Coast line evolution in Portugal since the Last Glacial Maximum until present - a synthesis

An effort has been made to assemble a data set on the evolution of coastal morphology of the West Iberian Continental Margin in Portugal, which has occur-red since the Last Glacial Maximum. In this integrated review a particular attention was given to the analyses of coastline shaping phenomena on different time scales. Several overlapping processes such as shore erosion, local sediment supply rate, climatic changes, anthropic impacts and mean sea level rise (MSLR) were identified and their combined effects assessed. The eustatic see level rise appears as a principal factor in shaping the shore line contour until mid Holocene. Since then, the non eustatic factors namely the terrigenous sediment supply rate and the dynamics of barriers and spits systems became dominant in the evolution of the near shore morphology. Since the 15th century AD, the anthropogenic activities, namely deforestation and land cultivation contributed decisively to the positive sedimentary balance in the Portuguese coastal zone. Finally, the multiple damming of the major rivers in 20th century and exploitation of sand and gravel from the river beds led to the sediment starving of the coastal zone and generalized shore line retreat. (C) 2000 Elsevier Science B.V. All rights reserved.