Identification

Title

Historic GQA Headline Indicators of Water Courses - Biology

Abstract

This record is for Approval for Access product AfA161. The General Quality Assessment (GQA) Headline Indicator scheme or GQAHI (previously known as GQA) was the Environment Agency's 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 as a national picture. These assessments were made for Biological, Chemical and Nutrients and undertaken for discrete river stretches. 4978 river stretches are included in the biology assessment which represent approximately 22,773km. The Biology assessment gave an indicator of the overall 'health' of rivers. It describes water quality in terms of 83 groups of macroinvertebrates. Macroinvertebrates are small animals that can be seen with the naked eye. Some of these are pollution sensitive so their presence suggested better water quality. The assessment was made by carrying out a bi-yearly (Spring/Autumn) three minute active sampling with a pond net and a one-minute visual search for animals living on the surface or attached to rocks or vegetation. The number of taxa present were recorded and the Biological Monitoring Working Party score calculated. These values were then compared with values expected at a site in a similar, but totally unpolluted river. The mathematical model RIVPACS (the River Invertebrate Prediction and Classification System) was used to predict fauna in the absence of pollution. A category was assigned to the river stretch where the monitoring point was located: A - Very Good: Biology similar to that expected for an average and unpolluted river of this size, type and location. High diversity of groups, usually with several species in each. Rare to find dominance of any one group. B - Good: Biology falls a little short of that expected for an unpolluted river. Small reduction in the number of groups that are sensitive to pollution. Moderate increase in the number of individuals in the groups that tolerate pollution C - Fairly Good: Biology worse than expected for an unpolluted river. Many sensitive groups absent or number of individuals reduced. Marked rise in numbers of individuals in groups that tolerate pollution. D - Fair: Sensitive groups scarce and contains only small numbers of individuals. A range of pollution tolerant groups present, some with high numbers of individuals. E – Poor: Biology restricted to pollution tolerant species with some groups dominant in terms of the numbers of individuals. Sensitive groups rare or absent. F – Bad: Biology limited to a small number of very tolerant groups (such as worms, midge larvae and leeches), present in very high numbers. In the worst case, there may be no life present. Sample points represent one or many stretches; there are approximately 3270 biology sample points. Issues to Note: Additional attributes are added annually (2008 attributes are represented) with 2009 being the last year of the scheme. In 2007 the England GQA river network was reduced to the GQAHI river network. The data described have been amended to be consistent for all years. Attribution statement: © Environment Agency copyright and/or database right 2015. All rights reserved.

Resource type

dataset

Resource locator

https://environment.data.gov.uk/datafiles/aff0014588434d18b5e59623116b4b03

protocol: WWW:LINK-1.0-http--link

name: Data_download_link

description: Data download link

https://support.environment.data.gov.uk/hc/en-gb

protocol: http:

name: DSP_CUSTOMER_FORUM

description: DEFRA Data Services Platform Customer Forum

Unique resource identifier

code

63e365b0-d465-11e4-bcaa-f0def148f590

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

http://www.opengis.net/def/crs/EPSG/0/27700

Classification of spatial data and services

Topic category

environment

inlandWaters

Keywords

Keyword set

keyword value

water quality

monitoring technique

monitoring data

OpenData

originating controlled vocabulary

title

GEMET Thesaurus version 2.1

reference date

date type

publication

effective date

2008-06-13

Geographic location

West bounding longitude

-6.236

East bounding longitude

2.072

North bounding latitude

55.816

South bounding latitude

49.943

Extent

Extent group

authority code

code identifying the extent

http://data.ordnancesurvey.co.uk/doc/country/england

Extent group

authority code

code identifying the extent

http://data.ordnancesurvey.co.uk/doc/country/wales

Temporal reference

Temporal extent

Begin position

2006-04-01

End position

2010-04-01

Dataset reference date

date type

creation

effective date

2010-01-01

Frequency of update

notPlanned

Quality and validity

Lineage

The Biology GQAHI described quality in terms of ecology specifically macro-invertebrates. At each sample location two macro-invertebrate samples were collected once every three years and each assessment was based on a three year period. Data is represented as river stretches and stored in an zipped access database in two tables on the O drive (Environment Agency's shared drive).

Conformity

Data format

name of format

Proprietary format | ESRI, Intergraph, MS Access (MDB)

version of format

Unknown

Constraints related to access and use

Constraint set

Use constraints

Open Government Licence

Constraint set

Limitations on public access

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

Responsible organisations

Responsible party

organisation name

Environment Agency

email address

DSPcustomerforum@environment-agency.gov.uk

web address

https://support.environment.data.gov.uk/hc/en-gb

description: Defra Data Services Forum

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

organisation name

Environment Agency

email address

metadata@environment-agency.gov.uk

responsible party role

pointOfContact

Metadata date

2020-09-29

Metadata language

eng