GIS-based Strategic Environmental Assessment

The intrinsic spatial nature of environmental assessment and, indeed, most planning decisions can significantly benefit from GIS-based analyses and outcomes. GIS can provide a robust evidence-base to support consistent, transparent and informed assessments and decisions. While the uptake of GIS in SEA is growing, their application remains basic, supporting in particular certain procedural stages such as scoping or the definition of the baseline environment. Spatial analysis approaches, incorporating environmental sensitivity, impact absorption capacity and risks, as well as ecosystem services considerations are however progressively being developed and applied in the assessment of alternatives, albeit much of these approaches are linked to research rather than practice. In all cases, data quality and scale limitations remain affecting the applicability and, indeed, the outputs of GIS in SEA. Nevertheless, there is a clear trend towards a proactive adoption of GIS approaches to support SEA and the steadfast improvement of spatial data coupled with technological advancements suggest a methodological shift in SEA approaches from traditional expert knowledge matrix-based methods to more objective, consistent and geographically-explicit analyses. This chapter explores the trajectory of GIS applications in SEA, and examine how GIS can support the various SEA stages. It identifies and discusses opportunities and limitations, and concludes with a set of recommendations to effectively and efficiently embed GIS in order to optimise their application in and contribution to SEA.