The impacts of a strategic action are the difference between the future environment without and with the strategic action. This is shown in the figure below. The current environment, and the future environment without the strategic action together are called the environmental baseline.
Knowledge about the environmental baseline is important in SEA because it helps to:
- identify existing environmental problems that the strategic action should avoid making worse or try to improve
- act as a 'business as usual' (no action) alternative to the proposed strategic action and alternatives
- set a basis for impact predictions
- provide a starting point for impact monitoring and auditing.
What are components of the environmental baseline?
Typically the environmental baseline would describe the status of the following environmental receptors (n.b. those topics marked with * must be addressed in SEAs prepared in response to the European SEA Directive and/or UNECE SEA Protocol):
- water - quantity and quality*
- soil and geology*
- climatic factors*
- flora and fauna (biodiversity)* - sometimes split into marine, freshwater and/or terrestrial; sometimes split into separate habitats and species
- landscape* (including light pollution and tranquil areas)
- noise - this is generally more applicable at the local than the regional/national level
Often the SEA will describe more social baseline aspects as well:
- cultural resources* - historic buildings, landscapes, architecture
- population* and human health*
- material assets* - infrastructure, housing quality and quantity etc.
Often the baseline describes 'natural resources' or sectors, for instance:
- sewerage and/or waste management
- land use
- mineral deposits
- materials use in construction and operation
And where SEA is broadened out to cover the full gamut of social and economic issues, the baseline will also cover issues such as:
- poverty, deprivation, equity
- economic growth
The level of detail with which the baseline environment can be described will vary with the type of strategic action and the availability of appropriate data. Descriptions for a local-level plan or programme-level SEA are likely to be more detailed than those for a national-level plan or policy SEA.
Data sources and availability
Data about strategic-level baseline conditions are normally not elegantly compiled in a comprehensive and easily-accessible database, ready for use in SEA. Where data are needed for several administrative areas, they will often be frustratingly incompatible with each other, based on different assumptions, and stored in different ways. Good luck! Starting points for gathering information about the environmental baseline are:
- 'state of the environment' reports:
- United Nations Environment Programme and OECD both have links to dozens of countries' SoE reports, and some of these include information for the regional and local level; and
- European Environment Agency: reports on Europe-wide environmental issues and sectors as well as Member States' state of the environment reports;
- the context-setting section of current sectoral or regional plans;
- monitoring programmes, GIS data, aerial photos;
- maps, both current and historical (which may show, for instance, likely past sources of contamination);
- the computers, desks, files, piles of paper, brains etc. of relevant officials; and
- less formally, from talking to other experts and/or the public.
It is possible to carry out very useful SEAs with only minimal 'formal' baseline information if people who know about conditions in the area are involved in the plan-making and SEA process. This is the approach taken in abbreviated versions of SEA such as 'environmental overview' (Brown, 2000).