Historic General Quality Assessment (GQA) Headline Indicators of Water Courses - Nutrients
The General Quality Assessment (GQA) Headline Indicator scheme or GQAHI (previously known as GQA) was the national indicator for water quality in rivers and canals. It was designed to provide an accurate and consistent assessment of the state of water quality and how it changes over time. These assessments were made for Biological, Chemical and Nutrients and undertaken for discrete river stretches. This datasets relates to the nutrient assessments. In Wales we maintained the full GQA network until 2010 based on 800 sampling sites which provided information for approximately 4700km. The GQAHI/GQA scheme was designed to provide an accurate and consistent assessment of the state of water quality and how it changes over time. The Nutrients GQA described quality in terms of two nutrients: nitrates (mg NO3 /l) and phosphates (mg P/l) and graded from 1 to 6.
- Identification
- Extent
- Distribution
- Quality
- Keywords
- Spatial Reference System
- Content
- Constraints
- Maintenance
- Metadata
Identification
- Identifier
- NRW_DS116326
- Alternative Title
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- AfA163 Historic GQA Headline Indicators of Water Courses – Nutrients
- Metadata Language
- English
- Lineage
-
The Nutrients GQA described quality in terms of two nutrients: nitrates (mg NO3 /l) and phosphates (mg P/l) and graded from 1 to 6. Grades were allocated for both phosphate and nitrate; they were not combined into a single nutrients grade. There were no set 'good' or 'bad' concentrations for nutrients in rivers in the way that we describe chemical and biological quality. Rivers in different parts of the country have naturally different concentrations of nutrients. ‘Very low’ nutrient concentrations, for example, are not necessarily good or bad; the classifications merely stated that concentrations in this river were very low relative to other rivers. Classification for phosphate Grade limit (mgP/l) Average Description: 0.02 to 0.06 Low >0.06 to 0.1 Moderate >0.1 to 0.2 High >0.2 to 1.0 Very high >1.0 Excessively high Classification for nitrate Grade limit (mg NO3/l) Average Description: 5 to 10 Low >10 to 20 Moderately low >20 to30 Moderate >30 to 40 High >40 Very high. 2009 was the final year of the scheme.
- Dataset Reference Date (Publication)
- 2016-07-01
Extent
Extent
- Geographic Extent
- Wales (WLS)
))
Distribution
Distribution
- Format Type and Description
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Documents
()
- Specification
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Excel
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Documents
()
- Resource Locator
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Download data
World Wide Web page
Quality
Data quality
- Quality Scope
- Dataset
- Lineage
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The Nutrients GQA described quality in terms of two nutrients: nitrates (mg NO3 /l) and phosphates (mg P/l) and graded from 1 to 6. Grades were allocated for both phosphate and nitrate; they were not combined into a single nutrients grade. There were no set 'good' or 'bad' concentrations for nutrients in rivers in the way that we describe chemical and biological quality. Rivers in different parts of the country have naturally different concentrations of nutrients. ‘Very low’ nutrient concentrations, for example, are not necessarily good or bad; the classifications merely stated that concentrations in this river were very low relative to other rivers. Classification for phosphate Grade limit (mgP/l) Average Description: 0.02 to 0.06 Low >0.06 to 0.1 Moderate >0.1 to 0.2 High >0.2 to 1.0 Very high >1.0 Excessively high Classification for nitrate Grade limit (mg NO3/l) Average Description: 5 to 10 Low >10 to 20 Moderately low >20 to30 Moderate >30 to 40 High >40 Very high. 2009 was the final year of the scheme.
Keywords
Keywords
Keywords
Keywords
Spatial Reference System
- Code
- NONE
Content
Content Information
NRW Profile
Custom Elements
Constraints
Constraints
Limitations on Public Access and Use
- Restriction type
- Other restrictions
Access Constraints Directive
- Limitations
- no limitations
Access Constraints Text
- Other constraints
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There are no access restrictions on this data. NRW may release, publish or disseminate it freely.
Use Constraints
- Use constraints type
- Other restrictions
- Other constraints
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© CNC/NRW Data may be re-used under the terms of the Open Government Licence providing it is done so, acknowledging both the source and NRW's copyright. It is the recipient's responsibility to ensure the data is fit for the intended purpose. Attribution statement: Contains Natural Resources Wales information © Natural Resources Wales and Database Right. All rights Reserved.
Metadata
Metadata
- File Identifier
- 4f4c4942-4343-5764-6473-313136333236 XML
- Metadata Language
- English
- Parent Identifier
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Historic General Quality Assessment (GQA) Headline Indicators of Water Courses
NRW_DS118585
- Resource type
- Dataset
- Metadata Date
- 2024-05-31T09:14:21.511Z
- Metadata Standard Name
- NRW
- Metadata Standard Version
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1.0