1 Scope
This European Standard is applicable to lakes, which are water bodies occupying one
or more basins with surface areas greater than 1 ha (0,01 km2) and maximum depths (at mean water level) greater than 1 m. All types of permanent
lakes, including natural, modified and artificial, freshwater and brackish, except
for those systems which regularly connect to the sea, are included in this European
Standard, though canals are excluded.
Based on these criteria, it can be estimated that there are at least 500 000 natural
lakes across Europe, most of which are located in the glaciated landscapes in northern
and western provinces and in Scandinavia. Lakeland districts also occur locally in
areas such as the Danubian plain and around the Alps. Elsewhere, naturally occurring
lakes are relatively sparse and in such areas reservoirs or pits are more common.
This European Standard is designed to:
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a) support environmental and conservation agencies in meeting the monitoring requirements
of the WFD (Article 8, Annex II and Annex V);
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b) generate data sets appropriate for monitoring and reporting of Natura 2000 sites designated under the Habitats Directive and the Birds Directive;
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c) provide information supporting other environmental reporting requirements (e.g. in
relation to biodiversity or environmental impact assessment);
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d) support lake management and restoration initiatives.
This European Standard:
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e) defines the key term of ‘hydromorphology’ and other terms relating to the physical characteristics of lakes and their hydrological
regimes;
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f) details essential features and processes of lakes that should be characterised as
part of a hydromorphological survey and for determining the hydromorphological condition
of a lake;
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g) identifies and defines the key pressures affecting European lakes;
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h) provides guidance on strategies for collecting hydromorphological data depending on
resources available and the anticipated use of the assessment; a hierarchy of approaches
is recognised from the ‘overview method’ utilising existing databases, maps and remote
sensing data through to recognised field-based survey techniques such as Lake Habitat
Survey (LHS);
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i) offers guidance on data presentation;
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j) establishes guidance on data quality assurance issues.
This European Standard does not deal with biological assessments in lakes such as
the presence or absence of individual species or community composition, nor does it
attempt to link specific hydromorphological features with their associated biological
communities or to create a classification based on such links. However, it is relevant
where plants or other organisms form significant structural elements of the habitat
(e.g. a gradation from riparian to littoral vegetation).
With respect to the WFD, the hydromorphological condition of a lake only contributes
to its status classification at high ecological status (HES). Hydromorphological conditions are not defined for good and moderate status
but shall be sufficient to support the biological elements.