An approach to coastline evolution as a tool for coastal management: case study of La Pedrera—Cabo Polonio Bay (Rocha, Uruguay)

Abstract

A study of the position of the coastline was performed from the recent past (50 years) to Holocene ages (about 5000 years ago) in La Pedrera–Cabo Polonio coastal sector, in the southeast of Uruguay. Some persistent geoforms, such as marshes, located at very low elevations present lowest displacement of the recent coastline. Other recent landscapes, such as coastal gullies, developed on Late Pleistocene sediments are associated with a progradational coast in the short term. The geomorphological cartography was a useful tool for coastal management in the scenario of 10 cm sea-level rise per century and a coastal retreat of about 1 m per year. The analysis of coastline evolution provides information to assess the best measures to prevent coastal erosion and identify vulnerable areas. The presence of an escarpment (paleo coastline) located around + 10 to + 5 m above the current sea level appears to be the most appropriate criterion of minimum setback distances from current coastlines for constructions.