Relações entre a morfodinâmica e a utilização em trechos da costa oceânica da Ilha de Santa Catarina, SC, Brasil

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

This Doctorate dissertation analyzes the relation among morphodynamic characteristics of oceanic sandy beaches and the use of its coast. The study area is the oceanic coast of Santa Catarina Island, in Florianópolis, SC, southern Brazil. First of all, data about forty beach profiles, which had been monitored, were collected. Several parameters were analyzed; it enabled grouping the types of beaches by using multivariate statistical Techniques. Three groups, or rather, types of beaches, were identified. Beaches with fine sand that were sheltered from the high energy of waves by rocky promontories comprised Group 1. They have low declivity in the subaereal volume, lack a defined submerged sandbank, or a Low Tide Terrace, and are morphologically the most stable ones among the beaches under investigation. Beaches with fine sand, exposed to moderate and high wave energy were in Group 2. They have low/moderate declivity on the beach face, Intermediate to Dissipative morphodynamic stages in the subaqueous area and moderate/high morphological variability, even though some have similar characteristics to the ones included in Group 1. Beaches with coarse sand, exposed to moderate/high energy of waves were in Group 3. They have high declivity on the beach face, with a Reflective face, but may present a variable sandbank with intermediate morphodynamic characteristics on the mean beach and high morphological variability. Besides, the shore was classified according to its use and preservation, and natural shores # some are going through an urbanization process and others are wholly urbanized # were differentiated. In addition to this, criteria regarding setback and urban structure were defined. Natural shores occur along fields with transgressive dunes and barrier/lagoon system which have been protected by laws, and where urbanization has preserved the area that faces the sea. Shores which are going through an urbanization process are usually located near main urban areas but also represent areas where touristic developments have been planned. Shores with consolidated urbanization have quite suppressed physical-natural characteristics due to the historical process of human occupation; most of them are former fishery communities where horizontal urbanization without setbacks domains the shore nowadays. Taking into account 40 stretches of oceanic shore under analysis, those with lower hydrodynamics energy and morphological variability are usually urbanized or going through this process. In general, they are structured on the beach limits, i. e., with no setback. Furthermore, these analyses pointed out that the most vulnerable stretches regarding coastal erosion processes are the ones located in areas that are sheltered from the direct action of high energy waves. In the most exposed areas on the shore of Santa Catarina Island # morphologically more variable, in theory # there are no major signs of vulnerability to erosion due to the fact that, in general, their natural stages have been preserved.

ASSUNTO(S)

praias costa - santa catarina, ilha de (sc) - proteção geografia geografia

ACESSO AO ARTIGO

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