Simulating floods triggered by volcanic activities in the Cheon‐ji caldera lake for hazards and risk analysis

Abstract

Many volcanic craters and calderas are filled with large amounts of water that can pose significant flood hazards to downstream communities due to their high elevation and the potential for catastrophic releases of water. Explosive volcanic activity, uplift of the lake floor and landslides directed into the lake are some of the possible scenarios that can cause the release of water through a breach. In this paper, we derive a physically based model that uses the mass balance equation to simulate the hydrograph through a breached rim due to water displacement by lake floor uplift or landsliding. The model was applied to the Baekdusan volcano to examine its performance. Then, the hydrograph at the breach of a caldera lake serves as an upstream boundary condition for the subsequent flood‐routing model, FLO‐2D. The FLO‐2D simulation shows that three populated towns are at risk, showing maximum depth up to 10–30 m. The flow converges to the Baishan dam that has a volume capacity of 6.5 km3. The simulation shows the probable inundation zones and maximum depth, and these are to be used for risk assessment.

Review of Local and Global Impacts of Volcanic Eruptions and Disaster Management Practices: The Indonesian Example

“…At the summit of the volcano, another type of water body is the crater lake and the caldera lake. In turn, the water-bodies can affect the eruptions, with notably the frequent breakout floods from crater lakes that can turn into lahars [46,47]. In Indonesia, access to water is important as in Merdada caldera lake, Central Java, a massive water extraction for agricultural purposes [48].…”

Digital methodology to detect vulnerable areas to flooding in urban zones located in the mountains

“…The models built with this tool provide results for each cross section of the river and the possible water level allowing an analysis of flood events (Gou et al, 2021;Knel et al, 2005). The simulation of scenarios with this tool shows the probable flood zones and maximum depth, and these can be used for risk assessment (Lee et al, 2018). This paper proposes a digital methodology using ArcGIS, HEC-RAS and HEC-GeoRAS based on GIS, to build a map of areas vulnerable to flooding ─risk map─ considering the environmental variables, to simulate flood scenarios in urban communities located in mountain ranges with shallow rivers of rapid response of water flow.…”