Data: 17/09/2014 à 19/09/2014
Local: São Paulo - Brazil
Containment Analysis of Microdrainage to Avoid Flooding of St. Peter Stream in the Urban Area of Uberlândia - Mg (PAP014768)
Luciana Alves Sá, Ana Clara Mendes Caixeta, Carlos Eugenio Pereira
The significant growth of cities caused an inadequate land use, creating an interaction between population and water esources, consequently causing an environmental imbalance. These drainage changes includes waterways modifications and the construction of drainage galleries. In cities, these galleries can be divided into macrodrainage of main channels and microdrainage characterized by stormwater in secondary pathways. In addition, microdrainage, which feeds macrodrainage, can be quantified mainly by impervious surfaces and increased runoff, directly affecting the flow of flood peak. This growth increases overflow events, resulting in catastrophic consequences such as social, economic and environmental damage situations. Given this, urban drainage planning is necessary to preserve the macro and microdrainage, reducing floods and seeking to improve the population's quality of life. Thus, the main objective of this work is to evaluate the modification of microdrainage by urban occupation in order to determine a tolerable flow launched at Rondon Pacheco Avenue, in Uberlândia - MG. The methodology first used in this study was the bibliographic review in the differentiation of micro and macro drainage. Afterwards, analysis of the streets' designs, levels of field curves and the rain galleries layouts, for the area's acknowledgment, followed by the basin's characterization, with permeable and impermeable areas. Thus, the mapping of land use in the basin using satellite imagery and field investigation was conducted. To determine the maximum rainfall intensities, the project flow, rational method was used, considering that the basin has less than 2 ha of used area. For microdrainage sizing, it's used the expression Strickler-Manning, to calculate the speed on the gutter ,allowing the microdrainage flow calculation by the continuity equation. To estimate the capacity of exhausting inlets, these are considered free spillway sill (TUCCI, 2009). In this work, we adopted an increase coefficient of 20%, due to runoff obstructions on the waterways, such as waste and ramps. Furthermore, we analyze the characteristics of Rondon Pacheco Avenue, which has the closed conduit Stream St. Peter, to determine the flow capacity of this channel. So ,after the studies, it was found that this avenue has experienced a significant occupation after 1980, that modified areas of permeable to impermeable, and generating increased runoff and reduced infiltration. In addition, analyzing historical floods, several alarming situations occurred, which generated a change in infrastructure channeling rain water system next to the channel. However, during the great flood in 2013, channeling macrodrainage didn't obtain a full section (maximum ¾ section), confirming the need of studies on microdrainage. The basin of the São Pedro stream has approximately 7% of its occupancy area free, but this area is already within the city limits and urban growth vectors, such as a mall under construction.