Hidrologia e hidráulica do escoamento de um telhado verde em ambiente tropical sob chuva natural e simulada

Abstract

The advancement of environmental technologies, combined with a short time to prepare the infrastructure of cities, made vegetated roofs emerge as a technique to mitigate the problems caused by urbanization, interfering with environmental control, and climate regulation, among other benefits to society. This work aimed to analyze the hydrological and hydraulic performance of the flows obtained in a green roof under natural and simulated rain, as well as its durability under a rainy tropical climate. To this end, masonry structures were installed in the field to support the roofs made of galvanized metal sheets of 2m² and 16% slope, subjected to natural rainfall and produced by a sprinkler infiltrometer, under a randomized block experimental design with three replications, during 04 months totaling 12 trials. The green roof delayed up to 63% of the surface runoff produced and abstracted from 42 to 56% of natural and simulated rainfall. The hydraulic resistance generated by the emerald grass of the green roof was dominated by the Froude number, demonstrating that in open flow low Reynolds values, were governed by gravitational forces. The Esmeralda grass showed a loss of durability in the period without rain. Finally, the green roof showed good hydrological and hydraulic results, proving to be efficient in reducing runoff, abstraction, and hydraulic resistance generated by the Esmeralda grass, demonstrating its importance in reducing the demands of conventional urban drainage systems.