Sustainable managment of stormwater in a changing environment under Mediterranean climate conditions

Abstract

The problem of the increase in the magnitude and frequency of flooding events in urban areas can be approached by means of techniques of sustainable urban stormwater management. In this PhD dissertation, the effectiveness of one of these technologies namely the green roof (GR), has been investigated. For this purpose, a daily scale hydrological model for GRs, mainly based on meteorological data and with three levels of complexity has been proposed. Since, the evapotranspiration (ET) fluxes impact the GR retention performances, a study of the dynamics involved in ET process has been carried out. The use of green roofs technology in Mediterranean climate is very limited so two GR experimental benches has been placed in the campus of University of Salerno and preliminary results about the hydrological performances depending on the climate and constructions characteristics have been illustrated. Subsequently, the effectiveness of the proposed technology for the sustainable urban drainage management have been tested at a large scale and Sarno peri-urban basin has been presented as case study since it represents a hydrogeological hazard prone system. The analysis focused on the potential hydrological benefits in terms of peak runoff, peak delay and volume runoff in respect of several hypothetical scenarios of rainfall and GR retrofitting percentage. In high urbanized areas, the implementation of GRs at basin scale, allows a reduction of runoff rainwater from roofs close to 100% for some rainfall and greening scenarios. Where the GR retrofit potential is very low, satisfactory performances in terms of water management can be reached coupling this green technology to other sustainable techniques. [abstract editeb by Author]