Hydrodynamic and Ecological 3D Modeling in Tropical Lakes

Session: 47. - Physical Processes in Lakes

Lais Amorim, universidade de são paulo, [email protected]
Rodolfo Martins, universidade de são paulo, [email protected]
Brigitte Vinçon-Leite, École des Ponts ParisTech, [email protected]

Abstract

Vertical stratification affects all physical, chemical and biological processes. This phenomenon leads to a segregation in water column, what changes the dissolved oxygen profile, the lake nutrients enrichment, and can cause an algal bloom, what compromise the water quality. Tropical lakes suffer the effects of hydrodynamic behavior more intensively than others, once that they commonly stratify and mix during the day (Huang, 2010; Medrano et al., 2013; Kirillin and Shatwell, 2016). The goal of this paper was to use a numerical model, Delft-3D, to understand and demonstrate lakes hydrodynamic circulation and ecological behavior, and provide better information to reservoir management. The model was implemented for two different lakes (shallow and deep), located in São Paulo – BR, the input data of the model was produced by a high frequency monitoring. Hydrodynamic and ecological cycle of both lakes was very well represented in the 3D model, with Nash-Sutcliffe coefficients about 0.4 in calibration and validation. The model results analysis shows that the process of vertical stratification and mixing is mandatory on the nutrients availability in the water column, and so in the algal bloom. Development in forecasts of that blooming can avoid losing in water supplies systems and health’s damages.Vertical stratification

1. Keyword
harmful algal blooms

2. Keyword
hydrodynamic model

3. Keyword
lake model

4. Additional Keyword
tropical lakes

5. Additional Keyword
delft 3D

6. Additional Keyword
shallow lakes