Loss of soil and sediment retention

Loss of soil and sediment retention

Plant cover and healthy soils hold land in place when it rains. When that cover degrades, water erosion strips soil from fields and sends sediment into reservoirs and intakes. A site that depends on this service pays for erosion control or dredging. Resilience books that cost as a Business interruption loss, against revenue only.

What the map shows

• Today: Soil Retention Degradation. Water erosion at the site, compared with the erosion the cell would have under the natural cover of its WWF biome. 0 points is the natural erosion; 100 points is 11 t/ha/yr above it, the OECD severe-erosion class.
• Projected: Soil Retention Shock layers for SSP1, SSP2 and SSP3, at 2035, 2050 and 2080. Erosion moves with projected rainfall erosivity and the GloSEM land-use trend. SSP1 reads GloSEM RCP2.6, SSP2 reads RCP4.5, and SSP3 reads RCP8.5, since GloSEM has no RCP7.0 run.

This service has its own layers, so it does not go through the natural assets.

How the loss is computed

The degradation D, between 0 and 1, is read from the layer at the site. The dependency is the ENCORE rating of the site's activity, read as (rating − 1) / 4. The loss is D × min(dependency, k) × revenue, where k is the yearly cost of replacing the service, as a share of revenue. k exists for high- and low-input agriculture, managed forest, hydropower, mining and construction. Its values are provisional placeholders. Other site types keep D × dependency. See Nature risks and Shock layers.

Sources

• RUSLE2016 and EU C-factor (Panagos et al. 2015, 2020, JRC/ESDAC). ESDAC data licence (registration, no redistribution of the data).
• Global soil erodibility (Panagos et al. 2024, JRC/ESDAC). ESDAC data licence (registration, no redistribution of the data).
• ESA CCI Land Cover 2020 (C3S). Licence not confirmed.
• WWF Terrestrial Ecoregions (Olson et al. 2001). Licence not confirmed.
• GMTED2010 (USGS). Public domain.
• GloREDa and projected rainfall erosivity, 19 GCMs (JRC/ESDAC). ESDAC data licence (registration, no redistribution of the data).
• GloSEM land-use trend (Borrelli et al. 2020). ESDAC data licence (registration, no redistribution of the data).
• ENCORE 2024 (Global Canopy, UNEP FI, UNEP-WCMC): dependency ratings. CC BY-SA 4.0.

Limits

• Outside the EU, the world method overestimates Scandinavia by 2 to 3 and underestimates Central Europe. The tropics and deserts lie outside its calibration.
• Where natural erosion already reaches 11 t/ha/yr, the cell reads no data, never 0.
• 2080 is extrapolated past 2070: read it as a direction rather than a level.
• The natural reference keeps today's climate.