Relação chuva-vazão nos telhados verdes modulares sob chuva simulada induzida.

• Autor(a) principal: Nascimento, Cláudia Maria Loiola do
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/11019
• topic: Environmental Engineering; Green roof; Vegetated roof; Runoff reduction; Hydric retention; Simulated rainfall; Engenharia Ambiental; Telhado verde modular; Telhado vegetado; Redução do escoamento superficial; Retenção hídrica; Chuva simulada; CNPQ::ENGENHARIAS

The loss of natural vegetation and the increase of impermeable surfaces due to the urban expansion have shown that the traditional urban drain systems are ineffective and not much adaptable to the changes of ground use. One of the consequences is the increase of the speed of runoff, which furthers flood, with great material and environmental damage. The flood usually occurs because of stormwaters. The aim of this essay was to study the modular green roofs contribution, submitted to storms, 155mm/h lasting 7,0 minutes, in retention and delay of runoff. Besides, values were determined for these rain-flow classic model parameters: Rational method (C) and CN (SCS), which will be used for hydrological modeling of the effects of using green roofs to control urban flood. The methodology used is experimental and involved building worktops with adjustable inclination to support the experimental modules and a system for controlled induction of rain intensity. Three modular system models were studied for green roof which allow the storage of water at the bottom of the tray that the modules are made up, two are 17,0 L (M-17 and F-17) and one is 4,0 L(M-4), in dry soil and moist conditions. In each vegetated module three species of vegetation were used: Portulaca oleracea, Callisia repens e Apnia Cordfolia. The results show that the retained volume, calculated through observing the runoff, in different situations, are coherent with each other and have data reported in literature. The vegetated modules produced the best results with dry soil and the worst results with moist soil. The average percentage of retention, considering all the types of modules, was 58% of the total volume of induced water, with a 12 minute average delay on runoff. The average values of C (Rational method) were 0,4; 0,48; 0,36, to modules M-17, M-4 and F-17, respectively and the ones for CN (SCS) were 93, 95, 93, to the same modules. As expected, the greatest CN values were the ones for moist ground, keeping the relation of lesser retained volume and more runoff and CN. The module F-17 presented better performance in all aspects (flow reduction, hydric retention, runoff delay). This study shows the good contribution this kind of system may provide for retention and delay runoff, even for short duration heavy rains, mainly after dry season, common situation in places with tropical weather. Future studies should assess the green roof s performance of modular systems accounting other characteristics and types of rain s intensity. Adopting green roofs must be cautious, especially the extra burden that such a system is.