For city corporations
Tawi Twin is a monsoon and heat command layer for an Integrated Command & Control Centre: building-level
risk, live alerts, where to send pumps, which drains to clear, and a citizen channel with AI triage. Every input
is free global data, so a new city can be onboarded in a day.
What changes, and for whom
A resident in Gujjar Nagar asks in Hindi “kal paani bharega?” and gets a yes/no for the next 48 h,
why, what to do, and the nearest hospital and high-ground school. One tap shares it on WhatsApp.
The control room sees which areas and how many buildings are at risk before the rain, where to
pre-position dewatering pumps, which drains to clear first, and citizen photos already triaged by AI.
The planning wing gets a ranked pre-monsoon list of drains and areas, weighted by how many
people live there, as a CSV.
Does it match what happened?
We checked 8 localities that news reports named as flooded on 26–27 Aug 2025 (inside the mapped area).
Near them, 36% of buildings are rated high or very high flood exposure, against 25% city-wide
(1.5×); for “very high” it is 2.9% vs 0.8%. Nikki Tawi, Beli Charan and Bhagwati Nagar are clear hits.
Gurkha Nagar, Qasim Nagar and Rajiv Nagar are misses: the 30 m terrain model includes buildings, and the
radar passed a day after the peak. Small sample: a sanity check, not an accuracy figure.
Sources: Onmanorama,
Sphere India SitRep,
News On AIR.
The event behind it
On 26–27 Aug 2025 Jammu received a record 296 mm of rain in 24 hours, the Tawi
crossed its highest flood level and part of the 4th Tawi Bridge at Bhagwati Nagar gave way.
Evidence
- Flood: Sentinel-1 radar, 27 Aug 2025 18:34 IST vs 15 Aug (change detection, OpenCV).
- Terrain: Copernicus DEM 30 m, height above nearest drain.
- Buildings: 188,180 footprints, Overture Maps (AWS Open Data). Heights are a uniform 6 m (not in source).
- Heat: Landsat 8/9 surface temperature, Apr–Jun 2024–26.
- Land change: Sentinel-2, 2019-20 vs 2025-26, in the flood-prone zone.
- Forecast: Open-Meteo, refreshed hourly.
Limits
Radar misses water between buildings. The flood-prone zone is a proxy, not the official demarcation. Drains are
those mapped in OpenStreetMap only. Land-cover change is detected change, not a finding of encroachment.
Not an official warning: follow JMC, SDMA and IMD. Emergency: 112.
Built on AWS
CloudFront + S3 (site, vector tiles, photos) · API Gateway + Lambda on Graviton · DynamoDB · EventBridge
Scheduler · Amazon Bedrock with Strands Agents (chat + photo triage) · Amazon Location Service · AWS Open Data.
Deployed with AWS SAM. Map: Mapbox.
Data: © OpenStreetMap contributors, Copernicus (ESA), USGS Landsat, Overture Maps, Open-Meteo (CC BY 4.0).