Validation of the Flood Maps of Belo Horizonte: Case Study of Ressaca Catchment (PAP014842)

Código

PAP014842

Autores

Rejane Cristina Siqueira Domintos, ILDA MARIA CARVALHO AGUIAR, Nádia I. Melo, Priscilla Macedo Moura

Tema

Flood risk management in mega cities

Resumo

The main Brazilian cities are lately passing through major challenges in urban drainage due to the rapidly and disordered urban growth, that causes major flooding events. In order to diagnose the causes of urban drainage problems and its integration with other urban systems, the Municipality initiates, in 1999, the elaboration of the drainage master plan, which in its first step performed catchments characterization; cadastral survey of the drainage system and creation of a georeferred drainage database. In 2006 the second stage of drainage master plan was initiated, resulting in the hydraulic and hydrological modeling of all channelized streams; identification of the areas potentially susceptible to floods with its association of risk level ? here called Flood Inundation Maps; proposition of a management model for the city and implementation of a hydrological monitoring program. Among the products developed in the second stage of the drainage master plan, we highlight the Flood Inundation Maps and the hydrological monitoring program. The Flood Inundation Maps were developed based on the results of hydrological and hydraulic modeling of the drainage system, in which were identified channels reaches with hydraulic inadequacies, parameterized in terms of probability of occurrences of extreme flows, besides no flow and water level measurements existed. The association between the water levels of flooding and rainfall were performed using equation the IDF (Intensity Duration Frequence) in a Risk Chart. With the hydrological monitoring, program that begins its operation in October 2011, it is possible to validate the Flood Inundation Maps and the Risk Charts. These Risk Charts consists in a graphical tool linking rain heights and duration to a flooding risk level, allowing flood forecasting. It was elaborated for each stream where flood occurrences were identified. The present work concerns the validation the Risk Chart of the Ressaca?s Catchment.