The GIFLUID Project addresses the onset of flooding events in urban and sub-urban areas arising due to the impacts of climate change and the anthropic urbanization of the coastal landscape, which are two common challenges for the territories of Sicily and Malta. These cross-border territories present similar characteristics namely a semi-arid dry climate a prevalence of high intensity rain events, the historic urbanization of the low-lying areas of coastal catchments.
In the context of the admissible action of the Interreg Italia-Malta programme, the project aims to develop and promote practical tools which integrate the planning and design of green urban infrastructures (GUIs) in critical urban and sub-urban area of Sicily and Malta, to mitigate floods effects, to increase the infiltration of rainwater drainage improving also its quality.
WP1 concerns project management and WP2 dissemination and communication activities (seminars, training courses, workshops, etc.).
WP3 and WP4 promote the realization of green infrastructures in some demonstration plants.
WP5 includes modelling activities to evaluate the effects of green infrastructures on the reduction of hydraulic risk in urban and sub-urban areas, and the final editing of a master plan for the implementation of GUIs in some target areas located in Sicily and Malta.
In particular, the WP3 and WP4 envisage the construction of demonstration plants to promote some green infrastructures such as porous pavements (PP), rain gardens (RGs) and green roofs (GRs) in the territories of Sicily and Malta.
WP3 will promote Low Impact Development (LID) technologies, like innovative porous pavement (PP) and rain gardens (RGs) for storm water management.
PPs are able to address both water quantity and quality issues. PP is a particular Hydraulic Best Management Practices (BMPs) allowing storm water to seep directly into the ground (if the water quality permits) rather than running off into storm drains. As rain falls on the pavement, it infiltrates down into the storage basin where it is slowly released in the underground environment or conveyed to surface discharge systems.
RGs are landscaped depressions designed to infiltrate and filter storm-water runoff, containing vegetation and sometimes a drainage system. RGs are designed specifically to withstand high amounts of rainfall, storm-water runoff, as well as high concentrations of nutrients typically found in storm-water runoff – particularly nitrogen and phosphorus, minimizing the amount of rainwater that enters storm drains. They also help to trap silt and other pollutants that are carried by the runoff – as the water percolates through, it is treated by a number of physical, chemical and biological processes, removing loads of heavy metals and sediments, and thereby improving water quality and protecting local waterways from pollution.
These type of green urban infrastructures (GUIs), relatively cheap and easily implementable by the Public Authorities, can be designed starting from the urban planning stage, in order to reduce the flooding risk, and also settling of solids.
In Sicily a PP will be implemented in Aci Castello and a RG will be implemented in an area of UNICT. In Malta PP and RG demonstration sites will be implemented within the administrative area of the Rabat Local Council.
WP4 will promote the use of green roofs (GRs) in Mediterranean regions to mitigate the effects of the increased runoff peaks, volumes, and velocity. In particular, GRs are constructed of a lightweight soil media, underlain by a drainage layer, and a high quality impermeable membrane to protect the building structure. They are also passive cooling systems, which reduce incoming solar radiation from reaching the building structure. Green roofs are increasingly being used as a source control measure for urban storm water management as they detain and slowly release rainwater. Due to their water storage capacity, green roofs may significantly mitigate the runoff generation of most rainfall events. The mitigation consists in delaying the initial time of runoff due to the enhanced infiltration of water in the green roof system, reducing the total outflow volume by retaining part of the rainfall and evapotranspirating through vegetation, and distributing the outflow over a longer time period thanks to a relatively slow release of the excess water that is temporarily stored in the high porosity structure of the growing and drainage layers.
The objectives of WP4 are to provide detailed information about green roof performances in the Mediterranean climate (retained volume, peak flow reduction, runoff delay) and to identify a suitable modelling approach for describing the associated hydrologic response. A very important aspect will be also the identification of suitable plants in Mediterranean climate.
Two GR demonstration sites will be designed and realized in Catania and Malta. The sites in Catania will be an existing roof within the building of University of Catania where is located the Department of Agriculture, Food and Environment; in Malta, the roof will be realized within a public administrative building.
In WP5 the results from implemented demonstration GUIs (measures) will be integrated in a GIS-based model which will enable the modelling of runoff flows (and flooding) under different scenarios of GUI application (outputs). A policy paper on the application of GUIs as well as communication and dissemination activities will contribute to the promotion of the capacity building of GUIs in order to increase awareness of policy makers, public authorities/municipalities and other interested stakeholders (beneficiaries). A masterplan based on a GIS model and including a cost benefit assessment aimed at developing a methodology for the identification of the economically optimal application level of GUIs will be developed for two target areas.
The masterplan will also outline a methodology (tool) which can be used by agencies as blueprints for flood mitigation in similar scenarios. The adoption of GUIs will also provide an opportunity for addressing a cultural change in the population, by increasing awareness levels of critical hydrological events and how these can be managed (innovation) by adopting environmental sustainable options.