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Light Pollution
Light Pollution
Light Pollution
Light Pollution
Light Pollution
Risksv03.00 credits/per_km2
Responsible:Niccolò Calandri
Layer Light Pollution on real sites
Real Estate UK
Catania
Berlino Quarter
Mina el Cerrejon
Light Pollution
Overview
Light pollution measures the intensity of artificial night light emitted by roads, buildings, signs and other anthropic elements, expressed in nanowatts per square centimetre per steradian (nW/cm²/sr). It represents one of the primary stressors for natural ecosystems: artificial night light disrupts the circadian rhythms of animals and plants, interferes with insect navigation (particularly nocturnal Lepidoptera), disturbs the reproduction of migratory birds, and alters plant phenology.
Ecosystems exposed to high levels of artificial night light exhibit reduced nocturnal biodiversity, altered food webs, and impoverishment of night-related ecosystem services (nocturnal pollination, predation, decomposition). The KPI is inverted: lower radiance values indicate more favourable conditions for biodiversity.
Calculation Methodology
The calculation uses the VIIRS Day/Night Band Monthly dataset (NOAA/NASA) at 500 m resolution, which captures the spectral radiance of the Day/Night Band (DNB) of the VIIRS sensor aboard the Suomi NPP satellite.
The calculation process involves the following steps:
- Monthly acquisition — collection of monthly VIIRS DNB images for the period 2012–2025
- Quality filtering — exclusion of acquisitions with high cloud cover or lunar disturbances
- Spatial averaging — calculation of the mean radiance value (nW/cm²/sr) across all pixels within the polygon
- Temporal aggregation — annual or monthly average depending on the required granularity
Unit: nanowatts per square centimetre per steradian (nW/cm²/sr)
Visualisation: colour gradient from dark blue (low pollution) to yellow (high pollution)
Data Sources
| Code | Name | Provider | Resolution | Availability |
|---|---|---|---|---|
WRD_VRDNB_99 | VIIRS Day/Night Band Monthly | NOAA / NASA | 500 m | 2012 — 2025 |
Quality Range and Levels
| Indicator | Unit | Range | Inverted |
|---|---|---|---|
light_pollution | nW/cm²/sr | [0, 5, 30, 60, 90, 120] | Yes |
Inverted = Yes: a higher radiance value indicates greater light pollution and worse conditions for nocturnal biodiversity.
| Level | Radiance (nW/cm²/sr) | Interpretation |
|---|---|---|
| E (Critical) | > 90 | Extreme light pollution; heavily urbanised area; nocturnal fauna severely impaired |
| D (Poor) | 60 – 90 | High light pollution; dense urban peripheries; significant disruption of natural cycles |
| C (Moderate) | 30 – 60 | Moderate light pollution; peri-urban areas; partial impact on nocturnal fauna |
| B (Good) | 5 – 30 | Low light pollution; rural areas with infrastructure; limited impact |
| A (Excellent) | 0 – 5 | Near-natural dark sky; optimal conditions for nocturnal fauna and astronomical observation |
Technical Notes
- VIIRS DNB values include light reflected from surfaces (snow, residual clouds) which may overestimate the signal in certain periods
- The VIIRS sensor replaced DMSP/OLS from 2012 with improved radiometric sensitivity and spatial resolution
- Seasonal variability (e.g. snow, vegetation) can influence monthly values; annual averages are recommended for inter-annual comparisons
- In areas with gas flares (oil installations) values may be artificially elevated
References
- Falchi, F., Cinzano, P., Duriscoe, D., et al. (2016). "The new world atlas of artificial night sky brightness". Science Advances, 2(6), e1600377.
- Gaston, K.J., Bennie, J., Davies, T.W., Hopkins, J. (2013). "The ecological impacts of nighttime light pollution: a mechanistic appraisal". Biological Reviews, 88(4), 912–927.
- Cinzano, P., Falchi, F., Elvidge, C.D. (2001). "The first world atlas of the artificial night sky brightness". Monthly Notices of the Royal Astronomical Society, 328(3), 689–707.
Quality Ranges and Levels
light_pollution
(nW/cm²/sr)ACritical
BLow
CModerate
DGood
EExcellent
0 → 4.99
5 → 29.99
30 → 59.99
60 → 89.99
90 → 120
A
Critical0 – 4.99B
Low5 – 29.99C
Moderate30 – 59.99D
Good60 – 89.99E
Excellent90 – 120Data Sources & References
Sources
WRD_VRDNB_99
Methodology
VIIRS Day/Night Band Monthly dataset (NOAA/NASA, 500 m, 2012–2025). Monthly acquisitions of the DNB spectral radiance from the VIIRS sensor (Suomi NPP). Quality filtering: exclusion of acquisitions with high cloud cover or lunar disturbances. Spatial mean radiance (nW/cm²/sr) across all pixels in the polygon. Annual or monthly temporal aggregation. Colour gradient: dark blue (low) → yellow (high pollution). Inverted indicator: lower values = less pollution = better for nocturnal biodiversity.