Avaliação de técnicas de drenagem urbana sustentável para redução do pico de escoamento superficial em um loteamento no município de Pato Branco - PR

Abstract

The urbanization process has as a consequence the increase of impermeable areas in the cities. This causes changes in the hydrological cycle of the urbanized regions, such as the reduction of infiltration processes, the reduction of the water table supply and the increase of the surface runoff volume. To solve problems arising from the accumulation of water generated on the surface, conventional urban drainage systems were implanted in the cities, which only collect the water and transport it to another point. Thus, this method is not able to mitigate the effects of urbanization in the hydrological cycle, being convenient the use of sustainable drainage systems (SuDS), which have this as one of their goals. The objective of this study was to evaluate the influence of SuDS on the decrease of the surface runoff peak in an urban subdivision. In order to do this, the following specific objectives were established: the first one was to simulate in the EPA SWMM software the conventional drainage project to be implanted, and to compare the runoff with the natural one. The second was to pre-dimension the chosen SuDS devices, detention basins, permeable pavements and bioretention cells, for further insertion into the software. The third specific objective was to simulate the situations with the devices, firstly of each together with the conventional system, and then in combinations. These were: detention basins with permeable pavement, detention basins with bioretention cells, and permeable pavement with bioretention cells, all together with the conventional system. The fourth and last specific objective was to rank the groups of measures for the efficiency of surface runoff control, through tables and graphs obtained through the simulations. Satisfactory results were obtained, since in the three simulated scenarios the peak flow decreased considerably, especially with the combination of detention basin and permeable pavement, that reached a peak 81,5% lower than the conventional system. Furthermore, the volume of surface runoff decreased 71,9% at the combination of permeable pavement and bioretention cells, approaching the pre-urbanization situation. Peak times were delayed, especially the combination of detention basin and bioretention cells that happened 16 minutes later. With this, the efficiency of the alternative systems of urban drainage was verified, as well as the use of the Software as a design tools for these techniques.