QUANTIFYING THE IMPACT OF THE CONSTRUCTION OF A NATIONAL HIGHWAY ON LANDSCAPE CONTINUITY AND FRAGMENTATION OVER TWENTY YEARS – A COMPARISON OF THREE SPATIAL APPROACHES

Construction and paving of road infrastructures is on the rise globally. Roads have many negative impacts on the environment, including changes and damages to landscape connectivity, fragmentation and disrupting of ecological corridors, loss of habitats, air pollution, noise pollution and light pollution. Here we aimed to examine the impacts of the construction of a major road (national Highway 6 in Israel, 188 km long) on landscape fragmentation. To this end we mapped the land cover at three-time steps: 1997 (before the construction of the road began), 2009 and 2019, quantifying both patch-based metrics (using Frgastats), the continuous metrics of landscape connectivity (using Circuitscape) and landscape continuity, adapting a before-after-control-impact methodology. Analyzing changes in those metrics for sections of the road based on their time of construction and on the distance from the highway, we found that most changes took place within a distance of up to 1 km from the new highway, starting after road construction began. We also found that the patch-based metrics and the continuous metrics were weakly correlated. We conclude that each of those different approaches has its merits and limitations, that they are complementary and that jointly they provide us with better understanding of landscape changes.