Aerial Imagery Analysis and Retrospective Simulation of the Impacts of Sea-Level Rise on the Coastal Wetlands of Bay of Cadiz Natural Park (Spain)

Mean sea-level rise (SLR) will change the distribution of protected coastal ecosystems such as wetlands, marshes, or dune systems. In highly modified environments where landward ecological migration is impeded by land use, this can lead to the loss of these critical ecosystems and their services. In order to take action to prevent catastrophic consequences, it is imperative that we improve our ability to predict these shifts in coastal ecosystems. In this study, we assess the suitability of the Sea Level Affecting Mashes Model (SLAMM) to hind cast the response of the Mediterranean-Atlantic saltmarshes in the Atlantic coast of southern Iberia to SLR based on the changes observed between 1956 and 2013. An aerial imagery analysis was first conducted to map the historical changes in land cover in the Bay of Cádiz Natural Park. SLAMM simulations were then performed considering the past SLR signal. The results show that SLAMM can reproduce the observed increase in the area permanently covered by water and the decline in tidal flats. While acknowledging the uncertainty derived from the various drivers of wetland change beyond the SLR, the results support the application of SLAMM in this setting and open up the possibility of applying it to predict future changes.