Setorização do subsistema sul da lagoa da Conceição, Santa Catarina

Abstract

The aim of this work is to propose a regionalization of southern Conceição Lagoon subsystem, located at the Santa Catarina Island-SC, based on its grain size, compositional and physiographic characteristics. The subsystem is part of a chocked lagoon, being connected to the remaining lagunar body by a narrow 3.5 m deep channel on its northern portion. It is surrounded by granitic rocks at west and by quaternary sedimentary deposits at east, north and south. Sediment samples were sampled at 16 regularly distributed points and were processed to determinate biodetritic carbonate, organic carbon content and conventional grain size parameters. Continuous surfaces of the variables were obtained through kriging interpolation. A bathymetric map resulted from the interpolation of 2.464 depth points digitalized from charts at the scale of 1:2.000 m. Individual sectors were identified based on data integration and spatial analysis of sedimentologic and bathymetric parameters. The integration of the variables through cluster analysis yielded the regionalization of the subsystem, were three depositional environments were defined: a predominantly sandy, a sand-muddy and a muddy environment. Besides these three, a fourth transitional environment situated between the banks and deeper areas was recognized. The muddy environment was subdivided in three distinct sub environments: deep muddy, sheltered muddy and organic muddy. Their limits were set through the analysis of the spatial behavior of sediment descriptors and bathymetry. From the results it is possible to conclude that the spatial and cluster analysis of morpho-sedimentological descriptors was efficient on the regionalization of the environment in study, even considering the small number of sediment samples.

Identification of coastal natural disasters using official databases to provide support for the coastal management: the case of Santa Catarina, Brazil

“…This result corroborates previous research (Gares et al 1994;Camargo et al 2000;Rudorff et al 2014),…”

“…Furthermore, the greatest morphological changes on beaches usually occur during processes of sudden energy transfer to the system, such as during storm surges. Such phenomena are generated by the combined action, to a greater or lesser extent, of astronomical tides, large waves, and winds blowing towards the coast that cause the sea level to rise (Carter 1988;Rudorff et al 2014). According to these authors, negative effects associated with storm surges occur throughout the coastal zone of Santa Catarina, which are predominantly the result of disturbances caused by coastal storms associated with extratropical cyclones and the passage of cold fronts.…”

“…Furthermore, several researchers discuss the global increase in the occurrence of extreme events in the last decade (Ruggiero et al 2010;Coco and Ciavola 2017;Kim 2020;Lin-Ye et al 2020;Chen et al 2021;IPCC 2021;Nicholls et al 2021;IPCC 2022a;IPCC 2022b;Lockwood et al 2022). This is also evidenced in the southern region of Brazil (Camargo et al 2000;Marengo et al 2009;Rudorff et al 2014), which leads to an intensification of natural disasters mainly in coastal areas without natural protection, such as dunes, wetlands, and mangroves (Bulhões 2020).…”

Agentes naturais e antrópicos modificadores da qualidade da água e dos sedimentos nas áreas marginais da Lagoa da Conceição, SC

“…Nestes trechos foram encontrados teores orgânicos de até 40% (Gré & Horn Filho, 1999;Rudorff et al, 2005). Esta diferença composicional entre as áreas rasas e mais profundas deve-se provavelmente à maior hidrodinâmica das primeiras, fator que dificulta a deposição de sedimentos finos e a adsorção de compostos orgânicos.…”

Hydrodynamic and Wave Responses During Storm Surges on the Southern Brazilian Coast: A Real-Time Forecast System

“…As a representative case of the aforementioned susceptible condition, the State of Santa Catarina, in Southern Brazil, is particularly vulnerable to storm surges. It is estimated that from 2000 to 2010, 17,000 people have been affected by such events in the state, with millions of dollars being lost in property damages; among the state's municipalities, Florianopolis, which is the state capital, is by far the most impacted city [34]. Once a country has a reliable coastal flood forecast system, decision makers can issue appropriate warnings, estimate potential damages, implement evacuation strategies, and manage emergency shelters [35,36].…”