Tendência de longo prazo à erosão costeira num cenário perspectivo de ocupação humana: litoral norte do estado da Bahia

Abstract

Revista Brasileira de GeociênciasAbílio Carlos da Silva Pinto Bittencourt et al. 40(1): 125-137, março de 2010 Arquivo digital disponível on-line no site www.sbgeo.org.br 125Tendência de longo prazo à erosão costeira num cenário perspectivo de ocupação humana: litoral norte do estado da Bahia Abstract Long term coastal erosion trend in a perspective scenery of human occupation: northern coastline of the Bahia State.In this work, based on a numerical wave-motion simulation, we define the estimated pattern of sediment dispersions caused by waves along the northern coastline of Bahia state. For such modeling, we have considered both the angle of approach and the wave height along the 10m isobath, within a wave climate model based on the construction of wave-refraction diagrams, as a function of the current boundary conditions. Two unidirectional systems of opposite directions were identified for the net drift of coastal sands, what is supported by geomorphic drift indicators. The nodal divergence point of these systems is located in Baixio. This divergence implies a continuous retirement of sediment in its neighbouring, and explain the present erosion observed in the area. It also explain why the Quaternary deposits are practically absent there, pointing out to a local long term trend of sediment deficit. Thus, this divergence zone weaken the associated coastal stretch favoring the waves attack. In addition, it is suggested that the strong winds following cold fronts along the coast can generate meteorological tides, contributing, in conjunction with the proximity of equinoctial spring tides, for a more effective wave attack of the coastline. It is under this scenery, where it can not be discarded the permanence of this vulnerability to erosion, that is being developed a planned application of large investments in construction of touristic and residential equipments.

Composition and diversity of anurans in the Restinga of the Conde municipality, northern coast of the state of Bahia, northeastern Brazil

“…The sampled area studied herein was positioned alongside the coastline on areas of Holocene and Pleistocene deposits known as marine terraces (see Dominguez et al 1999, Esquivel 2006, Nogueira 2006and Bittencourt 2010 for geological-geomorphological descriptions and maps). Wetlands of a mosaic of shapes and sizes occur in the lowlands between these deposits, also present in the inland valleys associated with the Barreiras Formation of Tertiary age (Coastal Tablelands).…”

Caracterização Das Planícies De Marés Do Litoral Centro - Sul De Sergipe a Partir Das Séries Ambientais Geomorfológicas

“…O sentido da deriva litorânea efetiva no litoral sergipano contribui para a morfodinâmica das desembocaduras e na intensificação dos processos oceanográficos. De acordo com Bittencourt et al (2010), o sentido da deriva efetiva no litoral sergipano é de NE/SW, com mudança no sentido na desembocadura dos rios Piauí/Real, que é de SW/NE, corroborado pela presença de um indicador geomórfico: o pontal arenoso na desembocadura do rio Real (Figura 4).…”

Edição completa

“…gov.br). O sentido da deriva litorânea efetiva foi extraído das análises realizadas por Bittencourt et al (2005) e Bittencourt et al (2010).…”