qp), peak velocity (vp), and time to reach the peak (tp) are discussed. The results showed that BFT and NFB of Elmalı 2 were highly effective on these values, whereas RVR of Elmalı 1 had no significant effect. Moreover, the total area affected by potential floods was calculated with a comparative areal change analysis using flood inundation and flood hazard maps obtained. Estimated damage costs indicate that in the worst-case scenario, more than 500 buildings will be affected in the region. HIGHLIGHTS The effects of a possible dam failure on two consecutive dams are analyzed.; The study focuses on the dam failure analysis of a concrete-buttress dam located on a high-density residential area and a heavy-traffic highway, which is different among dam failure studies.; Flood inundation and hazard maps for the study area are generated.; The results obtained in this study serve as a guide for those living downstream of the Elmalı dam in the future.;

Keywords

• buttress dam
• consecutive dams
• dam failure analysis
• flood hazard map
• hec-ras