EROSIVE AND ACCRETIVE MOBILE BED EXPERIMENTS IN LARGE SCALE TESTS

摘要

Traditionally data and analysis for erosive or Accretive wave conditions have been carried out at relatively small scales and without enough spatial coverage or resolution. This limits the in depth analysis and does not allow an undistorted (with respect to NATURE) and reliable analysis. In this paper we shall present a sample of 1 Erosive and 2 different Accretive wave sequences acting on a large scale beach profile experiment carried out at the CIEM wave flume in Barcelona. The experimental intervals are large enough to properly assess the impulsive response to large wave events and the underlying trends. We shall be looking at collocated hydro and morphodynamic time series with emphasis on the time scale of the drivers and responses. The subsequent analysis will deal with the different net transport rates between both Accretive conditions and within the different Accretion pattern of both tested conditions. We shall examine the velocity and acceleration skewness of the measured time series at two different points along the bar, while the net transport of the bar decrease with the adaptation of the profile to a more stable situation. The resulting beach behavior will be discussed as a function of the driving hydrodynamics and original beach settings.