Viabilidade hidro-sedimentológica de um canal de maré projetado no oeste da Lagoa de Araruama - RJ

Rodrigo Silva,Paulo Rosman

doi:10.21168/rbrh.v21n1.p25-35

Abstract

The Araruama Lagoon, Brazil’s largest hypersaline lagoon, is an important estuarine system located in the southeast of the state of Rio de Janeiro. This lagoon is oblong-shaped and extends for circa 40 km from west to east at its longest axis. Since it has a negative water balance and only one connection with the open sea, through the long Itajuru Channel, there is very little water renewal, which causes a natural tendency to eutrophication. Creating a new maritime connection on the western side of the Lagoon would take advantage of the very frequent ENE winds, generating a drift from east to west that would increase water renewal and, consequently, enhance the quality of the environment. This paper analyses the hydro-sedimentological viability of this tidal inlet using computer models. Initially the sizing of a stable inlet is discussed considering an analysis based on well established criteria of stability of tidal inlets and with 1D computational modeling. Afterward, through 2DH hydro-sedimentological modeling, the morphodynamic evolution of the lagoon, its tidal inlets and adjacent maritime region, are analyzed considering the projected situation. The inlet considered changed very little in the lagoon’s bathymetry and remained unobstructed during the 365 days of simulation.

Highlights

The Araruama Lagoon, Brazil’s largest hypersaline lagoon, is an important estuarine system located in the southeast of the state of Rio de Janeiro
O modelo simulou várias vezes o escoamento na Lagoa, com as áreas das seções hidráulicas do Canal Oeste variando de 40 a 2000 m2, e amplitudes de maré variando entre 0,10 m e 0,70 m
A próxima etapa desta pesquisa contemplará o estudo dos processos litorâneos que ocorrem na região da embocadura marítima do Canal Oeste, bem como uma simulação de sua evolução morfológica, considerando o transporte de sedimentos gerado por ondas que incidem na costa

Summary

Introduction

The Araruama Lagoon, Brazil’s largest hypersaline lagoon, is an important estuarine system located in the southeast of the state of Rio de Janeiro. O local escolhido, mostrado na figura 2, é aquele que promoveria o melhor resultado em termos de renovação de águas, uma vez que os ventos dominantes da região, vindos de Figura 1 - Lagoa de Araruama com canal de maré em seu extremo oeste.

Results

Conclusion