Morfologia e sedimentologia das praias do litoral sul do municÃpio de Olinda - PE

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The littoral of Olinda has spaces with coastal erosion since the last century. Trying to soften the erosion and stabilize the shoreline, a good range of engineering techniques were used in the last 88 years. During the 60s decade were made two breakwaters semi submerged in front of the Carmo beach and 38 groins along the 1,8 km of the Bairro Novo beach. The works accomplished protected and stabilized the shoreline. However, they were inefficient in the regeneration of the beach. For that reason studies which comprehend its morphologic and sedimentary behavior are necessary to have a better planning of the coastal protection actions and maintenance of the works which already exist. With this purpose, this research elected Carmo and Bairro Novo beaches for the realization of the morphologic and sedimentologic studies. For that purpose six topographic profiles were monitored from may/06 to October/07, where three of them were in the Carmo beach ((PO1a, PO1b e PO1c) and three in the Bairro Novo beach (PO2, PO3 e PO4). At the same time it was made a collection of the superficial sediments along the profiles. Aiming to know the distribution of the sediments deposited between the groins of Bairro Novo beach, samples of sediments were collected in two different moments as well. It was also determined the equilibrium beach profile, up to the samples with or without the presence of CaCO3. From the submerged portion of the cells 21, 22 and 23. For the Carmo beach the following results were observed: the most morphologic variations were observed on the PO1a e PO1c profiles, on the region of the upperbeachface. This compartment presented the most variations in their sedimentologic parameters. The PO1a e PO1c profiles suffered erosion in 2007, offering a minor sedimentar volume this year. This profile presented a positive sedimentar balance in its volume of sediments in 2007. For the Bairro Novo beach it was observed the following results: O PO2 e o PO3 showed an erosive tendency during the time it was monitored. The PO4 was the most stable profile from the Bairro Novo beach, and it presented the most stable and developed region of backshore and it was the only one with positive sedimentary balance. In spite of the great accumulation of the sediments in the sub aerial portion of these profiles, the equilibrium profiles determined showed that in this place there is a deficit in its sediment storage. The PPE determined with CaCO3 appeared more debased than the determined without CaCO3. In the central portion of the Bairro Novo beach are located the most cells which do not present disposition of sediments. In the North sector are located the cells which present coarse. In this part there openings between the beachrocks, what makes possible the entrance of coarser sediments in the innershelf

ASSUNTO(S)

coastal dynamic perfil de praia beach profile perfil praial de equilÃbrio coastal protection coastal erosion dinÃmica costeira proteÃÃo costeira oceanografia erosÃo costeira equilibrium beach profile

ACESSO AO ARTIGO

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