A Study on Dam Break Simulation considering Continuous Rainfall Events

In recent years, flood damage resulting from continuous rainfall events has been on the rise. However, existing Emergency Action Plans (EAPs) addressing reservoir or dam failure only consider Probable Maximum Precipitation (PMP), which represents a single rainfall event. This study aims to address this limitation by simulating a dam break scenario caused by continuous rainfall events. The Chungju dam watershed was selected as the study area and a mega rainfall event scenario, involving continuous 500-year frequency rainfall intensity events, was defined. Next, the flood discharge resulting from the mega rainfall event scenario was estimated using the Consecutive Storm Event Based (ConSEB) model. The Simplified Dam Break (SMPDBK) model was employed to simulate the dam break. The flood discharge estimated for this scenario amounted to 31,080.34 cms, which is about 1.2 times larger than the Probable Maximum Flood (PMF). The dam break water level simulated by the SMPDBK model was 150 m and the flood damage area was estimated to be 307.45 km2. Based on the results of the study, we highlighted the need to consider continuous rainfall events within EAPs.