Author(s): Moritz Roth; Ryota Tsubaki; Nils Ruther
Linked Author(s): Nils Rüther, Ryota Tsubaki
Keywords: Turbidity bathymetry unmanned aircraft systems (UAS) remote sensing river
Abstract: *Preliminary abstract, as the data will be collected in March 2025. * The accurate modeling of bathymetry in natural river channels is essential for understanding hydraulic processes, sediment transport, and ecosystem dynamics. Unmanned Aerial Systems (UASs) have emerged as a promising tool for bathymetry acquisition due to their ability to capture high-resolution imagery. In order to reconstruct a 3D structure from 2D images, the Structure from Motion (SfM) photogrammetric technique is used. Although 3D detection of dry earth surface is an established state-of-the-art procedure based on stereo photogrammetry technique, methods for the reconstruction of the underwater areas are still under development. Bathymetry in the water-covered areas can be detected theoretically using known water surface elevations in the study area taking into account the refractive index of light in water. Using this approach in the past, authors were able to acquire bathymetry with accuracy sufficient for most hydraulic engineering applications for multiple river reaches. However, the impact of determining bathymetry in turbid waters using UAS imagery acquired with low-cost technologies has not yet been fully investigated. Therefore, the study focuses on investigating the relationship between water turbidity and bathymetric reconstruction accuracy of underwater areas in a trapezoidal channel using UAS images captured with RGB and multispectral sensors.
Year: 2025