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Methodology · public

The science behind every avoided-cost number.

Urban Cat is a glass box. Every coefficient, dataset and discount rate is named, dated and traceable to a peer-reviewed paper or government appraisal guide. Click any metric for the two-sentence theory and the DOI.

ESA Copernicus

Sentinel-2 L2A

10 m surface reflectance composites for NDVI, land-cover and canopy delta. Updated every 5 days.

ODbL

OpenStreetMap

Building footprints, road network, parcel geometry. Snapped to local cadastres where available.

Reanalysis

Open-Meteo · ERA5

1991–2020 climate normals: temperature, rainfall, cooling-degree-days, mean radiant temperature.

Open data

GBIF

Verified species occurrence records aggregated within a 2 km buffer of the project polygon.

CC-BY-NC

iNaturalist

Research-grade citizen-science observations cross-referenced with GBIF for pollinator scoring.

Metric glossary

Click any metric for the two-sentence theory

UTCI
Universal Thermal Climate Index — what the body actually feels.
NDVI
Normalised Difference Vegetation Index — satellite-derived greenness.
EVI
EVI — NDVI's denser, less-saturating sibling for thick canopy.
SCS-CN runoff
Curve-number method for storm runoff depth from rainfall.
HSG
Soil drainage classification A (sandy) to D (clay).
BNG units
Statutory biodiversity uplift unit (UK Environment Act 2021).
ELR
Ecological Loss Ratio — habitat lost per unit of project footprint.
Avoided cooling cost
Energy bill avoided by canopy and high-albedo cover.
Avoided stormwater cost
Treatment + flood damage avoided per year.
Sequestered carbon
Above- and below-ground biomass capture, monetised.
WELLBY social value
Wellbeing-adjusted Life Years from green-space access.
PES
Annual payments for the public benefits a green scheme delivers.
PM2.5
Sub-micron particles that lodge deep in the lungs.
NO₂
Roadside traffic pollutant, irritates airways.
NPV
Today's value of all future cashflows, discounted.
IRR
Discount rate at which NPV = 0 — the scheme's effective % return.
BCR
PV of benefits ÷ PV of costs.
LCOE
All-in cost per unit of outcome delivered.
DCF
Year-by-year cashflow run with a discount rate applied.
EAC
Capex + opex spread evenly across the asset life.
TCO
All money spent over the asset life — capex + lifetime opex.
AAL
Probability-weighted £ loss per year from a peril.
CVaR
NPV at risk under a stressed climate scenario.
RCP4.5 / RCP8.5
IPCC climate scenarios — RCP4.5 stated-policy; RCP8.5 stress test.
TCFD
Mandatory UK climate-risk disclosure framework.
IFRS S2
Global accounting standard for climate-risk reporting.
ICVCM CCP
Quality bar for voluntary carbon credits.
MRV
Standard 3-step proof loop for any environmental claim.
TNFD LEAP
Locate / Evaluate / Assess / Prepare — the nature-risk disclosure loop.
Monte Carlo (n=800)
Probabilistic uncertainty across 800 parameter draws.
NSGA-II Pareto optimiser
Multi-objective genetic search for the trade-off frontier.
GAN super-resolution
AI upscaler that sharpens 10 m satellite tiles to 1 m for print.
IMD decile
Decile 1 = most deprived 10% of LSOAs; 10 = least.
© Urban Cat · Methodology revisions are version-tagged in Engine Room release notes.