It’s not only the sea: a history of human intervention in the beach-dune ecosystem of Costa da Caparica (Portugal)

Abstract

Costa da Caparica, located south of Lisbon, has been since the 1960s the favourite beach of the population of the Portuguese capital. The bridge over the Tagus river (1966), connecting the two margins, has facilitated the access to that wide beach of sand and dunes. Due to its natural features and proximity to Lisbon, Caparica become a highly populated area, where different social and economic activities compete for the use of the available space, increasing pressure upon the local ecosystems. The situation is even more problematic, because that littoral has been deeply affected by coastal erosion from the 1950s onwards. Authorities have been dealing with the issue using groynes and artificial beach nourishments. Since 2015, the Municipality of Almada is investing in the rehabilitation of the dunes of the beach of S. João, placing fences to retain the sand and planting vegetation. This programme is particularly interesting from a coastal management history point of view, because these dunes have been the object of many interventions with different purposes, but what was done and why is not very well known. The aim of this article is therefore to present the results of a historical research about human intervention in Costa da Caparica and, particularly at S. João beach, starting in the 19th century, with the first dunes’ survey, the afforestation experiences and the construction of a drainage system. This paper offers a long-term perspective on the socio-evolution of these hybrid environments. Results and discussion show how dunes were trimmed by the works carried out and the reasons that laid beneath these. Revealing the ideas and values, the social, economic and political pressures, that across the years and within the same time period, shaped management strategies and landscapes. Keywords: Environmental History; Dunes Rehabilitation; Afforestation; Wetlands; Coastal Erosion.

Evolutionary Trajectories of Coastal Sand Barriers along the West Portuguese Coast during the Holocene

“…At present, this coast is one of the main hotspots of erosion within the Portuguese coast related to the dredge activities of the Tagus navigational channel [14]. Human occupation is recent (i.e., by the end of the XVIII century, occupation was seasonal) and concentrates within the northern part of the coastal plain, originally oriented to fishery and agriculture purposes [27]. In 1830, the occupation of this area was legalized.…”

“…The dunes appear to migrate southward, forming 100 m wide and 4 m high transverse ridges. The mobile dunes were artificially fixed through the implementation of afforestation measures aiming at transforming the area into fertile lands to use for agricultural purposes [27]. The southern limit of this mobile dune field is characterised by small and isolated parabolic dunes migrating to the south.…”

Is the Sea the Enemy? Occupation and Anthropogenic Impacts at Costa da Caparica (Portugal)

“…Dunes are also notorious in this area and the dune coastline is constituted by diverse vegetation for this type of ecosystem; namely, Elymus farctus V., Eryngium maritimum L., Euphorbia paralias L. and Ammophyla arenaria L. An extensive zone of inland coastal dunes also includes vegetation such as Acacia and Pinus, which were planted between the late 19th century and the first half of the 20th century. This beach-dune system, which is the natural defense against the sea, has been affected by diverse anthropic actions, such as illegal building, sand extraction, and urban growth, among others [35,36]. Climatic conditions of this area are marked by dry and hot summers with temperatures that can reach between 23 and 29 degrees Celsius near the ocean and between 29 and 32 degrees Celsius near the Tagus River.…”

“…It is interesting to note that regulations were imposed to restrain the construction of wooden houses or other kinds of uses of the Costa da Caparica beach, which confirms that not only were people settled there, but that human occupation was growing [68] (p. 49). Mainly dedicated to fishing, the village grew and expanded in the following centuries [27,28,31,32,34,35]. Costa da Caparica belonged to Monte da Caparica parish until the year 1926 when it was integrated into the parish of Trafaria (Figure 1C).…”

“…On the other hand, local historiography does not offer any data about such matters [27][28][29][30][31][32][33][34]. The only historical analysis that could help to identify such matters concerns the occupation of this area after the 19th century, explaining the human-made landscape changes and problems concerning such dynamics [35]. Therefore, there is a research gap in the larger chronological approach that needs to be addressed.…”