Hyacinth cover
–
of river surface
Area covered
–
km² of water
Change, ~30 days
–
percentage points
Muddy water
–
of river surface
Hyacinth by river stretch
Worst stretches
Each stretch is about 500 m of river. Select one to zoom.
Hyacinth cover over time
% of river surfaceMuddy water over time
% of river surfaceShow data table
| Date | Hyacinth % (optical) | Hyacinth % (radar) | Hyacinth km² | Muddy % | Cloud-free % |
|---|
How this works
Every few days the European Space Agency's Sentinel-2 satellites photograph the region at 10 m resolution. An automated pipeline downloads each new image, removes clouds and shadows, and checks every water pixel on the river:
- Floating vegetation: water pixels that look strongly green to the satellite (NDVI above 0.3). On Pune's rivers this is almost always water hyacinth, but it can also be weeds on sandbars or overhanging trees at the banks.
- Muddy water: water that reflects more red than green (NDTI above 0.05), a sign of sediment or sewage.
These are satellite estimates, not lab measurements. Narrow stretches under 20 m wide and anything smaller than a pixel (plastic, garbage) cannot be seen. During the monsoon optical images are mostly cloudy, so only the radar estimate continues.
Contains modified Copernicus Sentinel data (Sentinel-1 and Sentinel-2), processed via Microsoft Planetary Computer. River outlines © OpenStreetMap contributors.