Proposal of digital twin approach in cooperation with flood analysis for small and medium rivers

The purpose of this study is to propose a digital twin approach that supports evacuation actions in conjunction with flood analysis. In order for local residents to properly understand evacuation sites and evacuation routes and to take action before floods occur, it is necessary to provide content that enables them to experience the situation near and behind river channels, and to provide content that shows the hydraulic phenomena leading to floods in chronological order. In this study, we used 3D point cloud data obtained by laser survey of the Chiribetsu River in Muroran City, Hokkaido, Japan, to represent river channel topography, Fundamental Geospatial Data for the hinterland, and PLATEAU for buildings, and calculated hydraulic phenomena such as river water level and flood depth to create a time series of flood damage using iRIC Nays2D Flood. This paper proposes the hazard map image reproduced on the digital twin by adding evacuation place and route. We believe that this kind of content, which provides a realistic picture of the actual situation of flood disasters, will help local residents take appropriate evacuation actions.