Every satellite pass, against the rain
Pick a pass to see it on the map. Clouds hid the ground from 27 October until PlanetScope's cloud gaps on 1 November. Only radar saw through on 30 October.
Before and after, same ground
Drag the handle. On 1 November the stream below Tadama shows pale and scoured, with red-brown silt at Baiballi.
Where to look
Ten places, best lead first. The map follows as you scroll.
Homes and roads in harm's way
Each building was checked against radar changes, debris paths, low ground beside streams, and slope risk.
Buildings
Roads
Settlements to check first
How we read it
What a sudden radar drop means
A drop of 3 dB means about half the signal is gone. The surface changed between two passes: trees lost, or ground covered by mud or water. Radar alone cannot separate mud from water, so we use terrain, drainage size and optical images too.
Does the signal stand out?
Steps
- Radar Six Sentinel-1 passes, terrain corrected, 10 m. Bad radar angles removed.
- Change 30 Oct against five earlier passes, with wide-area wetness removed.
- Terrain DEM slope, drainage, catchment and height above stream sort slope failure from flood.
- Optical Sentinel-2 and PlanetScope quick views, including the 1 Nov cloud gaps.
- Exposure 51,418 building footprints and road sections tested against each hazard.
PlanetScope passes over the site
PlanetScope views here are quick looks at about 70 m. Full 3 m images of 22 October and 1 November would show the village itself.