Zoonotic disease spillover risk (global, Allen et al. 2017)
This layer measures the relative risk that new infectious diseases will emerge by jumping from animals to humans (zoonotic spillover).
Category: Physical risks · Mitigating services · Biological hazards Coverage: Global (land only) Format: Raster grid (~5 km, aggregated from a ~100 km source) Used in risk analysis: Yes — gates Mitigating services
What it shows
This layer measures the relative risk that new infectious diseases will emerge by jumping from animals to humans (zoonotic spillover). Areas of higher risk tend to be where conditions favour the emergence of diseases such as COVID-type illnesses. It concerns diseases affecting people rather than agricultural pests, and helps flag locations where biological hazard is comparatively elevated.
How it is built
The layer is based on Allen et al. (2017), a published global model that predicts a relative-risk surface for emerging zoonotic diseases at roughly a 100 km grid, adjusted for differences in disease-reporting effort and for human population demographics. Following WWF rules, the underlying risk is summarised per river-basin unit (HydroBASINS Level 7 catchments), taking the maximum value within each, and basins are then grouped into five classes by their relative ranking. The classified result is presented as a finer global grid; oceans carry no value. It is intended as a screening layer.
How to read it
The layer uses a five-class scale: very low, low, moderate, high and very high. Higher classes indicate areas where the modelled likelihood of a new animal-to-human disease emerging is greater; lower classes indicate comparatively low risk. A site is assessed by the class of the area it falls within.
Source
Allen, T. et al. (2017), "Global hotspots and correlates of emerging zoonotic diseases", Nature Communications 8:1124, doi.org/10.1038/s41467-017-00923-8. Aggregation units from HydroBASINS / HydroSHEDS (Lehner & Grill 2013, CC-BY).
Comparison with the WWF Risk Filter Suite
This layer maps to BRF S3_3 Disease and is aligned: it uses the same Allen et al. (2017) zoonotic-spillover surface that WWF references for this indicator.
Risk analysis
A site is flagged on a dimension by combining a proximity trigger (this layer) with an activity trigger (the entity's ENCORE pressure/service). Proximity only → Potentially material; proximity and the matching ENCORE pressure/service is material → Very material; neither → Not material.
| Dimension | ENCORE service / pressure | Proximity trigger (this layer) | Activity trigger (entity) |
|---|---|---|---|
| Mitigating services | Disease (zoonotic spillover) | Layer value above 4 | — |
Legend
Symbolised field: Zoonotic spillover risk
| Class | Colour |
|---|---|
| Very low | #ffffcc |
| Low | #d9f0a3 |
| Moderate | #fdae61 |
| High | #f46d43 |
| Very high | #d73027 |
Generated from darwin/layers/layer-zoonotic-spillover-global.toml and risk_indicator_pairs.toml (develop).