Flooding area simulation through hydraulic modeling in the urban channel: Case study Jatobá stream, in Belo Horizonte, Minas Gerais

Abstract

Due to the absence of efficient drainage systems and high rainfall rates at certain times of the year, flood events in the world and in Brazil, and especially in Belo Horizonte, Minas Gerais, have been observed very frequently. In view of this, this work aimed to develop the hydraulic modeling of an urban canal in order to discuss its drainage cap acity and minimize uncertainties related to water runoff in extreme events.For the maps elaboration and the channel drawing was used the ArcGIS software with its extensions ArcHydro Tools and HEC-GeoRAS. The HEC-RAS software was used to apply the geometric and hydraulic sections data and for hydraulic simulations. As a result of the study, the influence of the Manning coefficient on the flow of a channel was quantitatively verified. Through a set of critical flows, it was also possible to determine the most susceptible to flooding watercourse stretches. In this case, it was observed that the smaller the values of the Manning coefficients of the sections, the higher their critical flow rates, that is, for water bodies piped by coated and finished works, the f low rates needed to flood the sections have higher values high due to the lower friction of the coating material with water flow; whereas, for natural channels, the water volumes per unit of time, which are determinant for the sections flooding, were smallers, precisely because of the greater capacity of the vegetation and soil to resist runoff.