Nowadays, half of the world's population lives in urban areas, and the negative impacts of hydrological events have been recurrent due to growing urbanization, impervious soil coverage, and the consequent reduction in infiltration rates leading to decreasing aquifer recharge and surface runoff. Thus, runoff increases, intensifying peak flows and flood events. By contrast, green roofs have been applied for some time in several parts of the world both for architectural-aesthetic reasons and to improve environmental comfort. Moreover, they are also being used in view of their performance as an urban runoff control device. Considering actual characteristics and field data, an experiment was performed in order to investigate the water dynamics in two green roof systems. The Hydrus-1D unsaturated flow numerical model was used to process the data, considering different rainfall rates. The analyses of the hydrograms produced consistent qualitative and quantitative results, and it was possible to conclude that, for the climate conditions of the area investigated, green roofs are important devices to be used in the reduction of runoff from traditional roofs.
Eco house; Rainfall; Hydrus-1D; Urban drainage
