بکارگیری سیستم های اطلاعات جغرافیایی برای حمایت از ارزیابی زیست محیطی استراتژیک : فرصت ها و محدودیت ها در زمینه برنامه های ایرلندی استفاده از زمین

The strengthening of spatial database infrastructures, further promoted by the INSPIRE Directive adopted in 2007, has led to an increased use of spatial data in planning and decision-making. Given that land-use plans are intrinsically spatial, such evidence and approaches can significantly benefit plan-making. A spatial framework could especially support the specific Strategic Environmental Assessment (SEA) aspects of the plan-making process. Spatial tools such as Geographic Information Systems (GIS) are particularly well-placed to support the environmental integration sought in SEA by providing evidence through the spatial assessment of multiple environmental datasets. Moreover, GIS bring the opportunity to augment conventional assessment techniques (e.g. matrix-based assessments) by acting as visual mediators of spatial knowledge and by providing an effective tool for the spatial and temporal analysis of environmental impacts. This paper presents a GIS-based approach to SEA (GISEA), and analyses the above premise by evaluating the barriers, limitations, opportunities and benefits of its implementation. The GISEA approach has been applied to seven development plans of differing scales in the Republic of Ireland. The results of the case studies revealed that current issues in SEA (e.g. restricted time-frames and institutional arrangements) condition the implementation of a GIS-based approach. Moreover, GIS expertise, data accessibility and quality remain limiting factors to an effective GIS application in SEA. However, the results also confirmed that GIS have the potential to increase the objectivity and accuracy of the assessment, enhance both the understanding of environmental and planning considerations and the delivery of information, and, therefore, help to improve the effectiveness of SEA practice.

Geographic Information Systems (GIS) are increasingly used to support decision-making in spatial planning. Given that development plans commonly link land use to location, spatial evidence and approaches can significantly benefit plan-making. Such a spatial framework could also support the specific Strategic Environmental Assessment (SEA) requirements of the plan-making process. Directive 2001/42/EC (CEC, 2001), commonly known as the SEA Directive, sets the requirements for the environmental assessment of plans and programmes (PP) that are likely to have significant environmental effects. SEA can be defined as a structured and participative procedure containing a set of tools to assist in the integration of environmental considerations and promote informed decision-making at PP level (González, 2010). The procedural requirements of the SEA Directive are commonly fulfilled through a series of actions undertaken during the plan-making process (namely: screening and scoping, description of PP alternatives, environmental baseline description, environmental assessment, mitigation measures, public consultation, and monitoring). The SEA process runs in parallel with plan-making, and culminates in the preparation of an Environmental Report (ER) to inform decision-making. The methods and techniques applied in SEA vary (e.g. expert judgements, matrices, mapping and modelling). Matrix-based assessment techniques have probably been most widely used in SEA practice to date (Fischer, 2007 and Therivel, 2004). Although matrices allow easy identification of conflicts and trade-off between PP and environmental objectives, they have a degree of subjectivity (Therivel, 2004), and often fail to address the spatio-temporal dimensions common to environmental and planning issues (Skehan and González, 2006 and Vanderhaegen and Muro, 2005). GIS can overcome some of these restrictions by identifying the spatial and/or temporal variability amongst impacts (Patil et al., 2002), and have the potential to augment conventional techniques by providing spatial evidence to both the assessment and the plan-making processes (González et al., 2008a and González, 2010). The use of spatial data and GIS in environmental assessment is promoted by Directive 2007/2/EC (CEC, 2007), for the creation of an INfrastructure for SPatial InfoRmation in Europe (INSPIRE). The INSPIRE initiative has also promoted the introduction of GIS into other environmental legislation, including the Water Framework Directive (CEC, 2000) and the Noise Directive (CEC, 2002), both of which require submission of certain geographic information in map form. It is anticipated that such an infrastructure will itself promote further use of spatial data by making relevant and quality geographic information available for the formulation, evaluation and monitoring of PPs (CEC, 2005). Although the SEA Directive does not formally require the use or generation of spatial datasets, it is considered that their application can provide several benefits when compared to traditional methods (González, 2010 and Vanderhaegen and Muro, 2005). Given the wide spatial and temporal scope needed for the SEA of PPs, the capabilities of GIS can confer significant advantages in the prediction and evaluation of spatially distributed and/or cumulative impacts. GIS facilitate the preparation of maps and, thereby, present a SEA support tool to illustrate and analyse data (Therivel, 2004), particularly in land use planning (Fischer, 2007). Presenting baseline data in graphic form improves the delivery of information, enhancing the understanding of the distribution, patterns and linkages between relevant environmental factors (Department of Environment, Heritage and Local Government (DEHLG), 2004a, Office of the Deputy Prime Minister (ODPM), 2005 and Vanderhaegen and Muro, 2005). Therefore, GIS have the potential to facilitate a more robust spatial analysis as they enable integrating various datasets and visualising the juxtaposition or cumulative nature of different impacts (Harrison and Haklay, 2002). In addition, they enable the reuse of “old” datasets; combining them with current information incorporates a time-scale which facilitates the prediction of the cumulative effects of plans and projects over a number of years (Vanderhaegen and Muro, 2005). It can be argued that these advantages have the potential to lead to more transparent decision-making for spatial planning since decisions can be demonstrably based on spatially-specific and objective evidence (Skehan and González, 2006). Nevertheless, a number of constraints affecting the effectiveness of GIS have been reported, including data availability, accessibility, and costs, and data quality in terms of scale, completeness and currency (e.g. Rybaczuk and MacMahon, 1995, Vanderhaegen and Muro, 2005 and van Loenen and Onsrud, 2004). The exploration of empirical applications of GIS in SEA is limited, with most published literature focusing on one of the various SEA stages (e.g. Geneletti, 2008 and Haklay et al., 1998). Similarly, the use of GIS within environmental assessment is underdeveloped in the Republic of Ireland (‘Ireland’ from hereon), their use being largely limited to mapping operations. Such limited experience probably constrains effective decision-making, given the documented advantages of applying GIS in environmental assessment and the opportunities for its incorporation. This paper focuses on assessing the capability of spatial data and GIS for enhancing SEA and examines the factors that enable/impede their effective application.

This research has demonstrated that spatial data and GIS can play a significant role in supporting SEA by providing spatial evidence, integrating and assessing multiple issues and values in a more objective and precise manner, and conveying the assessment outputs in a concise and visual manner to improve the understanding, all of which arguably should have a positive effect on drafting the plan. Nevertheless, the research has also revealed that effective GIS application is currently constrained by several contextual limitations and technical barriers. The current approach to strategic planning in Ireland restricts the general applicability of the methodology, since strict time-frames and prioritisation of planning tasks hinder timely data gathering, and objectives and policies are often formulated in broad and non-spatial terms. Moreover, once datasets are gathered, these may still contain inconsistencies that impinge upon their readiness. Belated incorporation of spatial datasets commonly leads to inadequate provision of information at decisional stages in the planning process. Reservations over copyright and data publication can also affect the timely publication of certain spatial datasets, and limit public participation GIS (although this is also affected by underdeveloped spatial awareness and IT knowledge). Procedural barriers also hinder GISEA effectiveness. Issues of data availability, accessibility, compatibility and quality (including the common lack of indicator values), and more importantly lack of metadata, can affect all SEA stages. These aspects can have serious implications for the reliability of GISEA outputs. Acknowledging any data limitations in the ERs, and recognising the potential risk of providing unreliable GIS and, therefore, SEA outcomes can enhance transparency and help validate the credibility of results. Achieving the full capacity of GIS to affect decision-making goes beyond resolvable issues of spatial dataset quality and the validity of GIS-based assessment outcomes. Overcoming procedural constraints through full access to current and accurate spatial datasets and their adequate management would not automatically make SEA better. Framework issues prevail in the form of institutional arrangements, affecting both the applicability of GIS and, in particular, the effectiveness of SEA. Investigation of decision-making cultures in Ireland would help better understand current limitations to proactive environmental integration. Further research is required to devise measures to strengthen GIS approaches in the planning system, and to fully incorporate them into SEA (including the more complex stages of mitigation and monitoring). Additional research is also required to advance understanding on spatial data issues. In particular, undertaking a sensitivity analysis of existing Irish spatial datasets will help establish their quality and validity for SEA; in this regard, the effects that a national repository and data quality mechanism would have in the implementation and applicability of GIS also need to be explored in detail. Notwithstanding the extensive research undertaken in public participation GIS, it is considered that future research should focus on devising mechanisms to effectively factor in public perceptions into SEA. Research and practice need to be expanded to ascertain the full potential of GISEA approaches, but the practical applications embedded in this research have already had a direct impact on the level of GIS use in Irish SEA.