انتخاب شاخص زیست محیطی برای استفاده در ارزیابی زیست محیطی استراتژیک

The primary aim of carrying out Strategic Environmental Assessment (SEA) is to provide for a high level of environmental protection and to integrate environmental considerations into the planning process. The SEA Directive (2001/42/EC) recommends monitoring to determine the environmental impact of the implementation of plans and programmes. Environmental indicators are a useful tool by which this impact may be measured. However, careful consideration must be given to developing a set of indicators in order to isolate, plan or programme specific impacts. Here, we demonstrate the effectiveness of a workshop-based approach to develop appropriate criteria for selecting environmental indicator for use in SEA. A multi-disciplinary team was used in the approach which consisted of representatives from each of four environmental fields i.e. biodiversity, water, air and climatic factors, together with SEA experts, planning experts, academics and consultants. The team reviewed various sets of criteria, already in existence, for environmental indicator development but not specifically for SEA indicators. The results of this review together with original criteria were applied to the final list agreed upon. Some of the criteria recommended includes, relevance to plan, ability to prioritise, and ability to identify conflict with other plan or SEA objectives.

The use of environmental indicators at the national, regional, local and field level has become a common assessment tool (Bockstaller and Girardin, 2003). There is a growing need to establish appropriate environmental indicators to allow decision makers to make informed judgements regarding policies, programs, plans and projects (Cloquell-Ballester et al., 2006). The European Environment Agency's (2005) definition of an indicator is ‘a measure, generally quantitative, that can be used to illustrate and communicate complex phenomena simply, including trends and progress over time. An indicator provides a clue to a matter of larger significance or makes perceptible a trend or phenomenon that is not immediately detectable. An indicator is a sign or symptom that makes something known with a reasonable degree of certainty and reveals, gives evidence, and its significance extends beyond what is actually measured to a larger phenomenon of interest.’ In other words, indicators are measurable aspects of a project/environment/society that can be used to monitor its progress or direction (www.stats.govt.nz/products-and-services/user-guides/indicator-guidelines). The US Environmental Protection Agency together with the US Geological Survey define an environmental indicator to be ‘a measurable feature or features that provide managerial and scientifically useful evidence of environmental and ecosystem quality or reliable evidence of trends in quality’. Consequently, environmental indicators should be measurable, scientifically valid and capable of providing information for management decision-making. In Strategic Environmental Assessment (SEA) environmental indicators may be used to demonstrate the changes in environmental quality resulting from the implementation of plans and programmes. Indicators must provide appropriate information to enable the objectives and targets, of the SEA, to be addressed. In addition, Cloquell-Ballester et al. (2006) suggest that indicators should be validated and accepted beforehand by participants and stakeholders of any impact assessment process. Therefore, it is useful to establish a set of criteria that can be used to select environmental indicators for use in SEA. A key function of an indicator is to reduce the volume and complexity of information which is required by decision makers. For example, air or water quality indices are generally used as a measure of pollution; they usually imply that the better the air or water quality the less pollution. However, behind these indices are complex data on concentrations of chemicals or particulate matter in the receiving body. In order to make decisions, the decision maker needs to know if the air quality is a threat to human health or agricultural crops or if water is fit to bathe in, drinkable or can sustain a sensitive fish community. It is not necessary for the decision maker to know the detail behind these indices but it is the job of the indicator to relay this complex information in an accurate and understandable manner in order for informed decisions to be taken. Many sets of indicators exist that have been developed to address specific environmental issues. Some of these include the OECD core set of environmental indicators (OECD, 2004) which consists of about 50 indicators covering issues that reflect the main environmental concerns in OECD countries. These indicators, and many others, are classified using the Pressure-State-Response (PSR) model composed of indicators of environmental pressures (direct and indirect), environmental condition (state) and society's response. In addition, the OECD provide a list of key environmental indicators which is a reduced set of their core indicators that serve communication purposes to inform the general public and provide key signals to policy-makers (OECD, 2004). Furthermore, the European Environment Agency (EEA) have also developed a core set of environmental indicators, 37 in total, which have been developed to provide a manageable and stable basis for indicator based reporting by the EEA, to prioritise improvements in the quality and geographical coverage of data flows and to streamline EEA contributions to other European and global indicator initiatives, such as, EU structural indicators and OECD environmental indicators (EEA, 2005). There is of course substantial overlap between these sets of indicators and each set has slightly different criteria associated with it or it may cover a different geographical area such as worldwide (OECD) or European (EEA), nevertheless all sets are deemed necessary. As described above, of the similarities between the OECD and the EEA core sets of indicators, it is rarely possible to take one set of indicators and use it for another purpose. The reason for this is in the slight differences in the criteria used to establish the lists, which may point to subtle differences in the function of the indicator set. The OECD and EEA indicators could be used in SEA if the assessment was to be carried out on an OECD-wide or European scale. However, to date most are carried out at a more local level and therefore these sets of indicators are inapplicable. However, they do provide ideas of what type of environmental indicators may be available and where the data may be obtained. Table 1 presents examples of sets of criteria used to develop lists of indicators for (i) the EEA core set of environmental indicators, (ii) climate change indicators for Ireland, (iii) biodiversity and (iv) environmental assessment. It is clear that there are many similarities between these sets for example all include ‘scientifically valid’, ‘show trends’ and ‘understandable’ as key criteria. Furthermore, Bockstaller and Girardin (2003) suggest that in order for an environmental indicator to be considered valid it should be scientifically designed, provide relevant information and be useful to the end user. Donnelly et al. (2006a) reviewed several sets of indicators, available in Ireland, which have been used to determine the environmental impact of the transport sector, the impact of climate change on the environment and key environmental indicators used for reporting the state of the environment. The authors concluded that whereas these documents provided a valuable source of indicators they did not cover all sectors or all environmental receptors required under the SEA Directive, principally because the criteria did not fit SEA purposes. Therefore, it may not always be feasible and straightforward to simply transfer currently available processed data to SEA. This provides evidence for the need to develop environmental indicators specifically for the SEA process which should be accompanied by an associated set of criteria to ensure the indicators are fit for the purpose for which they are intended. The environmental indicators developed should be accompanied by a rigorous validation process such as, the 3S validation methodology, proposed by Cloquell-Ballester et al. (2006). In this method, 3 forms of validation are carried out i.e. self-validation, scientific validation and social validation. The indicators that were ultimately chosen in Donnelly et al. (2006a) were validated by the workshop team i.e. self validation, to ensure appropriateness to the issues in question. Scientific validation was ensured through adoption of previously used indicators and expert judgement. Finally, social validation was ensured by the participation of the many stakeholders which ensured the information being relayed was understandable. Because of the multifunctional nature of environmental indicators their development and selection has become a relatively complex process (Kurtz et al., 2001). They are expected to reflect a variety of environmental issues, tract or predict change, identify stressors or stressed systems and influence management decisions. This paper is intended to help select successful environmental indicators for use in SEA. The aims of this work are to (i) review criteria for environmental indicator selection already in existence and to determine their transferability to the SEA process, (ii) provide a set of criteria for environmental indicator selection specifically for the SEA process and finally, (iii) present a methodology for evaluating the chosen indicators against the criteria. The result will help optimise the number of environmental indicators required in SEA and focus the baseline data gathering process and the subsequent monitoring of the environment. A workshop-based approach to develop and evaluate the criteria is described.

There remains little published material on the successful use of environmental indicators in SEA which partly reflects the challenges surrounding identifying suitable indicators and the lack of long term established SEA monitoring programmes to date. Therefore, much of the work on environmental indicators, for SEA, remains in the theoretical stage. The major output from this workshop was the final list of criteria arrived at for selecting environmental indicators for use in the SEA process. This is an important development in the whole area of environmental indicators as they are crucial for the monitoring stage of SEA, an area which is only currently evolving but an area of great importance as it will ultimately demonstrate the impact of the proposed plan on the environment. The need for a list of criteria arose following the development of a methodology (Donnelly et al., 2006b) designed to help SEA practitioners decide upon a set of environmental indicators for a proposed plan. The next step was to refine this potential list of indicators to a more focused, practical and useable set through the application of a set of selection criteria. However, it is the end user who will ultimately decide if the environmental indicator is acceptable helped by the criteria and based on the objectives of the SEA (Kurtz et al., 2001). The multidisciplinary nature of the participants in the workshop ensured as many stakeholders as possible were involved in the criteria development process allowing a broad base from which expertise could be drawn and differing viewpoints to be incorporated. It also ensured validation of the indicators by consensus of experts and end users which is a minimum requirement recommended for indicator validation (Bockstaller and Girardin, 2003). The value of having participants with a planning background and others with an environmental background on the same team was highlighted. It was generally felt that this was desirable in most aspects of SEA given the fact that the SEA and planning processes should be carried out in tandem. In addition, where difference of opinions arose consensus was reached quickly. Having examined various sets of criteria used to develop environmental indicators for different end uses it was considered that unless the indicators meet these criteria they would be unlikely to fulfil their prime functions of measuring the impact on the environment. The criteria chosen should help the user to decide whether new indicators need to be added to the list or existing ones deleted (EEA, 2005). However, Noss (1990) stated, in relation to biodiversity indicators, that no single indicator will possess all of the desirable criteria therefore a set of complementary indictors is required. This is true for all sets of indicators and in order to reduce the number of potential indicators to a more useable list and thus ensure that the most pertinent environmental issues for SEA are properly addressed, it is important to set criteria before a final list of indicators is agreed upon. In general, it was considered that all the criteria established were necessary but there was some confusion over the meaning of some of the wording initially used, such as ‘flexible’, ‘covers a range of issues’ and ‘limits conflict’ so clearer definitions were established. In light of this, ‘flexible’ was changed to ‘adaptable’, ‘covers a range of issues’ was changed to ‘covers a range of environmental receptors’ and ‘limits conflict’ was changed to ‘identify potential conflict’. Cumulative or combination effects need to be examined in the criteria. This could also help establish possible links between a particular plan and other plans and programmes with potential impacts — negative or positive. Evaluating a set of indicators against the chosen criteria proved useful to (i) ensure all selection criteria were addressed by at least some of the indicators, (ii) identify indicators that could not be supported by available data and (iii) highlight indicators that were irrelevant. In practice, this will result in an optimum set of environmental indicators for a particular SEA which will lead to an efficient monitoring programme, reduced costs and maximised use of resources. 4.1. Conclusions (i) It was not possible to use a set of criteria already in existence to select environmental indicators for SEA purposes. (ii) The multidisciplinary approach adopted facilitated the views of as many stakeholders as possible to contribute to the development of the criteria. This in turn ensured less bias in the decision making process. (iii) It is important to set criteria before a final list of indicators is agreed upon to ensure the most pertinent environmental issues for SEA are properly addressed. (iv) The result will help optimise the number of environmental indicators required in SEA and focus the baseline data gathering process and the subsequent monitoring of the environment. (v) It was felt that all criteria were necessary but that clear definitions should accompany each. (vi) Evaluating the indicators against the criteria using a matrix format proved useful to ensure all criteria were accounted for in the list of indicators. (vii) The final set of criteria was based on criteria widely used elsewhere, both nationally and internationally, while at the same time accommodating SEA needs and requirements.