Natural Protection of the Coast: Mapping Coastal Protection Service Provided by Nearshore Marine Habitats

Abstract

Given the global climatic changes, coastal zones are more vulnerable to sea level rise and climate extreme events. Nearshore marine habitats, such as sand dunes and salt marshes, have the ability to naturally provide protection to floods, storm waves and erosion, which has been considered as an important ecosystem service. The NW of Portugal is part of the Iberian Peninsula ecoregion, receiving the influence of three oceanic water masses. Its coast features rocky and sandy beaches and several estuaries, some of them under environmental protection. This area is highly urbanized, hosting the second major city of Portugal (Porto) and supporting several human activities, with tourism exponentially growing over the last decade. The coastal zones are prime real estate areas and new tourism economic opportunities are growing fast, stressing the need to manage human activities without compromising ecosystem health and the maintenance of ecosystem services, namely coastal protection. Integrated in the MarRISK project, different modelling tools will be combined to assess coastal protection provided by the natural habitats, like sand dunes and salt-marshes of NW Portugal. Using different habitat features, as bathymetry, topography and waves data obtained within the MarRISK project, with vegetation and land-cover profiles, the protection service provided by sand dunes and salt-marshes will be assessed. Output maps will represent the amount of avoided erosion or inundation along the NW-Portuguese coast, in the presence/absence of the nearshore marine habitats. These maps will be important to help decision-makers understand the importance of protecting these natural habitats.