Fully coupled hydrological–hydrodynamic modeling of a basin–river–lake transboundary system in Southern South America

Abstract

The Mirim and Patos Lagoons form the largest lagoon complex in South America. Wind is one of the dominant climatic elements of circulation and water levels in the basin. Therefore, we aimed to better understand the effects of wind on the Mirim–São Gonçalo watershed by applying the MGB hydrological model and to assess whether it would produce satisfactory results for modeling. Various tests were performed to determine the best representation of the processes involved and the observed levels. The best results were obtained with the inclusion of sub-daily wind data in the simulation and also the downstream boundary condition by using the observed water level data at the sluice dam of the São Gonçalo channel. The results showed that the model could successfully simulate the levels and demonstrated the importance of including the wind when modeling the hydrodynamic processes of large lake environments.

Influence of Multiple Water Uses on an Important Cross-border Watershed in South America

“…This study considered the parameter value of 100 m because it was introduced as the most suitable one to the study area in the model proposed by Possa et al (2022).…”

Hydrological-hydrodynamic simulation and analysis of the possible influence of the wind in the extraordinary flood of 1941 in Porto Alegre

“…This model was chosen for this study due to (i) its good performance in simulating South American basins, including the Patos Lagoon basin itself [e.g., Paiva et al (2011)]; Siqueira et al, 2018;Lopes et al, 2018); (ii) it uses an integrated coupling approach between the hydrological-hydraulic and hydrodynamic models, allowing the representation of backwater effects and the simulation of flat complex basins (Possa et al, 2022); (iii) its use of a simple pseudo-two-dimensional approach that allows complete coupling between simulation models (Pontes et al, 2017) and; (iv) it allows to represent the influence of wind shear on shallow bodies, having been successfully tested by Lopes et al (2018). Despite MGB's many advantages, the model also has limitations for application in some basin systems but that, for its use in the present study, do not apply or are not relevant.…”

“…The MGB model has a hydrodynamic calculation methodology for flow propagation in the hydrographic network that solves the Saint-Venant equations expressed by the continuity equations (Equation 1) and momentum conservation (Equation 2) in an almost complete manner, ignoring only the advection, the second term in Equation 2, called inertial method (Bates et al, 2010). It is nonetheless able to represent backwater effects, floodplain attenuation, rivers with low slopes (Pontes et al, 2017;Fleischmann et al, 2018;Possa et al, 2022), or even zero slope, such as the Guaíba River, and other that drain into the Lagos system of the Patos Lagoon basin.…”

“…Recently, the MGB model was also improved to allow the representation of the wind shear effect on large water surfaces, having been tested in the Patos Lagoon by Lopes et al (2018). This improved version of the model was also used by Vanelli et al (2020) in the Tubarão River Basin/SC and Possa et al (2022) in the Mirim-São Gonçalo.…”

“…We evaluated six values for d C at this stage, all of them within the range mentioned in the literature for the region (Paz et al, 2005;Cavalcante & Mendes, 2014;Lopes et al, 2018;Possa et al, 2022):…”