Sand transport in active and hunged coastal dunes of southeastern Buenos Aires

Abstract

The sand transport by wind is the main sediment source of supply of silts for the presence of coast dunes in sandy beaches, as well as an important component in the calculations of sedimentary balance among the beach (the source) and the dune (the destination). To evaluate this action, dunes of the southeast of Buenos Aires province were analyzed by means of a new sampling method that allows to see differences in the dynamics and texture of the sand that conform the profile of speed, differences due to its genesis and characteristic. The objective of the work was to analyze if there were quantifiable appreciable differences in the characteristics of coastal dunes hung in cliffs of Mar del Plata and in front dunes, of open costs to the south of the same area, in the La Ballenera creek. It was observed that the sands of frontal dunes are coarser than those of the hunging dunes, due to the contribution areas and topographical location. The biggest transported volumes of sand are for the windward face and crest. The profile of the La Ballenera creek is more influenced by the marine effect that the hunging dune, where the eolic action prevails. It was observed that when the speed of the wind is duplicated, the ported volume was 5 larger more, the same thing that the t_o. The drag coefficient went practically worthless to 2,6 m. The methodology used to trap the silt turned out to be acceptable as an initial phase for the monitoring of the dynamics of coastal sectors dominated by the wind.