The previous units showed what the SEA sections on policy context, environmental baseline and environmental problems can contain and look like. The next few units discusses some of the factors that need to be considered when these sections are being compiled. This unit explains the concept of indicators, objectives and targets. Units 8-12 give more detail. Readers who want a more rapid overview of the SEA system should proceed directly to Unit 13.
Although it may be possible to fully describe the baseline environment for a project, this is simply not feasible for most SEAs. Instead, in SEA, subsets of the full baseline data are typically collected and described through indicators. An indicator is a "piece of information which is used to measure and track the status and progress of a complex system" (DETR, 1999). Indicators, as suggested by their name, indicate: they represent a topic or theme, but do not attempt to cover it comprehensively. Thus the choice of indicators is crucial.
|indicator||example of resulting data||comments on indicator|
|current level of NOx (air pollution) at site A based on monitoring
|| quantitative,objective, single time and location
|average of annual NOx levels at sites A-H
|| quantitative, objective, multiple times, multiple locations
|expert M's opinion about current level of NOx at site A
|| "probably low, since it is not near a road or other major NOx emitter"
|| qualitative, subjective, single time and location
|perceived safety of area X, 200 residents' opinions
|| 3 out of 10 (1 very unsafe, 10 very safe)
|| quantitative, subjective
|burglaries per 1000 people per year in area X
|| quantitative, objective
Indicators can be monitored and documented over time, to shown trends: whether the environmental baseline is getting better or worse. An example is:
|level of NOx at site A, annual average||6.4Âµg||5.5Âµg||5.0Âµg|
For most SEA indicators, it should be possible to identify a preferred direction of change: for instance, levels of NOx should be reduced, or air quality should be improved. In SEA, such a statement is typically called an SEA objective. SEA objectives can also be devised in the absence of indicators or data, to act as a list of environmental aspirations for the strategic actions. This is discussed further in Unit 12.
Objectives can be phrased more specifically, as a quantitative level that is expected to be achieved by a given date. In SEA, this is typically called a target. The achievement of targets can be monitored through the use of indicators. The table below gives examples of indicators, objectives and targets.
|Topic||Air Pollution||Basic Needs|
|Objective||To reduce NOx levels at sites A, B and C||To reduce homelessness|
|Target||To reduce NOx levels to 90% of 2005 levels by 2015 at sites A, B and C||To provide accommodation for all homeless households in area A by 2015|
|Indicator||NOx levels at monitoring stations A, B and C||Homeless households in area A|
The interactive animation below is adapted from the UK Government good practice guide on regional planning guidance. It demonstrates how indicators are the link between the strategic action and SEA objectives. Indicators also provide a link between the baseline environment, and impact prediction and mitigation.