Using Wind Direction and Shoreline Morphology to Model Sand Dune Mobilization

Abstract

Carvalho, A.M.C.; Ellis, J.T.; Lamothe, M., and Maia, L.P., 0000. Using wind direction and shoreline morphology to model sand dune mobilization. Journal of Coastal Research, 00(0), 000-000. Coconut Creek (Florida), ISSN 0749-0208. This paper aims to establish a relationship between wind direction, shoreline position, and aeolian transport directions. We use Ceará State in NE Brazil, which mainly comprises barchans, barchanoids, parabolic dunes, and large flattened composed dunes to formulate and test a dune transport model that can be applied to north and east facing beaches. The headland-bay beaches of Ceará progressively increase in angle from E to W. This is accompanied by a corresponding change in the near-beach dune migration direction. A significant change in the wind pattern for the northern portion of Ceará was found, which resulted in a shift in dune migration from E-W to ENE-WSW as the shoreline orientation changed from NW-SE to W-E. The different aeolian transport conditions along the stretches of the headland-bay beach gradually shifted from transport parallel to the shoreline to unimpeded aeolian transport that moves sediments inland. Beach feeding occurs from headland bypass as dunes occupy the area landward of the headland. A zone of composite wind transport directions, winds carrying sand directly from the beach and those transporting sediment landward of the headland, was identified. This variation of wind transport conditions is confirmed by the dune morphology and influenced by the relationship between shoreline position and wind angle approach. The proposed model uses the sine of the angle between wind direction and shoreline orientation to predict aeolian transport and determines the volume of sediment transported by the wind. This model identifies stretches of shoreline under different aeolian transport directions and exhibits compatibility with measured dune migration.

Should Anthropic Ridges Framed as Foredunes Be Considered Real Dunes?

“…In this segment, there is intense feedback on the beach from the sediments transported by the wind from the upstream-facing of the promontory into this area. In the second segment, which presents a straighter coastline than the segment above, the wave refraction process predominates, with a tendency to hit perpendicular to the coastline, minimizing drift transport in taking more sediment available for wind transport towards the interior of the continent [51,56] (Figure 2). There is a relationship between winds and shoreline orientation for the coast in southern Brazil, wherein the foredune volume is at a minimum in the greatest bay curvature of the beach and at a maximum in the smoothing curvature stretch of the coast [57].…”

geomorfologia costeira e seu desdobramento para a geografia costeira e marinha

“…2003) analisa a velocidade do vento e o transporte de areia numa duna barcana, e Carvalho (CARVALHO et al 2004) relaciona a deriva litorânea ao potencial de formação de dunas, enquanto Maia (MAIA et al 2005) relaciona o incremento de transporte eólico e de migração de dunas ao efeito El Niño, Meireles (2011) analisa a velocidade de migração de dunas móveis de Jericoacoara, e Castro (2005) relata o soterramento devido à migração de uma duna transversal em Paracuru. Em outro trabalho, Alexandre M. Carvalho (CARVALHO et al 2016), analisa a relação entre a direção do vento, e a linha de costa, na mobilização de dunas de areia em dois segmentos de orientação distinta do litoral cearense. Uma análise faciológica e estrutural dos depósitos eólicos costeiros do oeste do Ceará foi realizada por Mesquita (MESQUITA et al 2016…”

On Odour Emission Rate From the Working Area of a Municipal Solid Waste Landfill in China

“…Besides the properties of MSW, the amount of odour diffusion from the landfill surface source is affected by the meteorological conditions (Chiriac et al 2009, Dincer et al 2006. Most previous studies were based on the sampling method of instantaneous ambient air or using short-term enrichment tubes, from which the odour concentration tested is heavily influenced by the meteorological condition, and the quantity of odour diffusion from the landfill surface source is difficult to generalize or deduce (Grzeczka and Szymak 2016, Carvalho et al 2016, Qu et al 2017. Some previous studies determined the downwind odour concentration and used the concentration data to calculate the diffusion with a Gaussian diffusion model (Chemel et al, 2012;Nicolas et al, 2006); however, the heavy field test workload and the stability of the meteorological conditions during the testing can substantially influence the test results (Chemel et al 2012, Nicolas et al 2006, Xiao et al 2017.…”