Assessment of the food-water-energy nexus suitability of rooftops: a methodological remote sensing approach in an urban Mediterranean area

Abstract

This work established a framework to identify and analyze the technical feasibility of roofs for integrating urban agriculture, rainwater harvesting, and photovoltaic systems using various remote sensing. The framework was applied to a region north of Barcelona. Three levels of solar access requirements for tomatoes, leafy crops, strawberries, and microgreens were established. The case study included compact and disperse urban forms, residential and nonresidential building uses and various building typologies. It was identified that 8% of the roof area is feasible for tomato and lettuce production, and production could satisfy the 210% of average intake of tomatoes and the 21% average yearly consumption of lettuce. Rainwater harvesting systems could supply 94.26% of the water requirements for lettuce growing in an open-air system; in contrast, 53% of irrigation could be satisfied for tomato production in rooftop greenhouse systems. The results showed a potential for 80% of roof area to be used for rainwater harvesting systems, representing the average yearly water consumption of 44% of citizens for laundry, showering, toilet flushing, cleaning and irrigation uses. Finally, 50% of the roofs are suitable for photovoltaic panels, representing an average energy consumption of 18% of citizens.

This work is part of the Fertilecity II project supported by the Spanish Ministry of Economy and Competitiveness (CTM2016-75772-C3-3-R and CTM2016-75772-C3-1-R, AEI/FEDER, UE); from the Spanish Ministry of Science, Innovation and Universities. This research has received financial support from the European Union's Horizon 2020 research and innovation program under grant agreement No 862663. The publication reflects the author's views. The Research Executive Agency (REA) is not liable for any use that may be made of the information contained therein. This work was supported by the “María de Maeztu” program for Units of Excellence in R&D (CEX2019-000940-M). Authors want to thank to Assumpció Termes and Fernando Pérez-Aragüés from the Institut Cartogràfic i Geològic de Catalunya for their valuable support, to the Greenhouses to reduce CO2 on Roofs (GROOF) project, to the reviewers and editor for their observations, also to the Secretaria d'Universitats i Recerca del Departament d'Economia i Coneixement de la Generalitat de Catalunya for the award of a research scholarship (FI-DGR 2018) to Joan Muñoz-Liesa and to the University of Guadalajara (Mexico) for awarding a research scholarship to Perla Zambrano-Prado.

Peer Reviewed

Postprint (published version)