Erosión costera en yacimientos arqueológicosGuidorio Areoso, Ria de Arousa, Galicia

Resumo

Guidorio-Areoso is a small islet surrounded by rock shoals at a low water depth. It is formed by a granitic outcrop covered by a dune complex, with a sand lobe elongated to the north. Intense evidences of human occupation between Neolithic and Bronze Age were detected at the site, including funerary use and seasonal occupations. During the last decade new archaeological evidences were exposed by marine erosion introducing an important risk of destruction to the structures discovered. Using a set of aeroespatial information from 1945 to 2013 we found a morphodynamic behavior characterized by the rotation of the north sand lobe, with a maximum rotation of 14.15º between 1956 and 1984. Between 1984 and the year 2000 the north sand lobe and dunes remained disconnected from the rock island, maintaining the rotation but now with a progressive shift to the east. Between 1945 and 2013 the extension of the vegetated dunes of the north lobe were reduced in 28%. Although the erosion of the dune fronts has been related to the rising sea-level, the rotation of the sandy lobe implies sand movements that can cause the erosion of the beach and the dune fronts.