Erosion in Buenos Aires province: Coastal-management policy revisited

ISLA, F.; CORTIZO L C; MERLOTTO, A; BERTOLA G R; PONTRELLI ALBISETTI; FINOCHIETTI CECILIA

OCEAN & COASTAL MANAGEMENT

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2018 vol. 156 p. 107 - 116

0964-5691

As the Buenos Aires Province coastline is dominated by a longshore transport from south to north, ob-structions performed at the beginning of the 20th century originated the width reduction of somebeaches. Fields of groins were constructed without a master plan; therefore, more obstructions caused adramatic decrease in the longshore sand supply. These defense alternatives were only applied in thecounties of the southeast of the province (General Pueyrredon, General Alvarado, Mar Chiquita), close tothe quarries, and with resistant abrasion platforms. Northern beaches (Villa Gesell, Pinamar and Partidode la Costa), on the other hand, are natural with a dissipative morphodynamics. Where the coastal routeis close to active cliffs, riprap structures were constructed parallel to the coastline. Today, the south-eastern coast remains with the higher erosion rates of the Buenos Aires coastline. With the aim of aerialand satellite photographs, and images, erosion rates were calculated. In order to analyze the success ofcoastal defenses, comparisons were established according to two intervals: 1960e1980, and 1980e2008.Defense structures have contributed to the decrease in the erosion rates in some areas; in other areas, therates have increased due to the drift obstruction. In some critic areas, and considering present erosionrates, future positions of the coastline were simulated for the next 20e30 years. At the same time, thereare new unexpected problems derived from a project to construct detached breakwaters that were notcompleted, and considering jetties that were constructed without a previous impact-assessmentanalysis.