Using the average directions of the main wave-fronts which approach the coast of Bahia State -coinciding with that of the main wind occurring in the area -and of their periods, we define a wave climate model based on the construction of refraction diagrams. The resulting model of sediment transport was able to reproduce, in a general way, the sediment dispersion patterns furnished by geomorphic indicators of the littoral drift. These dispersion patterns control the generation of different types of sediment accumulations and of coastal stretches under erosion. We demonstrate that the presence of the Abrolhos and Corumbaú Point coral reefs is an important factor controlling the sediment dispersion patterns, since them act as a large protection against the waves action. key words: Littoral drift, wave refraction, numerical modelling, State of Bahia, Brazil.
The Sã o Francisco River mouth is undergoing a severe erosional process that has caused the destruction of a village and the partial immersion of a lighthouse constructed in 1856. The present work comprises an historic time evaluation of this phenomenon based on the analysis of the sediment dispersion patterns caused by waves along three distinct shoreline traces. For this, we define a wave climate model based on the construction of refraction diagrams, which are assumed to be valid for the three shorelines. The resulting sediment transport patterns obtained by numerical modeling from the refraction diagrams-taking into account the angle of approach and the wave height along the coast-allow us to establish a first-order correlation between coastal dynamics and erosion phenomenon. The results also suggest that a permanent reduction in the solid river discharge, in response to the construction of large dams, probably will have two direct consequences in the river mouth region: (i) a chronic shoreline erosion downdrift of the mouth and (ii) a progressive deflection of the mouth in the downdrift direction.
Urban areas are hotspots for marine litter. Plastic materials are the most common type of beach litter and can fragment into even smaller pieces. A total of 24 sampling stations were distributed along the coast of Salvador, Brazil, from which every litter item > 2 cm was sampled. A total of 17,089 items were sampled from the beaches of Salvador in two different survey seasons (10,416 during the winter and 6,673 during the summer). Plastic represented 87.45% of all materials sampled during the winter and 85.24%, during the summer. In both seasons, the majority of the sampled beaches were classified as extremely dirty according to the Clean-Coast Index. Plastic fragments were found in every sampling station in both field surveys, representing 45.7% of the overall plastic items sampled. Tourism/recreation activities appeared to be important sources of litter to the area. Keywords: plastic pollution; plastic fragments; coastal management; urban beaches; coastal currents. 16 OCT 2015; Peer review: 12 NOV 2015; Revised: 18 NOV 2015; Accepted: 24 NOV 2015; Available on-line: 26 NOV 2015 This article contains supporting information online at http://www.aprh.pt/rgci/pdf/rgci-649_Fernandino_Supporting-Information.pdf Fernandino et al. (2016)
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