Tesis doctoral de Amanda Sancho García
The predictability of beach inundation is mainly related to wave runup and most of the formulations that have been developed focus on the hydrodynamics, disregarding the morphological changes caused during storms. For these reasons, the aim of this thesis is to provide more insight into beach inundation processes at embayed and open beaches and to determine how morphological changes can interfere with these processes. To this end, video measurements of beach inundation and the characteristic morphological changes were carried out at two stretches of coast with different wave climates: the stretch comprising la barceloneta, somorrostro and nova icaria, which are three artificial, tideless embayed beaches located in barcelona, spain (nw mediterranean); and noordwijk beach, which is an open, microtidal multibarred beach located in noordwijk, the netherlands (north sea). The effects of a submerged and a detached breakwaters on the morphological and hydrodynamic changes occurring at la barceloneta during storms is examined in chapter 2. The shoreline response before and after the beach nourishment and the construction of the protective structures was compared using a ten-year video-recorded dataset and hydrodynamics modelled using the smc model. As a result of the protection works, la barceloneta was divided into two beaches separated by a salient. A new methodological approach to analyzing beach rotation which eliminates the morphological effect is presented. Results indicate that the beach rotation process has been modified caused by a change in the wave-induced current system from a single dominant alongshore current to one composed of two dominant alongshore currents with opposite directions. In chapter 3, beach inundation affecting the three embayed beaches of barcelona during the 17 strongest storm events of the period 2001-2008 is analyzed using daily time-exposure images. The shoreline variability due to storms was split into beach planform and morphological features in order to determine its influence on beach inundation measurements. The characterization of the inundation depended on the orientation with respect to the wave direction approach and the morphological features. Beach planform changes are the foremost influence on the inundation of barcelona beaches. The inundation at the multibarred beach of noordwijk during the seven strongest storms in the period between 1998 and 2005 is estimated, also using video monitoring techniques in chapter 4. Additionally, the influence of subtidal sandbars on the inundation is analyzed using the xbeach model. To this end, six simulations were carried out using barred profiles measured at noordwijk but differing in sandbar height and location, and one simulation using a synthetic barless profile. Inundation values ranged from 22 to 105 m, with considerable alongshore variation before the peak of each storm because of the presence of the intertidal bars. The mean inundation values along the beach are well estimated using a simple inundation parameter. The xbeach model shows that the inundation is only affected by the morphology close to the shoreline (i.E. By the intertidal bars or the inner bar if it is wide and closer to shoreline). The outer bar does not seem to influence beach inundation prediction at somorrostro beach is evaluated in chapter 5. To this end, inundation measurements using video observations are compared with estimations including the tidal variations and the wave runup formulation of stockdon et. Al (2006) introducing deep water and local wave measurements and computations. The inundation is overestimated if any of the wave heights in the formulation are used. Estimations improved if a local wave height is used, in particular for waves approaching the shore obliquely. Finally, the alongshore variability of the inundation is better captured if the wave runup is assumed proportional to the breaking wave heightbarcelona07
Datos académicos de la tesis doctoral «Beach inundation and morphological changes during storms using video monitoring techniques«
- Título de la tesis: Beach inundation and morphological changes during storms using video monitoring techniques
- Autor: Amanda Sancho García
- Universidad: Politécnica de catalunya
- Fecha de lectura de la tesis: 16/11/2012
Dirección y tribunal
- Director de la tesis
- Jorge Guillén Aranda
- Tribunal
- Presidente del tribunal: alberto Falqués serra
- paolo Ciavola (vocal)
- raúl Medina santamaría (vocal)
- gonzalo Simarro grande (vocal)