This paper presents the numerical modelling of the cross shore propagation of infragravity waves induced by a transient focused short wave group over a sloping bottom. A dataset obtained through new laboratory experiments in the wave flume of the University of Cantabria is used to validate the Reynolds averaged Navier-Stokes type model IH-2VOF. A new boundary condition based on the wave maker movement used in the experiments is implemented in the model. Shoaling and breaking of short waves as well as the enhancement of long waves and the energy transfer to low-frequency motion are well addressed by the model, proving the high accuracy in the reproduction of surf zone hydrodynamics. Under the steep slope regime, a long wave trough is radiated offshore from the breakpoint. Numerical simulations conducted for different bottom slopes and short wave steepness suggest that this low-frequency breakpoint generated wave is controlled by both the bed slope parameter and the Iribarren number. Moreover, the numerical model is used to investigate the influence that a large flat bottom induces on the propagation pattern of long waves.

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In this study, we present a comprehensive map of a microtidal wave-dominated beach system based on an interdisciplinary sea-land approach and with the purpose of supporting a sustainable and successful beach management. The study area is located in a highly urbanized/industrialized coastal sector of the W side of Cagliari Gulf (S Sardinia, W Mediterranean). In the Main Map (1:15,000 scale), static and dynamic features of the beach system and adjacent inner shelf are divided into thematic sections, including geomorphological elements, bathymetry, sedimentological distribution, benthic habitat (mainly Posidonia oceanica meadow), hydrodynamics and anthropogenic features. The map constitutes an example of multidisciplinary benchmark to allow for long-term planning and management of this highly urbanized beach system. It is able to provide a substantial scientific support to policy-makers towards environmental restoration and sustainable development.

Despite the increased sophistication of numerical models and field techniques for investigating wave-induced nearshore sediment transport and ensuing beach morphological response, there remains a significant demand for large-scale laboratory experiments to address this research topic. Here, we describe the Barrier Dynamics II experiment (BARDEX II), which involved placing a near prototype-scale sandy barrier in the middle of the Delta Flume in the Netherlands and subjecting the structure to a range of wave, tide and water level conditions. A unique aspect of the experiment was the presence of a lagoon behind the barrier, as often occurs in natural barrier settings, providing a convenient means to experimentally manipulate the groundwater hydrology within the barrier. The overall aim of the BARDEX II was to collect a large-scale data set of energetic waves acting on a sandy beach/barrier system to improve our quantitative understanding and modelling capability of shallow water sediment transport processes in the inner surf, swash and overwash zone. In this paper we introduce BARDEX II and provide a detailed description of the experiment, including the experimental design, instrumentation, test programme and data set, as well as presenting some examples of the morphological and hydrodynamic data set. We also reflect objectively on the strengths and weaknesses of the data set. This paper serves as an introduction to a special issue of Coastal Engineering, solely devoted to the results of BARDEX II.

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