- 1Swedish Meteorological and Hydrological Institute, Research and Development, Hydrology, Norrköping, Sweden (david.gustafsson@smhi.se)
- 2Division of Water Resources Engineering, Faculty of Engineering, Lund University
- 3DTU Space, Technical University of Denmark, Kgs. Lyngby, Denmark
- 4DTU Sustain, Technical University of Denmark, Kgs. Lyngby, Denmark
- 5Drone Systems Aps, Aarhus, Denmark
- 6Lobelia, Doctor Trueta 113, 08005 Barcelona, Catalunya
- 7isardSAT, Doctor Trueta 113, 08005 Barcelona, Catalunya
- 8Department of Geosciences and Natural Resource Management, University of Copenhagen, 1958 Frederiksberg, Denmark
In this study we explore the potential to inform a nation-wide high-resolution hydraulic model used for flood risk forecasting, using Unoccupied Aerial Systems (UAS) hydrometry surveys and satellite altimetry. Drone-based data on bathymetry, water surface elevation, slope and discharge was collected along a 50 km flood-prone part of the Torne river, located on the border between Sweden and Finland during a low flow period in September 2024. Cross-section profiles of bathymetry, water surface velocity and elevation were sampled at about 1 km distance. Along river profiles of water surface elevation were collected both with the UAS surveys, as well as from the SWOT satellite mission for the survey period and previous historic data back to April 2023.
The Lisflood-FP model was previously set up at a 5x5 m2 resolution for all rivers in Sweden with an upstream area larger than 50 km2. To make this possible, the model setup was split into around 13000 sub-models based on the existing sub-basin delineation of the hydrological model used for discharge predictions (S-HYPE). Each Lisflood-FP sub-model was calibrated separately using observations of water level along the local river reach derived from the national laser-scanning data and the corresponding discharge predicted by the hydrological model at the dates of the laser-scanning of the area. In most sub-models, this meant that calibration was made using only one set of discharge and water level data. Additionally, several assumptions were made in lack of more information regarding the river bathymetry and downstream boundary conditions.
Based on the UAS and satellite altimetry data, we will demonstrate the potential to improve the previously setup hydraulic model with regard to flood risk assessment, in particular the ability to predict a recent flood event during the spring flood 2023. The UAS and altimetry data is used to improve the representation of river bathymetry, downstream boundary condition (slope), as well as impact of additional along river water surface elevation data for model calibration.
How to cite: Gustafsson, D., Greve Villaro, C., Petersson Wårdh, L., Wennerberg, D., Fagerström, V., Zhou, Z., Damgaard Christensen, F., Nielsen, S., Cendagorta, D., Escorihuela, M. J., and Bauer-Gottwein, P.: Use of UAS and space born hydrometric data to improve flood modelling along the Torne river in northern Sweden, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17836, https://doi.org/10.5194/egusphere-egu25-17836, 2025.
