Flood risk assessment in vegetated lower Asahi River of Okayama Prefecture in Japan using airborne topo-bathymetric LiDAR and depth-averaged flow model

•We used airborne topo-bathymetric LiDAR to obtain both vegetation and bed data.•A LiDAR point cloud was used to assess flow resistance in vegetated flooded rivers.•The proposed method was checked using Asahi River flooding simulations.•Results demonstrate that the method estimates the distributed flow resistance well.•These reported findings can support flood control work design for vegetated rivers.