Variabilidade Morfológica Interanual Da Praia De Boa Viagem, Localizada Na Região Nordeste Do Brasil

Abstract

Boa Viagem and Pina are urban beaches highly economically important both locally and regionally providing protection for the southern coast of Recife, Pernambuco -Brazil. The objective of this paper is to study the interannual morphological changes which occur on these beaches in order to gather information on the erosion processes. For this purpose 6 topographical profiles were monitored, monthly, from August 2002 to December 2005, during spring tide. To establish the position of each profile it was considered whether the beach was protected by reefs, or not, and if there were coastal protection structures. The largest morphological variation was observed in profiles located to the extreme South and North of the area of study (profiles 1 and 5), as well as the profiles located immediately to the North of the coastal protection features (profiles 4A and 4B). Profiles located in the middle of the study area showed stability. As for sedimentary budget the following variations were observed: negative sedimentary budget in profiles P1 (-4 . Profiles 2 and 3 presented a more consistent budget than those of the profiles located at the extremities of the area (profiles 1, 4A, 4B and 5). The profiles did not present morphologic variations in the beach environment like those mentioned in conventional literature. Profiles 2-1, 3-2 e 4A-3 do not present a linear relation between rates of sedimentary budget. However a positive linear relation between profiles 4B-3 and 5-4B was observed. Variations of accretion and erosion found in this study may be related to seasonal variations in the direction of currents along the coast.