Surface Deformation Analysis following Tropical Cyclone DITWAH-25 in Sri Lanka (2025-11-27)

On 27 November 2025, Tropical Cyclone DITWAH-25 struck Sri Lanka, triggering widespread flooding, as well as landslides and mudslides in several districts, particularly in the selected locations of Matale and Kandy. The cyclone caused extensive damage to houses and critical infrastructure, and resulted in casualties.

The objective of the current activation is to derive and analyse ground deformation from satellite Synthetic Aperture Radar (SAR) observations in the most affected districts of Matale and Kandy, in order to identify areas of measurable ground movement before, during and after the November 2025 event.

The results are intended to provide a scientific basis for prioritising field investigations and to support geologists and local authorities in validating and refining on-site observations, with particular attention to deformation patterns consistent with rainfall-triggered slope instability and potential landslide reactivation.