Desenvolvimento Experimental de uma Estratégia de Controle Morfodinâmico de Perfil de Praia Arenosa Dominada por Ondas

Abstract

Coastal engineering strategies to adapt population and their socioeconomic activities around the oceans is a theme that is constantly present in the history of civilization. One of the main current challenges is to contain erosive processes on the shore, where many cities are feeling the effects of the coastline retreat. For this reason, the needs of modern society must be included in coastal engineering projects, which should be developed taking into account the natural concepts of the dynamics of each system. This is the motivation of the present study, which aims to demonstrate that a sandy profile that is vulnerable to erosive processes can be managed to become a predominantly dissipative profile, by introducing a sandy bank able to induce wave breaking. For this strategy, concepts of transverse morphodynamics of sandy beaches and of submerged porous coastal structures were used. When the structure was placed in the location of the anti-node of the system`s longitudinal hydrodynamic oscillation within a wave channel, it was possible to control the transport of sediments. The strategy was to accumulate the sediments inside the porous structure to replicate the shape of a distal sandy bank, which started to induce waves’ breaking. In turn, a wide and turbulent breaking zone was generated able to dissipate more energy than the ‘natural’ breaking zone. A dissipative morphodynamic system was predominant during the high and low wave energy scenarios. The strategy of using a submersible structure with high porosity has the advantage of being integrated in the natural morphodynamic processes. In addition, this is a lightweight structure compared to the traditional coastal engineering solutions, and it can be economically more attractive.