Multi-source spatial data for a better management of rainwater and urban cultivated areas: a case study in Rome, Italy

In the last decade citizens interest toward local food production, food sustainability and environmentalstewardship has grown exponentially and urban agriculture (UA) is nowadays one of the answer to this newcollective awareness. The analysis of the spatial dimension of UA in metropolitan areas is the starting pointfor investigating its characteristics, the positive impacts on the urban environment and, in general, for abetter planning and management of green and vacant spaces. This contribution explores the spatialdistribution of residential cultivated parcels in the urban area of Rome and their sustainability in terms ofwater required for irrigation. In particular, the water required for growing crops during the summer season(April-September) was estimated by using data on land use and parcels size. Later, the share of irrigation thatmight be provided from the rainwater harvestable from roofs nearby parcels was computed by using themonthly rain average for the period 1950-2010 and the roofs size. Data on cultivated residential areas in2013 were created by photointerpretation of the very high resolution imagery provided by Google Earth.Updated roofs polygons were not available on official maps, so an automated objected oriented classificationon WorldView2 high resolution imagery was used. The method proposed provide a preliminary assessmentof one of the component of urban water use that might be useful to support sustainable urban watermanagement actions.