Flood Affected Building Footprints 3D Model from LiDAR and Aerial Photogrammetry (Case Study: Pandugo Street, Surabaya)

Abstract

Frequent rainfall events in Surabaya occurred due to tall silt within the channel, which prevent water flow and at that point flooding onto the street. Information about the events, including the simulation and prediction are needing accurate visualization to be major consideration for infrastructure and public facilities decision-making. 3D modelling are accurate enough as flood disaster risk management for buildings, using LiDAR and aerial photogrammetry that can provide strong visual representations accurately. DSM and DTM derived from aerial photogrammetry survey are then used to get DSM LiDAR. DSM&DTM from LiDAR was taken in 2016 and DSM&DTM from aerial photogrammetry was taken in 2022. The only objects that are updated are buildings from DSM aerial photogrammetry then applied to DSM LiDAR. Buildings footprint, road network, nDSM, and flood inundation data are then processed to get the 3D Model of buildings and floods. The model are then evaluated by comparing the total of affected buildings with manual methods. Validation on buildings height also performed and results in 0.86233 RMSe that achieved the LOD2 standard. Potential further studies could focus on improving the LOD and considering other parameters such as rainfall data or gutter data.