Impacto do volume de sólidos sedimentáveis no escoamento hidráulico e no custo de manutenção de canal de drenagem

Abstract

The Impact of sedimentable solids volume on hydraulic flow and drainage channel maintenance Cost. The study area was the Tamandaré drainage basin, located in the central region of the city of Belém/PA. The research was developed in three stages. Initially, the situation of the Tamandaré Channel was analyzed, investigating the main information related to the management of rainwater in the studied basin, obtaining topographic, hydrological and drainage system data. Then, the main factors and contributors to sediment accumulation in the channel were surveyed. Finally, in the Storm Water Management Model 5.0 software, a simulation was performed with the ideal operation of the drainage channel without the occurrence of solids and precipitation to serve as a parameter for further simulation with the occurrence of solids. The subsequent step simulated scenarios with sedimentation of solids in the macrodrainage structure, considering: a) rainfall, lasting 1.5 h, 3 h, 6 h and 12 h and b) 10%, 20% and 30% of the Channel obstructed by sediments, resulting in 15 hydrodynamic simulations. The last stage of the research presented the Hydrodynamic impacts, demonstrating that the capacity of the Tamandaré channel is sufficient to drain the precipitated volumes with 10% of its volume committed to solids. However, with 20% of the solids occupying the channel bed, flooding occurs in the scenarios of 1.5 h, 3 h, and 6 h of rainfall, only in the 12 h simulation there was no flooding because, with this storm scenario, the precipitation was more distributed, favoring channel flow. The scenario of 30% of the channel occupied with solids resulted in flooding in all precipitation scenarios, the highest flood magnitude occurred during rainfall of 1.5 h reaching 3.44 m, generating a water level of up to 1.07 m above ground on the roads close to the Tamandaré channel. The cost analysis showed that with the current spending scenario it would be possible to keep the Channel free of solids, as long as this cleaning took place on a daily basis in the indicated volumes equivalent to 2 tipper buckets 2 times a day, however, no cleaning in some days such as Sundays and holidays made the accumulation of waste a reality in the canal. Thus, it is necessary to complement the cleaning of the channel for the total removal of the sediments in this drainage channel in the densely occupied urban area of the municipality of Belém.