This research aimed at establishing whether spatial data and Geographic Information Systems (GIS) can contribute to Strategic Environmental Assessment (SEA). To achieve this, an integrated GISEA approach was developed and applied to a number of spatial planning SEAs in the Republic of Ireland. The practical applicability of the approach was examined, evaluating the potential benefits derived from using spatial data and GIS in SEA and assessing the potential barriers to an effective GIS use. The implementation of the SEA Directive incorporated a new dimension into plan-making by calling for the assessment of potential environmental effects that may derive from implementing a plan. The intrinsic spatial nature of land use plans poses specific requirements on the tools and assessment methods used. GIS – with their capacity to visually display and spatially assess information- have the potential to support SEA processes. Moreover, GIS tools can tackle the spatio-temporal dimensions that conventional assessment methods (e.g. matrices and checklists) fail to address. To explore the validity of these arguments, GISEA was applied to seven Irish development plans. These were supported by interviews with the planners and technicians involved, and through review of published SEA environmental reports. The case studies demonstrated that GIS can provide the mappable aspects of SEA; they facilitate the process by enhancing understanding of environmental and planning considerations, and improving the accuracy of assessments. These observations concur with published literature on the predicted benefits of applying GIS at various environmental assessment levels. Nevertheless, the results revealed that framework and procedural difficulties remain (e.g. institutional arrangements and technical data issues). These are more apparent at higher planning tiers and in certain SEA stages such as public participation. The contribution of GIS largely depends on scope for spatial information, availability and quality of relevant datasets, and willingness of involved organisations to facilitate data provision and disclosure. Therefore, formulation of spatially-specific land use plans and improved data accessibility and quality can contribute to an effective GIS use in SEA. Further research and practice are required to disclose the full potential of GISEA, but the work-placement aspect of this research has already had a direct impact on the level of GIS use in Irish SEA practice.
free text keywords: spatial data, GIS, SEA, land use, plans, case studies, Ireland, Geotechnical Engineering, Other Engineering