Changes in coastal dune systems on the Catalan shoreline (Spain, NW Mediterranean Sea). Comparing dune landscapes between 1890 and 1960 with their current status

Abstract

The aim of this paper is to assess the changes that have occurred in coastal dune landscapes in Catalonia (Spain, NW Mediterranean Sea) over the last decades. Data from photographic, cartographic, and documentary sources between 1890 and 1960 have been examined and contrasted with the current status of dunes. Our analysis measures the historical transformation of the coastal dune system according to type of transformation (disappeared dunes, dunes smaller in size and dunes that have undergone few changes) and land cover changes surrounding the beaches.At this time in Catalonia, the most extensive coastal dune systems are located in Empordà county (Roses Bay and Baix Ter Bay) and the Ebro Delta. The results reflect that the loss of dune habitat during recent decades has affected more than 90% of the Catalan beaches assessed, 60% of which have disappeared and 30% reduced in size. The most affected province is Barcelona, where disappearance of dunes has affected over 80% of beaches and no beaches present almost untouched dunes; Girona and Tarragona have also been seriously affected, with dunes disappearing from 60% to 40% of the beaches assessed, respectively. However, on a minority of beaches along the Catalan shoreline, a few dunes remain almost untouched (10%).Land cover changes surrounding the beaches show that dune habitats have been drastically reduced due to human pressure, especially urbanization and tourism-related processes. A multiple correspondence analysis (MCA) has shown that the dune systems that have disappeared are located in non-protected areas and low-lying coastal zones, whereas dunes that have become smaller in size or undergone few changes are located in protected natural areas and on cliffed coasts.