Abstract Monitoring small rivers during extreme events is challenging, especially in remote areas. This study assesses the accuracy of the Surface Water and Ocean Topography (SWOT) mission in characterizing an extreme hydrological event on a narrow river (∼60 m wide), using a landslide‐induced flood on the Chilcotin River (Canada) as a case study. SWOT data, validated against optical imagery and elevation data sets, were used to estimate water surface elevation and slope changes. SWOT was able to detect lake impoundment, dam breach, and downstream slope adjustments induced by the landslide. Results suggest the utility of SWOT's spaceborne interferometric data to quantify spatial and temporal impacts of extreme events on river dynamics, even for small and narrow rivers.
Plante et al. (2026) studied this question.