A GIS methodology for assessing ecological connectivity: application to the Barcelona Metropolitan Area

We developed a new methodology for the assessment of landscape and ecological connectivity at regional scale. This method has been entirely formalized using mathematical language, is supported by a topological analysis of a 1:25,000 scale land use map, and has been developed using Geographic Information Systems (GIS). The method allows the elaboration of a diagnose of the connectivity of terrestrial landscape ecosystems, on the basis of a previously defined set of ecological functional areas, and a computational cost-distance model which includes the barrier effect. This last component takes into consideration the type of barrier, the distance impact, and the adjacent land use and vegetation type. We defined two new compound indices: one for ecological connectivity and another for the barrier effect. The practical interest of our model is that it not only allows a cost-effective assessment of the current situation, but it has predictive capabilities, allowing the quantitative assessment and comparison of the impacts resulting from different planning scenarios or different infrastructure alternatives on the landscape and ecological connectivity.