Simulações de medidas compensatórias sustentáveis de drenagem: propostas em duas microbacias urbanas.

Abstract

The process of occupation and growth of urban centers is usually based on an empirical urban planning, considering the interests of small social groups, and disjointed from other factors that compose a city, such as the hydrographic basin in which the municipality is inserted, the relief, the region's rainfall regime, which interfere with the rainwater drainage system and may present risks to people residing in unduly occupied areas. The disorderly increase of impermeable areas in urban centers causes impacts to the environment and damage to the population, such as floods, if is not done through a planning process. The greater number of impermeable spaces generates high surface runoffs and lead to drainage systems, often inadequate, at their limits of operation. In this sense, the present work sought to apply sustainable low-impact compensatory measures, green roofs, permeable pavements and rain gardens, in two small basins of the city of Campina Grande - PB, in order to mitigate the problems in the urban drainage system of the municipality. The hydrological simulation software used was the SWMM - Storm Water Management Model, with the objective of analyzing the reduction of surface runoff in basins with high and medium risk to floods. The urban drainage compensatory measures were applied in two scenarios: current use observed at the time of the research and with the maximum waterproofing provided in legislation. The results showed a satisfactory performance, with, in some cases, 100% of flor reduction, in the implementation of all the measures, however, the efficiency in the reduction of the volume generated varies according to the areas and criterias` application. The use of the proposed measures is not capable of minimizing all hydrological impacts of urban use and occupation, but the results of this study suggest that sustainable infrastructures should be discussed as a new method of urban flood control, along with the management and control of land use and occupation. It is expected that these results will contribute to future studies, so that the city of Campina Grande, as well as other cities with similar problems, reach an efficient and sustainable level of urban drainage services.