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Loading 3D relief and NASA–ISRO NISAR satellite passes
Taquari Valley, Brazil · July 2026 flood
A radar in space sees through clouds and in the dark. We turn what it sees into simple pictures: we compare Lajeado and its region before and after the flood to show how far the water reached and its many impacts and changes on the planet.
- Where
- Lajeado and region
- What we compare
- before × after the flood
- Back over the same place
- every 12 days
How it works
From space to your street, in four steps. Drag the line on the drawing to compare before and after.
Step 1 of 4
The satellite passes over
NISAR, from NASA and India's space agency, flies 747 km up and passes over the same place every 12 days.
It repeats the same path and the same angle, so two radar pictures can be compared as if taken from the same spot.
What you can see and how far we can expand
See what is already active today on the Taquari Valley map (with real radar, 3D relief, rainfall and land-cover data) and how the platform scales with new data and live integrations.
- Active on map
Water and floods
Where the Taquari River went beyond its normal banks and where new water sheets appeared across floodplains and low ground.
On the map today: Before vs. After patches (NISAR GCOV), crossed with 40-year water history (JRC), daily rainfall (CHIRPS), river level (SGB) and municipal boundaries (IBGE). - Active + Expanding
Plants and crops
Where agricultural or forest cover changed its radar behavior after extreme rain across the valley.
On the map today: automatic crossing with land cover (ESA WorldCover 10 m — 34.2% of patches on cropland and 30.5% on riparian trees) plus radar echo increase or drop. - Active + Expanding
Slopes, relief and hills
What happens across the higher, steeper parts of the valley when heavy rain hits the hills.
On the map today: 3D relief and slope in degrees (Copernicus DEM 30 m, from 18 m to 58+ m) + hillslope surface roughness change (spot Q6). Next step: InSAR phase (GUNW).
How far can we expand SurfaceSignal?
Our foundation already processes real NISAR satellite passes and official environmental layers. Here is what we deliver today and where we can go next:
Water, crops, 3D relief and hillslope roughness
Interactive inspection across squares Q1 to Q6 with real satellite imagery, 3-day rainfall (CHIRPS), river bulletin (SGB), elevation/slope (Copernicus 30 m) and slope texture.
Real-time Taquari River level
Connect the map to real-time telemetric river gauges (SGB/ANA and existing regional monitoring projects in the Taquari Valley), tracking rising water hour by hour alongside satellite patches.
Landslides and millimeter-scale slope movement
Today the GCOV product shows where hillslope surface texture changed. With interferometric phase (NISAR L2 GUNW), we will measure millimeter-scale ground displacement to warn of hillside risks.
Critical infrastructure and elevation-safe routes
Automatically cross flood stage and 30 m elevation relief with hospitals, schools, bridges (such as BR-386) and safe evacuation routes over higher ground.
Radar + High-Resolution Optical Before/After Photos
Combine radar (which sees through clouds during the storm) with optical imagery (Sentinel-2 / Planet) as soon as skies clear, visually confirming every inspection square.
From Lajeado and Estrela to any river basin
Because NISAR revisits the entire planet every 12 days (240 km swath, day and night), the same pipeline can monitor other basins across Brazil and the world.
What we have for this region
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Where the data comes from
Everything here comes from public sources. Nothing is made up: what is still an example is labelled.
Other sources assessed
A registered source has not necessarily been used in this comparison.
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NISAR satellite
NASA and ISRO (India's space agency)
A radar launched in 2025. Its files are public and distributed by NASA's Alaska Satellite Facility (ASF).
River status
Geological Survey of Brazil (SGB)
Official bulletins of the Taquari River level, used to know how the river was close to the time of the pass.
Place outlines
IBGE (Brazil's statistics institute)
Outlines of Brazil and Rio Grande do Sul, under an open licence.
Map and relief
OpenStreetMap, OpenFreeMap and Terrain Tiles
Streets, names and the 3D relief. Free, made by communities and open projects.
Common questions
Why did we make this site?
Our challenge is to show the changes a satellite sees on the surface of a region in a simple way anyone can understand. We chose the Taquari Valley because the river has overflowed several times in recent years and many people, especially older adults and deaf people, do not get or do not understand warnings and technical maps. Hence large letters, plain colors and no technical terms.
How can a satellite see through clouds?
It uses radar, not an ordinary camera. The radar sends its own signal and listens to the echo. Clouds and rain do not block that signal, and it works at night too.
Do you plan to cover other regions and countries?
Yes. That is why the map starts on a globe: the whole world is already there, with other countries, states and regions marked as “coming soon”. The NISAR satellite observes almost all of the planet's land every 12 days, so the same method can be taken to other places.
Who made this site?
Team Sudo Nova, for the NASA Space Apps Challenge 2026. It is not an official NASA or ISRO product.
If there is a flood
This site is not an official alert. If you are in danger in Brazil, get help now:
- 199Civil DefenseCall for danger, shelter and guidance.
- 193Fire DepartmentCall for rescue and emergencies with people.
- 40199Alerts by text messageText your street's postal code (CEP) to get Civil Defense alerts on your phone. It is free.
Share with people who live in the Valley
Send it to family and neighbours. The more people understand what the satellite saw, the better.