Abstract

LISBOA, Paulo Victor  and  FERNANDES, Elisa Helena. Anthropogenic influence on the sedimentary dynamics of a sand spit bar, Patos Lagoon Estuary, RS, Brazil. RGCI [online]. 2015, vol.15, n.1, pp.35-46. ISSN 1646-8872.  https://doi.org/10.5894/rgci541.

Known to be transition zones between the sea and the mainland, estuaries are recognized for their socio-economic and ecological importance as well as their complexity and vulnerability to anthropogenic influences, harbor activities included. It is reasonable to consider that these influences produce changes in the dynamics of the region, resulting in modifications related to the biota, sediment transport, and flows between the estuary and the adjacent coastal zone. The possible changes in the sediment budget of the Patos Lagoon estuary can affect fragile features present in the estuary such as sand spits. The objective of this work is to evaluate the effect of the modernization work carried out at Rio Grande Harbor access channel on a specific sand spit called Pontal Sul as an indicator of the sediment dynamics alteration in the Patos Lagoon estuary. The study is based on numerical modeling experiments with the TELEMAC-3D model and remote sensing techniques (Quickbird images). Results indicate that the Rio Grande Harbor modernization work changed the Pontal Sul erosion and deposition rates and longitudinal growth. The results suggest that the modification carried out at Rio Grande Harbor access channel changed the Patos Lagoon sediment dynamics.

Keywords : Anthropic influence; erosion; deposition; harbors; numerical modeling.

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