Extreme Precipitation Risk 2050 (France, DRIAS)
This is a forward-looking scenario layer for France.
Source: DRIAS (Météo-France) TRACC2023 Year: 2050 Category: Physical risks · Mitigating services · Climate Acute Risks Coverage: Country (France) Format: Raster grid Used in risk analysis: No (contextual layer; not used in materiality scoring)
What it shows
This is a forward-looking scenario layer for France. It measures how intense the heaviest single-day rainfall is projected to become around the 2050 horizon, helping anticipate where heavy rain will most threaten people, property, farmland and infrastructure through flooding and erosion.
How it is built
The layer reports the projected annual maximum daily precipitation (the wettest single day of the year). It is based on the French DRIAS TRACC2023 climate projection for the ~2050 horizon, at a +2°C global warming level (roughly +2.7°C over France). As a single-model scenario projection, it should be read as a plausible future trajectory rather than an observation. The highest values fall in the Cévennes, the southern Alps and Corsica.
How to read it
Higher values mean more intense projected daily rainfall and therefore greater exposure to flash floods, landslides, soil erosion, infrastructure damage and waterlogging of crops. Lower values indicate milder projected extremes.
Class thresholds
The underlying layer models a physical flux: the projected annual maximum daily precipitation (Rx1day), in millimetres per day (mm/day) — the wettest single day of a typical year. It is rendered as a continuous colour ramp over the range 28 to 176 mm/day rather than as discrete risk classes, so there is no five-class break table:
| Reading | Max daily precipitation (mm/day) |
|---|---|
| Lower end of the ramp | ≈ 28 |
| Risk-flag threshold | 100 |
| Upper end of the ramp | ≈ 176 |
A site is flagged on the Mitigating-services dimension when the projected wettest-day total reaches ≥ 100 mm/day (DRIAS TRACC2023, +2 °C global warming level).
How these thresholds were set. The underlying Rx1day quantity comes from the DRIAS TRACC2023 projection (Météo-France; model CCLM4-8-17 / MPI-ESM). The single 100 mm/day risk-flag cutoff is a Darwin in-house classification — a fixed round-number threshold for an intense-rainfall day — not a published DRIAS class break.
Source
DRIAS – Les futurs du climat (TRACC2023 experiment) — https://www.drias-climat.fr.
Comparison with the WWF Risk Filter Suite
The WWF Risk Filter Suite does not publish a dedicated extreme-precipitation indicator, and this layer is in any case a France-specific, forward-looking 2050 projection. It is a national scenario extension with no distinct WWF equivalent.
Legend
Symbolised field: Max daily precipitation (mm)
Generated from darwin/layers/layer-extreme-precipitation-risk-2050-france-drias.toml and risk_indicator_pairs.toml (develop).