Avaliação experimental de superfícies na redução do escoamento superficial direto

Abstract

This work aimed to evaluate and compare the efficiency of five different coatings used in urban areas: lawn soil, bare soil, waterproof concrete lining, hollow concrete blocks and solid concrete blocks used to reduce runoff. The research was based in experimental tests, conducted in portions constructed in triplicate to each type of surface, under which they were realized rains with a calibrated simulator at rain intensities of 79 mm/h and 121 mm/h. They were evaluated hydrological parameters through water balance, such as runoff coefficient and steady infiltration rate, and also the control of the initial moisture in the layers of soil adjacent to the analyzed coatings. From the analyzed alternatives, the lawn soil showed the best results. It was verified that this coating did not generate the runoff for some cases, showing the potential of surfaces covered with vegetation to reduce the runoff. On the other hand, the portion with exposed soil generated a far superior runoff compared to the portion with lawn soil, presenting a runoff coefficient twice higher. The runoff verified in the solid concrete blocks was around 90% of the rainfall volume, four and a half times higher than the value presented in the surfaces with hollow concrete blocks coatings. The waterproof concrete lining and hollow concrete blocks were effective in reducing the runoff, corroborating with the values presented in the literature.