Hydrionis Derived Climatology Dataset
Reference normals and decadal means computed by Hydrionis from the long observational records it holds, with the full input chain recorded for every value.
Methodology
Computed through the Hydrionis derivation engine. Reference normals are arithmetic means over the complete WMO 1991–2020 period, produced only where all thirty years are held. Decadal means are produced only where at least eight of a decade’s ten years are held, and for compositional metrics such as the withdrawal sector shares, only over the years every member of the composition holds — averaging shares independently produces components that no longer sum to their total. Every value carries its method, method version, formula, input observation identifiers, input source identifiers and the limitations of the method that produced it.
What this dataset cannot tell you
Coverage
| Subjects | Every subject for which Hydrionis holds a sufficiently complete record — 5,158 held |
|---|---|
| Period | 1840–2010 |
| Units | %, Mm³, km³/yr, m, mg/l, mg/l as N, mg/l as P, mm, m³/person/yr, m³/s, pH, °C |
| Update cadence | Irregularly, when the publisher releases |
| Identifier | hydrionis-derived-climatology v1.0.0 |
Rights and access
Licence position
Open with attribution. Derivative use true; redistribution true; commercial reuse true.
Attribution required:
- Data from Eurostat, used under European Commission reuse policy (Decision 2011/833/EU).
- Source: Hub’Eau / Système d’information sur l’eau, under Licence Ouverte (Etalab).
- Contains public sector information licensed under the Open Government Licence v3.0.
- Data from World Bank, used under CC BY 4.0.
- HadUK-Grid is available under the Open Government Licence via the CEDA archive, which requires free registration. Other Met Office products, including forecast and commercial services, are separately licensed and are not open.
- Applies to material authored by US federal agencies. Third-party material carried within a federal product may be separately protected.
Permitted uses
- Public display
- Derived analysis
- API delivery
- Bulk download
- Commercial use
Available to: Public, Developer, Research, Professional, Enterprise. These follow from the rights of the contributing publishers, not from a Hydrionis pricing decision — no access tier can widen what a publisher withheld.
Contributing sources
- Eurostat — Water statistics
- Office français de la biodiversité / SCHAPI — Hydrométrie — French river flow and stage
- Bureau de recherches géologiques et minières — Piézométrie — French groundwater levels
- Environment Agency — Hydrology Data Explorer API
- Environment Agency — Water Quality Archive (WIMS)
- Met Office — HadUK-Grid gridded climate observations
- Scottish Environment Protection Agency — SEPA water environment data
- United States Geological Survey — National Water Information System
- World Bank — World Development Indicators
Suggested citation
Hydrionis (2026), Hydrionis Derived Climatology Dataset, version 1.0.0. Retrieved from https://hydrionis.com/data/datasets/hydrionis-derived-climatology/
Cite the version. Hydrionis datasets change as publishers release and as methods are revised, and a citation without a version cannot be checked later.
Changelog
Version 1.0.0 — 2026-08-24
First release of the governed derivation layer.
Additions
- Reference normals and decadal means with full input provenance.
Getting the data
This dataset is not available as a bulk download:
Machine-readable metadata for this dataset is at /api/v1/datasets/hydrionis-derived-climatology.json. For bulk extracts, higher-volume access or commercial licensing, see data enquiries.