Gap analysis is used to measure the degree to which conservation networks are complete. Usually, gaps are identified and evaluated through an assessment of representation, then filled using a site selection methodology. The landscape-based gap analysis tool developed by WWF-Canada addresses the first part of this definition by determining how well ecological diversity is represented in protected areas and protected area candidates. The gap analysis tool is implemented as an automated GIS routine and can inform ecoregion conservation planning by testing reserve design options that have been selected through multi-criteria methods, such as overlay approaches, High Conservation Value Forest assessments, or site-selection algorithms.
WWF-Canada uses a spatial framework for gap analysis based on a hierarchical arrangement of enduring features within natural regions. Each enduring feature represents a unique landform within each of the natural regions, which are themselves characterized, in part, by climatic characteristics. The gap analysis measures the degree of ecological representation within each enduring feature by protected areas.
An automated routine, running as an extension in ArcGIS, has been developed to conduct the gap analysis. The analysis can even be used in real-time conservation planning in workshop settings, as it often takes less than 15-30 minutes to complete an assessment at the scale of one of more ecoregions. Furthermore, the data required for the assessment are readily available online.