LABORATORY STUDY OF WAVE HYDRODYNAMICS IN THE SURF ZONE IN PRESENCE OF ROUGHNESS

Abstract

In the global context of increasing anthropic pressure on coastal environments, understanding and modelling the physical processes leading to submersion or erosion of the coastline are key factors in anticipating these risks. Many studies of nearshore wave transformation have been conducted mainly on sandy beaches or gentle slopes. On this type of beach, wave transformation models give generally satisfactory results (Thornton and Guza, 1983). Yet, the hydrodynamics of other types of bottoms, specifically rough and/or steep bottoms, are not fully understood and modelled, especially the effect of roughness on frictional dissipation (Péquignet et al, 2011; Monismith et al, 2015; Poate et al, 2018). Thus, a laboratory experiment, in the wave flume (6m long) of Seatech Engineering School, in Toulon, France was conducted both to improve the understanding of physical processes in controlled environment, and to connect the hydrodynamics to the seabed structure.