Numerical and remote techniques for operational beach management under storm group forcing

Abstract

Abstract. The morphodynamic response of a microtidal beach under a storm group is analyzed, and the effects of each individual event inferred from a numerical model, in situ measurements and video imaging. The first storm, with moderate conditions (H s ∼ 1 m during 6 hours), eroded the aerial beach and generated a submerged sandbar in the breaking zone. The bar is further directed offshore during the more energetic second event (H s = 3.5 m and 53 hours). The third storm, similar to the first one, hardly affected the beach morphology, which stresses the importance of the beach configuration previous to a storm. The 5 volume of sand mobilized during the storm group was around 17.65 m 3 /m. During the following months, which were characterized by mild wave conditions, the dry beach recovered half of the volume of sand that was transported offshore during the storm group (∼ 9.27 m 3 /m). The analysis of beach evolution shows two different characteristic time scales for the erosion and the recovery processes associated with storm and mild conditions respectively. Besides, the response depends largely on the previous beach morphological state. The work also stresses the importance of using different tools (video-monitoring, 10 modeling and field campaign) to analyze beach morphodynamics.Copyright statement.

Coastal Impacts Driven by Sea-Level Rise in Cartagena de Indias

“…Video monitoring systems developed after the apparition of digital cameras, have shown to be a powerful and low-cost tool to monitor the coast in a wide range of studies, such as, coastal variability (Nieto et al, 2010;Simarro et al, 2015), intertidal bathymetry (Aarninkhof et al, 2003) or evolution of beach systems (Ojeda and Guillén, 2008). Since video systems have the advantage of providing continuous monitoring of coastal areas they are also a valuable tool to validate numerical models (Salmon et al, 2007;Andrade et al, 2013;Morales-Márquez et al, 2018;Osorio et al, 2019). In this work, we have used video images from the HORUS monitoring system 3 at Bocagrande, to validate the run-up provided by SWASH model.…”