Water Purification Degradation
This layer maps how far 2015 river nitrogen degraded the water-purification service, the present-day level of the Water purification row in Resilience.
Source: Chaplin-Kramer et al. 2019 (InVEST NDR), HydroSHEDS, TerraClimate, Naïades Year: 2015 Category: Scenario Coverage: Where the routed river nitrogen exists. No value north of about 60° N or where runoff is under 10 mm/yr. Format: Raster grid (COG), nitrogen routed on the HydroSHEDS 30″ network Used in risk analysis: Yes. It is the present-day level of the Water purification row in Resilience, and it gates the Water purification row of Enabling services on Sites & territories.
What it shows
This layer shows how much river nitrogen degraded the water-purification service in 2015, in points. It covers the nitrogen part only. Contamination by metals, pesticides and PFAS is its own layer, the Water Purification Contamination Index.
Resilience reads it as the level of the Loss of water purification row. The Water Purification Loss layers carry the projected change.
How it is built
D = clip( (C − 0.3) / (11.3 − 0.3), 0, 1 ) × 100
- C is the routed 2015 river nitrogen concentration, in mg N/L. The nitrogen export of Chaplin-Kramer et al. (2019) is routed down the HydroSHEDS 30″ network, then divided by the routed TerraClimate runoff. The result is calibrated by dividing by 2.67, fitted on French river nitrate (Naïades, 2014-2016).
- 0.3 mg N/L is pre-industrial river nitrogen: 0 points.
- 11.3 mg N/L is the limit of the EU Nitrates Directive: 100 points.
The layer is a state, and it is deliberately not tagged as a shock layer. Tagging it would make it compete with the Water Purification Loss layers for the Water purification row.
How to read it
0 points is pre-industrial river nitrogen. 100 points is the Nitrates Directive limit or above. A cell has no value where the routed concentration is missing: north of about 60° N, and where runoff is under 10 mm/yr. The Water Purification Data Coverage layer shows those gaps.
The calibration is fitted on France. The Loss of water purification page states that it is applied worldwide without a check elsewhere.
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) |
|---|---|---|---|
| Enabling services | Water purification | Value above 10.9 points: "Eutrophic river nitrogen (> 1.5 mg N/L, Dodds et al. 1998)" | "Water purification" ≥ 4 |
Source
Chaplin-Kramer et al. (2019), Science 366:255, InVEST NDR outputs (Zenodo 21249617), licensed CC BY 4.0. HydroSHEDS (Lehner & Grill 2013), used under the HydroSHEDS v1 licence (WWF); its required statement is on the Loss of water purification page. TerraClimate (Abatzoglou et al. 2018), CC0 1.0. Naïades river quality data (OFB / Agences de l'eau, via Hub'Eau), Licence Ouverte Etalab 2.0. Ceiling after the EU Nitrates Directive.
Legend
Symbolised field: Water purification degradation (points)
| Value | Colour |
|---|---|
| 0 | #1a9850 |
| 10 | #a6d96a |
| 25 | #ffffbf |
| 50 | #f46d43 |
| 100 | #800026 |
Generated from darwin/layers/layer-water-purification-degradation-2015.toml and risk_indicator_pairs.toml (develop).