Physiographical evolution and human occupation of the Mondego estuary area (central west coast of Portugal) since 1947.

Abstract

Since 1960, the coastal zone near the town of Figueira da Foz experienced a very quick morphological change caused by intense human activities in the Mondego drainage basin and in the highly dynamic coastal zone. The huge jetties built to improve port access conditions, produced the main effects on the coastal morphology. The main targets of this study are the physiographical evolution and changes in human use of the area, performed through analysis of aerial photographies coverages, topographic maps, bibliography and field observations. The most relevant changes are: I) large and rapid changes of the distai estuary and coastline morphodynamics mainly as a result of extensive harbour developments -large accumulation of sand against the northern jetty while the erosion of beaches located southwards, deprived of sand, led to the construction of groins and seawalls; 2) modifications in the sedimentary systems of the river, induced by engineering works in the fluvial sector (construction of dams and artificial channels; sand mining) and estuary (including dredging); 3) expansion of urban and industrial areas over the estuary and coast; 4) development of aquaculture and rice culture, but decrease of traditional salt exploitation ("salinas") and other agricultural types; 5) widespread erosion the coastline, mainly caused by a strongly negative sedimentary budget. Planning and management of this beautiful coastal zone, including monitoring studies, should include restrictions on human occupation in arder to preserve and allow the natural evolution of the landscape.