Coastal flood depth (Deltares + WRI Aqueduct, combined)
This layer maps how deep coastal flooding could be at a given location for a severe storm-surge event, expressed as inundation depth in metres.
Category: Physical risks · Mitigating services · Climate Acute Risks Coverage: Global (coastal) Format: Raster grid (~90 m) Used in risk analysis: Yes — gates Mitigating services
What it shows
This layer maps how deep coastal flooding could be at a given location for a severe storm-surge event, expressed as inundation depth in metres. It represents a one-in-a-hundred-year coastal flood under present-day conditions. By giving site-level depth rather than a broad category, it helps distinguish exposure within long, low-lying coastal stretches such as deltas and gulf coasts.
How it is built
The layer averages two open global flood-model products on a fine (~90 m) coastal grid: the Deltares Global Flood Maps (using a vegetation- and building-corrected elevation model, 2018, with surge driven by modern reanalysis) and the WRI Aqueduct coastal flood hazard product (historical baseline, no subsidence or flood defences, resampled to the finer grid). Both share the same underlying surge-model lineage but differ in their elevation models and in the vintage of the surge forcing; averaging them yields a middle-ground depth estimate whose extent follows the broader of the two footprints. Wave setup and coastal protection structures such as dykes and levees are not included.
How to read it
Values are inundation depths in metres for a one-in-a-hundred-year coastal flood: higher values mean deeper potential flooding and greater exposure. Because defences and wave setup are excluded, depths are best read as a hazard screening signal rather than a guaranteed local outcome.
Source
Deltares Global Flood Maps (via Microsoft Planetary Computer) and WRI Aqueduct Floods Hazard v2.
Comparison with the WWF Risk Filter Suite
This layer relates to WWF Biodiversity Risk Filter indicator S3_7 Flooding and Water Risk Filter category B3 Flood. WWF expresses flood risk as a catchment-level occurrence-and-hazard composite, whereas Darwin provides a gridded site-level inundation-depth layer that can discriminate within low-lying coastal areas.
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 | Coastal flood mitigation services | Layer value above 1 | “Coastal flood mitigation” pressure ≥ 4 |
Legend
Symbolised field: Coastal submersion risk
| Class | Colour |
|---|---|
| Very low (0–0.5 m) | #fee08b |
| Low (0.5–1 m) | #fdae61 |
| Moderate (1–2 m) | #f46d43 |
| High (2–4 m) | #d73027 |
| Very high (>4 m) | #7b3294 |
Generated from darwin/layers/layer-coastal-flood-depth-deltares-wri-combined.toml and risk_indicator_pairs.toml (develop).