🌡️ Why this matters — Urban Heat Island
+2.7°C
Hyderabad LST rise 2015–2024
50°C+
Projected Indian city temps by 2035
7.1M
Buildings mapped across 5 cities
40%
Urban heat absorbed by buildings
Every building that goes up without green cover adds to the Urban Heat Island effect. VertiGreen identifies which buildings contribute most to UHI — at individual building resolution — using real satellite data. Nobody has done this at 7.1 million building scale for Indian cities before.
🏗️ What this tool does
VertiGreen is a building-level geospatial analysis tool that:
• Maps solar heat exposure per wall using sun position mathematics (6am–8:30pm full-day weighted)
• Calculates shadow analysis to identify which walls are naturally shaded — and therefore best suited for vertical gardens
• Estimates Land Surface Temperature using NASA MODIS satellite data (1km resolution, daily updates)
• Predicts cooling impact of vertical gardens using physics-based LAI, albedo and evapotranspiration models
• Calculates rainwater harvesting potential using IMD annual rainfall data and NBC 2016 runoff coefficients
• Checks bylaw compliance against National Building Code 2016 FAR limits
🛰️ Data methodology & limitations
"LST and NDVI values are sourced from NASA MODIS satellite data where available. In cases of API unavailability, values are estimated using a physics-based model calibrated to Indian climatic zones. Greening impact predictions use LAI, albedo and evapotranspiration factors from published literature (Pérez et al. 2011, Alexandri & Jones 2008)."
Land Surface Temperature (LST) Real when availableEstimated as fallback
Source: NASA MODIS MOD11A1 (1km resolution, daily). When NASA API is unavailable, LST is estimated from latitude + season + urban density formula calibrated to Indian cities.
NDVI Vegetation Index Real when availableEstimated as fallback
Source: NASA MODIS MOD13A2 (1km, 16-day composite). When unavailable, estimated from 0.05–0.25 based on urban density. Used to correct wall heat exposure for surrounding vegetation.
Wall Temperature Approximate
Calculated as: LST + (wall_exposure × 15). The ×15 multiplier is approximate — real values depend on wall material, colour, orientation and albedo which are not available in building footprint data.
Greening Cooling Effect Research-based estimate
LAI factor −35%, albedo factor −15%, evapotranspiration −20% — from published ranges (Pérez et al. 2011). Not building-specific measurements. Actual cooling varies by plant species, coverage density and climate.
UHI Offset Rough approximation
Estimated as: 3 + wall_exposure × 3. Real UHI measurement requires weather station data and neighbourhood-level density analysis not yet integrated in this version.
Solar Azimuth & Shadow Mathematically precise
SunCalc algorithm — peer-reviewed solar position formula. Shadow polygon = building height / tan(solar altitude) in the direction opposite to sun azimuth. Accurate to ±1° for Indian latitudes.
Wind Direction & Speed Live data
Source: Open-Meteo API (free, no key). Real-time wind from nearest weather station. Diurnal pattern (calm dawn → peak midday → calm night) applied based on thermal convection science.
🏛️ Government schemes — where this tool fits
🏙️
AMRUT 2.0 — Urban Greening Component
₹66,750 crore scheme with explicit urban greening mandate. VertiGreen can identify high-impact buildings for targeted subsidy allocation rather than random distribution.
🌆
Smart Cities Mission
100 cities, active greening budget. Building-level heat maps from VertiGreen can directly feed into Smart City project planning documents.
🌳
CAMPA Funds — Compensatory Afforestation
Vertical greening on buildings could qualify as urban forest equivalent. VertiGreen provides the data to make that case building by building.
🏗️
RERA & NBC Compliance
If NBC 2016 mandates green walls for new construction above 10 floors, VertiGreen becomes a compliance verification tool. Already checks bylaw height compliance.
💰
Cost reality of vertical greening
Installation: ₹800–2,500/sq ft. Typical 100m² wall: ₹8–25 lakhs. Annual maintenance: ₹1–3 lakhs. Government subsidy of even 40% would unlock widespread adoption in metro cities.
📖 References
• Pérez G. et al. (2011). Green vertical systems for buildings as passive systems for energy savings. Applied Energy.
• Alexandri E. & Jones P. (2008). Temperature decreases in an urban canyon due to green walls and green roofs in diverse climates. Building and Environment.
• IMD (2023). District-level rainfall normals 1991–2020. India Meteorological Department.
• BIS (2016). National Building Code of India. Bureau of Indian Standards.
• Wan Z. (2014). New refinements and validation of the collection-6 MODIS land-surface temperature/emissivity product. Remote Sensing of Environment.