A green roof experimental site in the mediterranean climate.

In January 2007 the Department of Civil, Environmental and Architectural Engineering (DICAT - University of Genoa), in collaboration with the Italian Green Roofs Association (AIVEP) and the Municipality of Genova, transformed the existing green roof of its hydraulic laboratory in an experimental site to investigate the green roof control potential on storm water management. The objectives of this study are to provide detailed information about green roof performances in the Mediterranean climate and to identify synthetic parameters for describing the associated hydraulic behaviour (retained volume, peak flow reduction, runoff delay). Two different approaches were implemented to simulate the hydraulic response of the experimental green roof: the Hydrus – 1D model, that solves the Richards' equation for one-dimensional saturated-unsaturated water flow, and a simplified linear reservoir model. In the latter model, three reservoirs are used to simulate percolation in the growing medium, and drainage from the saturated and unsaturated zones. Data colleted during the initial monitoring campaign (from May to November 2007) are presented in the paper, together with preliminary results obtained in simulating the storm water source control potential at the experimental site.