A (Happy) Story of Coastal Erosion and Dunes

When I took the first picture (left) in 2008, this beach bar in Costa de Caparica, Portugal, was severely threatened by coastal erosion. However, against all expectations, a picture taken in the same place after sixteen years (right) shows that the beach bar is still there, but now surrounded by a large and robust dune… So, what happened in the meantime? That’s the story I want to tell.

São João da Caparica (Almada, Portugal) beach-dune system in 2008 and 2024.

After the storm, coastal authorities agreed to proceed with a previously scheduled beach nourishment programme, comprising the placement of large quantities of good quality sand, from the regular dredging of the navigation channel of Lisbon harbor, to mitigate coastal erosion. This was done in 2008, 2009, 2014, and 2019, followed by the analysis of the performance and lifetime of these interventions. After the 2014 intervention, sand fences and vegetation were introduced in this area under the ReDuna restoration project, developed by the municipality of Almada. This intervention, in compliance with aeolian processes that mobilized sand from the previously nourished beach, led to an in situ growth of the dune both in terms of height and of volume, progressively shifting the coastline approximately 30 meters seaward to date.

This “new dune” acted as a sand buffer, improving protection to upland structures and infrastructures from the effects of storms, while also restoring and preserving environmental and recreational values of this valuable beach-dune system.

Evolution of coastlines is uncertain and hard to predict. The default position is to assume that present day coastal change will persist in the future, most likely exacerbated by climate change effects—namely sea level rise and increased “wave storminess.”

This story brings us another perspective: instead of fighting against nature we can build with nature using its own resources (e.g., sand) and its natural forces (such as the wind) to temporarily buy time for a battle that, in the end, is unlikely to be won.

—Celso Aleixo Pinto