Utilização do software SWMM na modelagem hidrológica da sub-bacia do ribeirão Vai e Volta – Poços de Caldas/MG

Abstract

As a result of the urbanization process, the waterproofing of areas contributes to the aggravation of flooding and inudation in urban areas through the increase of flows and drained volumes, causing socio-environmental problems in urban watersheds. In order to study the behavior of urban drainage related to precipitation events, hydrological models are used within the watershed. Thus, the present work aims to apply the SWMM model in the sub-watershed of the Vai e Volta stream, located in the city of Poços de Caldas-MG, in order to portray the hydrological behavior of the urban watershed and contribute to decision-making tool in management and rainwater management in the city. The characterization of the watershed under study, the fluvio-pluviometric monitoring, as well as the sensitivity analysis and manual calibration of the rain-flow model were performed using the Storm Water Management Model - SWMM software. It was observed that the most sensitive parameters to the model are: the impermeable area of the sub-areas (AI), the roughness coefficient relative to the portions of the impermeable sub-areas (n-imperv), the width of the sub-areas (W) and, to a lesser extent, the slope of the sub-areas (S). In the calibration and model validation processes the results obtained related to the mean Nash-Sutcliffe (NSE) coefficients are 0.73 and 0.79, respectively, and errors in peak flow and mean flow are less than 15%. The results show a satisfactory performance of the SWMM hydrological model in the representation of the Vai and Volta stream subwatershed. It is expected through hydrological modeling to contribute to the development of studies on sustainable urban drainage.