The FluViSat project: Measuring streamflow from space with very high resolution Planet satellite video

The measurement of streamflow in the world’s rivers is critical to the management of water as a resource and to predicting and managing the impacts of potentially damaging hydrological events such as major floods. The European Space Agency sponsored FluViSat (Fluvial Video from Satellite) project has successfully demonstrated the potential of very high resolution satellite imagery for the determination of water flow speeds, and hence streamflow rates, using established surface velocimetry techniques.

Video imagery kindly provided by Planet Labs PBC from the 21 satellites in their SkySat constellation was pre-processed to stabilise and georectify it, and then analysed using Space Time Imaging Velocimetry (STIV) techniques to provide water speed vectors across the river’s surface. The method was successfully demonstrated on rivers in Australia, the UK and Africa, with field based validation undertaken where possible. Additionally, a series of six videos was obtained and analysed to provide near a sequence of observations of flood flows on the Indus River in Pakistan during the devastating flooding of 2022.

Benefits of the FluViSat innovation include the ability to observe water flow rates almost anywhere on the planet, the potential for multiple daily repeat observations and largely eliminating the need for locally based people, equipment and infrastructure.

This presentation presents results from the research, explains the methods employed to derive and validate flow speeds, and explores opportunities to further enhance the FluViSat methodology.