Taxas de assoreamento e a influência antrópica no controle da sedimentação da Baía de Antonina - Paraná

Abstract

The maritime channel that yields access to Paranaguá and Antonina harbours requires periodic maintenance of its security maritime depth. That maintenance requires dredging and disposal operations. This study aims at increasing the knowledge of the bathymetric dynamics of Antonina Bay, correlating historical survey data to actual data. The results of this comparison show an intense shoaling on Antonina Bay, mainly on the upper portion and on the margins, where extensive tidal flats have developed. The total sediment volume deposited in the period between 1901 and 1979 was around 60 × 106 m3 , reflecting a sedimentation rate of approximately 2,6 cm/year. Anthropic influence such as the connection between the rivers Capivari and Cachoeira for hydroelectric purposes, deforestation on river catchment areas at Serra do Mar, and activities of dredging and disposal, hints at a significant acceleration of the silting process of this portion of the Paranaguá Bay Estuarine Complex.