Coastal erosion in temperate barriers: an anthropized sandy beach in Buenos Aires, Argentina

GARZO PEDRO; SANCHEZ CARO LEONARDO; MOJICA MARCIA

JOURNAL OF SOUTH AMERICAN EARTH SCIENCES

PERGAMON-ELSEVIER SCIENCE LTD

Lugar: Amsterdam; Año: 2023

0895-9811

Coastal erosion is a common issue in urbanized areas located on sandy barriers in Latin America, making themhighly vulnerable to both natural and human induced disasters. This pose a significant threat to the long-termsustainability of these coastal systems. The main objective of this study was to evaluate the medium-termshoreline evolution of a highly-anthropized beach sector located within a coastal barrier system of BuenosAires, Argentina. For this purpose, a geospatial analysis based on aerial imagery and high-resolution satellite datawas conducted for the 1965–2021 period. Additionally, the study aimed to identify critical erosive sectors and toprovide estimations for the near-future shoreline evolution of these beaches. The results showed contrastingpatterns, with sectors presenting shoreline retreat rates up to 0.7 m/yr while others demonstrated accretion ratesexceeding 0.6 m/yr. Despite these along-shore variations in erosion/accretion balances, more than 70% of theshoreline presented an erosional trend for the studied period. This led to the identification of an erosional hotspot covering 30% of the urbanized waterfront. Furthermore, the 2030 forecast suggests that a highly urbanizedbeach sector could suffer a shoreline retreat of about 20 m. These results could be directly linked to the historicalland use/land cover changes, mainly related to dune stabilization processes and to the implantation of urbansurfaces. At this point, erosive patterns could be mainly caused by local cross-shore imbalances due to theseanthropogenic disturbances. It is expected that the results of the present study will serve as a basis for coastalmanagement policies, and the proposed method will be a useful tool for assessing coastal erosion hazard.