National river classification schemes

Indicator Fact Sheet (Deprecated)
Prod-ID: IND-255-en
Also known as: WEC 04e
expired
Topics: ,
This content has been archived on 07 May 2015, reason: No more updates will be done

Assessment made on  13 Oct 2003

Generic metadata

Classification

Water Water (Primary theme)

DPSIR: Impact

Identification

Indicator codes
  • WEC 04e
Contents
 

Policy issue:  Is good surface water ecological status being achieved and the deterioration of aquatic ecosystems and habitats prevented?

Figures

Key assessment

River classification schemes are often designed to give an indication of the extent of pollution. There are many different types of schemes. Some are based solely on chemical and general physico-chemical parameters (for example, pH, dissolved oxygen, ammonium and biochemical oxygen demand), some on biological indices (usually based on macro-invertebrates) and some on a combination. Although all the countries have different schemes they give a general indication of river quality, particularly whether according to a country's scheme there has been an improvement or not.

None of the classification schemes meet the requirements of the water framework directive and hence there is at present no information enabling a direct assessment of the situation in relation to the objectives of the directive. Different types of schemes cannot be quantitatively compared hence Figure 2.2 is divided into three types (biological, physico-chemical, combined). Some countries have more than one national classification scheme and so results for each scheme are shown separately, for example England and Wales has a physico-chemical scheme and a biological scheme. This separation into types of scheme also illustrates that whilst one scheme may show an improvement in quality, another may show deterioration for example, the UK (Northern Ireland) chemical scheme showed an improvement whilst the biological scheme showed a deterioration. This was because the biological scheme reflects a degradation in habitat quality as well as changes in water quality.

The majority of river classification schemes show an improvement in quality reflecting the effects of reduced pollution by human activities on the aquatic environment. Figure 2.3 shows the percentage of rivers classified as less than good. There are large differences with countries such as the Czech Republic, Latvia and Poland having relatively large, and UK relatively small percentages less than good quality. However, there is a wide variation in the length of national rivers included in classification schemes. The average length of river classified was only about 30 % of the total length of river in the country. This means that the real picture can be very different from the one presented here.

Permalinks

Permalink to this version
c5e29e73773be398e97179bcd731aea0
Permalink to latest version
IND-255-en
European Environment Agency (EEA)
Kongens Nytorv 6
1050 Copenhagen K
Denmark
Phone: +45 3336 7100