Hydrodynamic simulation of the impact of flood events in urban drainage channel caused by coincidence of rainfall and tidal oscillations. The study area was Tamandaré drainage basin, located in the central region of the city of Belém / PA. The research was developed in three stages. Initially, the main information related to the management of rainwater in the basin was investigated, obtaining topography, hydrological data and the drainage system. Then, in the SWMM 5.0 software, 14 simulations of runoff scenarios were carried out in the macrodrainage structure, considering: a) rainfall, lasting 1.5 h, 3 h, 6 h and 12 h; b) tide, high and low tide conditions; and c) rainfall + tide. Finally, new simulations were performed with the use of floodgate in the scenarios that presented floods. With the research, it was verified that the contribution area of the Tamandaré basin is smaller than the one presented in official sources, as well as intense rainfall, high tidal levels and flooding of roads. With the results of the simulations, it was verified that the capacity of the Tamandaré channel is sufficient to leak the precipitated volumes and low tide volumes separately. However, when the high tide is above 3.39 m flood occurs, situation aggravated in coincidence with rainfall. The highest flood magnitude occurred during rain of 6 h and high tide reaching 3.44m, generating a water level up to 1.07 m above the ground in the roads near the Tamandaré channel. In spite of the use of the dam, flood events were also observed, with the worst situation occurring during 12 h rain and high tide, forming a water level of up to 0.69 m above the ground. Therefore, the floodgate application must be complemented by other technical devices for containment and / or pumping the surplus volume of rainwater, to avoid the occurrence of floods in the coincidence of intense rainfall and high tide events in this drainage channel of the densely occupied urban area of the municipality of Belém.
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