Investigações geo-arqueológicas sobre a configuração do litoral algarvio durante o Holoceno

Abstract

As part of a research project funded by the German Science Foundation (DFG. Deutsche Forschungsgemeinschaft), which took place from 2006 until 2010, traditional archaeological and modern geo-archaeological methods were used to study the changes taking place during the Holocene within the estuaries on the south coast of Portugal, the Algarve. Priority was placed on ascertaining if the development of the coastline between the Neolithic Period and the Middle Ages was more the result of natural causes (transgression, high energy events and climate) or human impact (settlement, land-use, erosion). A clear starting point was provided by the previously undertaken geomorphic research done at the Cerro da Vila (Vilamoura), where it has been possible to reconstruct the living conditions in and around the Roman harbour village once located there. Building on the results of this “on site” investigation, the first point of research was to analyse the influence of the hinterland (“off site”) on the hydrology of the coastal areas. Meanwhile the situation in selected estuaries neighbouring the Cerro da Vila and the related drainage areas was studied in order to identify the fundamental developments of the entire western Algarve coast (Barlavento). By comparing the different effected geo-archaeological archives in the Algarve it should become possible to differentiate erosional phases caused by changes in climate or high energy events from mostly local factors, which are induced by anthropogenic land-use; therein lies the hypothesis. The palynological studies were especially useful here in determining the human influence on the land use of the Algarve coast. The aim of the accompanying archaeological study was to draw chronologically differentiated distribution maps showing the development of human settlement between the Neolithic Period and the Middle Ages. The results of this interdisciplinary study show that the silting of the large estuaries on the southern coast of Portugal can be seen as a result of anthropogenic erosion that had already begun in the Bronze Age and reached its peak during the Roman Period. Furthermore geo-archaeological investigation shows a very strong impact, with several effects on the settlement patterns of the region (harbours, fishing-villages, murex-production, etc.), during the time of the Roman Empire.