This paper presents a numerical modeling estimation of the sediment dispersion patterns caused by waves inciding through four distinct coastline contours of the delta plain of the Doce River during the Late Holocene. For this, a wave climate model based on the construction of wave refraction diagrams, as a function of current boundary conditions, was defi ned and was assumed to be valid for the four coastlines. The numerical modeling was carried out on basis of the refraction diagrams, taking into account the angle of approximation and the wave height along the coastline. The results are shown to be comparable with existing data regarding the directions of net longshore drift of sediments estimated from the integration of sediment cores, interpretation of aerial photographs and C 14 datings. This fact apparently suggests that, on average, current boundary conditions appear to have remained with the same general characteristics since 5600 cal yr BP to the present. The used approach may prove useful to evaluate the sediment dispersion patterns during the Late Holocene in the Brazilian east-northeast coastal region.
PATTERNS OF SEDIMENT DISPERSION ALONG THE DISCOVERY COAST (BRAZIL) The patterns of sediment dispersion along the Discovery Coast (Brazil) is characterized by three sediment longshore transport divergent zones. The divergent zones were defined through analysis of the wave climate along with wave refraction diagrams and the establishment of a sediment dispersion model. In the study area the sediment dispersion and the associated divergent zones are mainly controlled by coral reefs located along the coast, forming a barrier to the stronger SE and SSE waves. This causes, in some coastal segments, an inversion in the sediment drift direction, due to the dominance of the weaker E and NE waves.
By using the mean directions of the wave-fronts approaching the Brazilian northeastern coastal stretch comprised between the localities of Real river (Sergipe State) and Galinhos (Rio Grande do Norte State) -coincident with those of the main winds occurring in the area -and their periods, we have defined a wave climate model based on the construction of refraction diagrams. The resulting model of sediment transport, as obtained by numerical modelling from the refraction diagrams, taking into consideration the angle of approach and waves heights along the 10-m isobath, was capable of reproducing the patterns of sediment dispersion provided by geomorphic indicators of the longshore drift. All this coastal region, approximately 900 km in length, is characterized by a significant divergence zone in the direction of net longshore drift of sediments, the potential intensity of which increases considerably in value, in almost its entire length, continuously toward downdrift, which might explain the greater or lesser long term susceptibility to erosion, during the Quaternary, along the coastal stretch studied.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.