Comparison of FLUMEN and HEC-RAS 2D Models for Flash-Flood Inundation Considering Land Cover and Building Presence

The increased frequency and intensity of floods caused by climate change has exacerbated damage in urban areas. Flood-inundation maps, which is a nonstructural measure, is crucial in preventing and mitigating such damage. Two-dimensional flood-analysis models, such as FLUMEN and HEC-RAS 2D, are widely used to simulate urban flooding caused by complex factors such as buildings, land cover, and terrain. This study aims to compare the simulation results of FLUMEN and HEC-RAS 2D by considering land cover and building presence in a specific urban area. By comparing the simulation results under various roughness coefficients and the presence or absence of buildings, the uncertainties arising from model selection are examined, which highlights the importance of selecting an appropriate model for urban areas. The results of this study contribute to the decision making involved in selecting suitable numerical models for various urban-flood scenarios. In the future, a systematic approach must be established for selecting flood-analysis models and expanding their functionality through integration with hydrological models.