Satellite analysis for India — read any lake, ward or city from space
Dyaan turns free, public satellite and open geospatial data into plain-language answers about any place in India you can draw on a map. No API keys, no invented numbers — every figure is measured from real satellite pixels and can be reproduced in the tool. It works for Bengaluru, Chennai, Delhi, Mumbai, Hyderabad, Pune, Kolkata, Ahmedabad and every town, tank and village in between. If you have ever needed a defensible number about a lake, an encroachment, a flood-prone ward or a city's shrinking green cover — and did not want to wait weeks or pay for a survey to get it — this is built for you.
What you can measure across India
- Lake & tank water quality — chlorophyll (algae) and turbidity over any Indian lake from Copernicus Sentinel-2, with a multi-year trend. Built for lake-revival groups and RWAs tracking Bengaluru's lakes or Chennai's eris.
- Encroachment checks — built-up land inside a lake, park or protected boundary, cross-checked across ESA WorldCover, OpenStreetMap building footprints and JRC water history for a confidence-rated read, not a single-sensor guess.
- Flood exposure — the low-lying ground monsoon runoff collects toward, from the 30 m Copernicus DEM, corroborated with where surface water has historically pooled.
- Green-cover & vegetation change — NDVI now and over time, to see a city's tree cover gained or lost between any two years.
- Garbage & dumping hotspots — landfills and open dumps, flagged by OpenStreetMap tags and NASA FIRMS burning detections, since Indian dumps are routinely set alight and show up as heat.
- Surface-water change (1984–2021) — how a city's lakes and reservoirs have grown or vanished across nearly four decades of the JRC Global Surface Water record.
A worked example: Bengaluru's lake belt, measured
Take the Bellandur–Varthur belt in south-east Bengaluru — the city's most talked-about water bodies. Point Dyaan at it and it reads the JRC Global Surface Water archive pixel by pixel from 1984 to 2021. The headline number from our own Bengaluru field note is a net gain of 59 hectares of surface water across the period — not the story most people expect, and exactly why a measured number matters more than an assumption. The gain is real (sewage-fed tanks and reservoir operation hold water that seasonal lakes once lost), but it says nothing about quality — which is where the Sentinel-2 chlorophyll and turbidity read comes in, and where the frothing, algae-choked surface everyone photographs actually shows up. One tool, two independent measurements, no guessing. Delhi tells a different story again: our Delhi field note measures a net gain of 311 hectares of surface water over the same window, driven by the Yamuna floodplain and new reservoirs. Every one of these figures is counted, dated and reproducible.
City by city
Bengaluru — lake water quality and encroachment are the daily fight here; Dyaan reads Bellandur, Varthur, Rampura, Ulsoor and any tank you draw, and flags built-up creep inside their historical boundary. Chennai — the eri (tank) network and post-monsoon flooding: screen which low ground fills first and watch tanks silt up or get built over. Delhi — Yamuna floodplain change, green-cover loss across the ridge, and winter dust over water. Mumbai — mangrove and wetland loss along the creeks, and the low-lying wards the tide and monsoon reach. Hyderabad — the shrinking of the city's iconic lakes (Hussain Sagar and the smaller tanks) and cropland turning to concrete on the fringe. The method is identical everywhere — draw the area, read the record — so the same trust applies to a metro and to a village pond.
What you can and cannot see
Honesty is the product. Optical satellites read the surface at 10 m per pixel (Sentinel-2) and the long water archive at 30 m (JRC), so a pond smaller than a few pixels is an indicative flag, not a survey. Chlorophyll and turbidity are calibrated optical proxies, not a lab assay — they tell you where and when algae builds up so you know which water to sample first. Clouds hide the surface, so a reading is the best recent clear view, always shown with its date. Dyaan states these limits on every result rather than hiding them, and points you to a ground check when one is warranted. That is the difference between a number you can defend to a corporator or a court and a number you cannot.
Who uses it in India
Citizen groups and lake activists building the case to save a water body; resident welfare associations and corporators documenting encroachment or garbage; journalists and researchers who need a figure they can defend on deadline; students and NGOs who cannot afford commercial imagery; and anyone who wants a fast, free, honest read on their neighbourhood before commissioning a survey.
Questions
Is satellite analysis for India really free?
Yes. Dyaan runs entirely on free, keyless public archives — Sentinel-2, JRC Global Surface Water, NASA FIRMS, ESA WorldCover and the Copernicus DEM — so there is no cost to read any Indian location. Only optional high-resolution image downloads are a paid add-on.
Which Indian cities does it cover?
All of them, and everything between. There is no pre-built list — you draw any area on the map, from a single tank to a whole metropolitan region, and Dyaan reads the satellite record for exactly that ground.
Can I use the numbers in a report or petition?
Yes — every figure is measured, dated and traceable to a named public dataset, and every result table exports to CSV or GeoJSON. See the methodology for how each number is derived.
How current is the data?
Active-fire and recent imagery refresh within about a day; the multi-decade water and land-cover archives are the latest published versions. Every reading shows the date it was read.
Analyse a place in India now — free
Read the worked field notes: Bengaluru's lakes · Delhi's surface water · all field notes.