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  3. WFD Cycle 2 river hydrology classification

WFD Cycle 2 river hydrology classification

Summary

This dataset is a subset of "WFD Classification Status Cycle 2" and contains classification data for hydrological regime. A river can only hold a healthy biological population if there is sufficient water and natural structures to support biological processes. Rivers with sufficient flows can also support human activities such as farming, drinking water supply and industrial processes. The hydrology assessment tool uses data on freshwater flows, physical modification and water abstraction to assess the health of a water body. The tool works by assessing a water body’s compliance category (freshwater inputs less abstraction amounts) against a score for flow compliance. A water body cannot score high status if it is considered to be ‘heavily modified’ which refers to a river being modified from its natural state for human use. If a water body considered heavily modified scored high in the compliance and flow tests it would be automatically downgraded to ‘Supports Good’ status. Flow, abstraction and physical structure data are used in combination to produce scores known as Ecological Quality Ratios (EQR). EQRs are used to produce a Hydrology classification (High, Supports Good, Good, Moderate, Poor, Bad) of the water body for Water Framework Directive (WFD) purposes.

Categories

Use limitation statement

There are no public access constraints to this data. Use of this data is subject to the licence identified.

Attribution statement

© Environment Agency copyright and/or database right 2015. All rights reserved.

Technical information

Update frequency

annually

Lineage

The Water Framework Directive classification system is risk based and focuses on where there is likely to be a problem. It uses a principle known as "one out, all out", which means the poorest individual results drive the overall classification for a water body. It reports on over 30 quality elements, grouped into ecological status and chemical status. Ecological status includes physico-chem (e.g. nutrients, pH, dissolved oxygen, ammonia) , biological elements (e.g. phytoplankton, macroalgae, fish, invertebrates) , specific pollutants (e.g. metals and compounds, organic compounds) , hydromorphology (e.g. depth, width, flow, structure). Chemical status is assessed using priority substances, priority hazardous substances and other pollutants that present a significant risk to the water environment.

Spatial information

Geographic extent

  • Latitude from: 49.943 to 55.816
  • Longitude from: -6.236 to 2.072
Metadata information

Language

English

Metadata identifier

4843f31c-917d-4a16-8b13-93e1e1a78c49


Published by

Environment Agency

Contact publisher

Defra Data Services Forum

Dataset reference dates

Creation date

09 December 2015

Revision date

N/A

Publication date

N/A

Period

  • From: 02 December 2015

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Data and Supporting Information
Data services and download by area of interestLinkAction
Full downloads and supporting documentationFormatAction
WFD_SW_Classification_Status_and_Objectives_Cycle2_v3.xlsxXLSXDownload