CLASSIFICATION FOR SCOTLAND
The EU Water Framework Directive (WFD), through its translation into
Scots Law by the Water Environment and Water Services (Scotland) Act
2003 (WEWS) introduces a series of new wetland related duties for SEPA,
and it has been recognised that an inventory of water body dependent
wetlands will be an important first step in meeting these requirements.
The overall objective of the project was to produce an inventory of
water body dependent wetlands, based on readily available information,
and to detail priorities for future research. Three specific objectives
were identified from the outset of the project:
Subsequent steps will enhance the level of detail contained within the
inventory. The aim of this project was to deliver the initial phases of
the inventory, and to develop a prioritised workplan to support its
completion. However, due to limitations in national datasets, it has
not been possible to deliver an inventory of Scottish wetlands. The
project has produced a hydrogeomorphic classification of potential
wetland areas within the Scottish landscape. Using this approach it is
possible to construct an inventory of potential wetland sites and to
assess their likely surface and groundwater dependence.
- To deliver an inventory of Scottish wetlands that are
directly dependent on surface water bodies and groundwater bodies;
- To describe the pressures affecting wetlands listed on the
- To develop a prioritised plan for future wetland
characterisation work covering aspects of the wetland resource not
included in the wetland inventory to be delivered through this project.
A GIS-based wetland hydrogeomorphic classification has been created for
Scottish wetlands. The classification provides information on both
designated and non-designated sites. Through a GIS it is possible to
define the likelihood of dependency of any wetland area on surface and
groundwater bodies by assessing likely water sources. Through an
interpretation of the surface and groundwater sources it is possible to
identify potential pressures on wetlands.
The information generated within the GIS has been validated against
digitized National Vegetation Classification (NVC) communities
available for 176 SSSIs. The validation process recognizes that NVC
communities are not perfect surrogates for defining wetlands
and their water dependence. Correlations (both Spearman’s and
Chi-square) yield highly significant results. However, there are subtle
relationships within the output data which need to be understood prior
to drawing immediate conclusions. A high degree (>80%) of
agreement has been achieved for predicting high groundwater dependency.
A much lower degree (~50%) of agreement has been achieved for
predicting low groundwater dependency. Hydrogeomorphic units derived to
describe extensive peatland areas yield the best results for predicting
the potential location of wetlands in the Scottish landscape. A variety
of different hydrogeomorphic units demonstrate a strong association
with wetland NVC communities. Mapping of these hydrogeomorphic units
within the GIS generates an initial inventory of areas of high
potential to support wetlands and provides information on the ground
and surface dependent water bodies.
A user’s guide is provided to assist users in investigating
the GIS and deriving information on water body dependency and potential
The hydrogeomorphic classification is not a finished product and should
be continually updated and reviewed to improve the ability to generate
an accurate inventory of Scottish wetlands. A prioritized workplan is
presented to inform future research needs.
wetlands, inventory, surface water dependency, groundwater dependency,
pressures, Water Framework Directive, GIS, hydrogeomorphic
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format on CDRom at £20.00 + VAT or hard copy at
£25.00, less 20% to FWR members.
The report is available for download from the SNIFFER Website.