Experimental study of runup for sandy beaches under waves and tide

This paper describes an experimental investigation of runup for intermediate sandy beaches from a physical modelling in a wave flume with tide simulation. Shoreline elevation measurements are acquired over a wide range of conditions using an optical method. Simultaneous morphological and hydrodynamic changes are considered to determine the best parameters to predict the maximum wave runup. The tidal level significantly affects the breaking conditions (position, height and type), and the slopes of the beach. Present data show that the surf zone slope and the wave breaking height should be used to estimate the maximum runup. The results are compared with previous formulations issued from the literature. A new formula is proposed for the runup estimation for intermediate beaches. •Laboratory study of intermediate beaches in a wave flume with tide simulation.•Processes governing beach profile changes during a tidal cycle.•Parametric study of runup: breaking conditions and beach slopes are tested.•New formula of runup based on surf slope and wave breaking height.•Comparison between present experimental results and runup prediction formulae.