AVALIAÇÃO DO DESEMPENHO DE UM MODELO CHUVA-VAZÃO EM RELAÇÃO A DISCRETIZAÇÃO ESPACIAL DA BACIA DO RIO ITAJAÍ DO SUL

Código

END137

Autores

Bruno Henrique Abatti, Gabriele Vanessa Tschöke

Tema

1 - Previsão e mapeamento de inundações

Resumo

As the magnitude and frequency of extreme hydrological events increase, studies seek to understand the triggering processes of these events. Regarding flood mechanisms, hydrological models are one of the most used tools to understand it's processes dynamics. In this context, the Hydrologic Modeling System (HEC-HMS) was applied in Itajaí do Sul river basin to verify the effectiveness of these tools. Considering the model's limitations, we evaluated the impact of spatial discretization of the basin on the performance of rainfall-runoff model. The model showed difficulty to represent certain events when the entire basin was discretized as a single unit with homogeneous characteristics. The Nash-Sutcliffe coefficient (Cns) for calibration was 0.718 and 0.333 for validation. Conversely, when the basin was discretized in 7 sub-basins, the obtained results were more consistent, having a calibration Cns of 0.944 and validation Cns of 0.634. Thus, the level of spatial discretization of the Itajaí do Sul river basin is determinant in the model's performance.