Wave energy distribution at inlet channel margins as a function of ebb tidal delta morphology: Cananéia Inlet, São Paulo, Brazil

Abstract

Wave energy gradients between and along the margins of inlet channels play an important role in defi ning the inlet margins' evolutionary processes, mainly those related to spit erosion or accretion, and inlet migration. The aim of this study is to understand the wave power distribution along the margins of a tidal inlet (Cananéia inlet, São Paulo, Brazil), its variation over time, and the infl uences of the ebb tidal delta morphology on the incoming waves. To evaluate changes in bathymetry and morphology of submersed features, we apply geoprocessing techniques to analyze nautical charts from the Brazilian Navy from 1939, 1971, 1985 and 2004. The numerical model MIKE21 SW was applied to assess wave propagation and nearshore wave power. Hence, wave energy levels along the inlet margins were assessed in terms of decadal morphological changes. The results indicate a dynamic behavior of the inlet and ebb tidal delta, pointing to the ebb tidal delta as the main transforming agent of the waves that reach the inner portion of the channel. The morphological changes of the ebb tidal delta over the last decades are critical to defi ne the action of waves on the margins of the inlet.

Wave climate and power distribution around a rocky island: Alcatrazes, Brazil

“…In order to decrease the computational modeling effort, the grid has cells of 500 x 500 m in areas far from the archipelago, and in the region of interest, maximum refinement, reducing the size of the cells to 55 x 55 m. Four open boundaries have been used (northeast, southeast, southwest and northwest), where the most frequent wave events were included as initial condition for the simulation. This wave scenarios refer to cases with frequency of occurrence equal or greater than 5% according to the direction and significant wave height and the most frequent peak period associated, as applied by other studies (e.g., Ambrosio et al, 2020;Lavenère-Wanderley & Siegle, 2019;Siegle & Costa, 2017;Silva et al, 2016). Thus, here we consider 43 cases defined after analyzing the general climatology of the waves (7 for the interannual period, 7 for autumn, 9 for summer, and 8 for spring and 8 for winter) and 4 cases for the analysis of extreme events.…”

Tidal inlet migration and formation: the case of the Ararapira inlet - Brazil

“…The precipitation regime presents an annual mean of around 2500 mm. The prevailing wave direction, with higher sediment transport capacity, varies between S, SSE and SE quadrants (Portobrás, 1983;Pianca et al, 2010;Nemes and Marone, 2013;Silva et al, 2016;Ambrosio et al, 2020), with dominant wave height being 1.5 m and period of 8 s (Silva et al, 2016). Waves generated longshore drift in the region presents a net northwards drift.…”

Active mechanisms controlling morphodynamics of a coastal barrier: Ilha Comprida, Brazil

“…During the fall and winter seasons, the passage of cold fronts, associated to a higher frequency of cyclogenesis, intensifies winds, which is reflected in the higher frequency of high wave energy events (Nimer, 1989;Pianca et al, 2010). In the Southeastern sector, waves from the South and the East were dominant in all seasons (Ambrosio et al, 2020;Pianca et al, 2010) with different contributions, due to the synergy of waves (Pianca et al, 2010). This configuration generates a seasonal pattern of longshore transport (Silva et al 2016).…”

“…This configuration generates a seasonal pattern of longshore transport (Silva et al 2016). Wave energy gradients affected the evolutionary processes of the inlets, mainly of those related to spit erosion or accretion and to inlet migration (Ambrosio 2020).…”