Drenagem urbana sustentável: avaliação do emprego de técnicas compensatórias em bacia urbanizada.

Abstract

Population growth in recent decades has resulted in the increase of urbanization processes in a disorderly way, accentuating the occurrence of problems related to water infrastructures in the urban environment, such as floods. Through hydrological modeling, it is possible to analyze compensatory techniques in order to control the adverse effects arising from urban surface runoff and thus readjust or increase the hydraulic efficiency of drainage systems. This work aimed to evaluate the impact of the implementation of compensatory techniques in urban drainage applied to an urbanized hydrographic sub-basin through a calibrated and validated model. The areas susceptible to the generation, transport and accumulation of surface runoff were identified, and the compensatory techniques to be installed in these areas were determined according to the individual characteristics of each one of them. Using the Storm Water Management Model (SWMM)¸ simulations were performed with different occupation scenarios and the use of compensatory techniques (source and centralized control). Based on the results, the ability to control flood peaks and surface runoff was observed due to the implementation of compensatory techniques by increasing the storage capacity and water infiltration. Centralized control proved to be more efficient, through the implementation of detention basins, with reductions from 77.81 to 97.77% in peak flows in each of the evaluated scenarios, followed by source control through micro- reservoirs with 44 .62% to 69.09% and then by the vegetated roofs with 18.71% to 40.53%. In addition, it was found that the measure of planting native vegetation was not effective in the analyzes carried out, not being indicated as a way of mitigating the problem of flooding in the hydrographic sub-basin.