Urban Forestry & Urban Greening 44 (2019) 126389 Contents lists available at ScienceDirect Urban Forestry & Urban Greening journal homepage: www.elsevier.com/locate/ufug Feasibility assessment of rooftop greenhouses in Latin America. The case T study of a social neighborhood in Quito, Ecuador Ana Nadala, ,1, Daniel Rodríguez-Cadenaa,1, Oriol Ponsb, Eva Cuervac, Alejandro Josad,e, ⁎ Joan Rieradevalla,f a Sostenipra Research Group (SGR 01412), Institute of Environmental Sciences and Technology (ICTA), Z Building, Universitat Autònoma de Barcelona (UAB), Campus UAB, 08193, Bellaterra, Barcelona, Spain b Department of Architectural Technology I, School of Architecture (ETSAB), Universitat Politècnica de Catalunya (UPC-Barcelona Tech), Avinguda Diagonal 649, 08028, Barcelona, Spain c Department of Projects and Construction Engineering (DEPC), Universitat Politècnica de Catalunya BarcelonaTech. Diagonal 647, Ed. H, 08028, Barcelona, Spain d Department of Civil and Environmental Engineering (DECA), Universitat Politècnica de Catalunya (UPC-BarcelonaTech), Campus Nord, C/Jordi Girona 1-3, 08034, Barcelona, Spain e Institute for Sustainability Science and Technology (IS.UPC), Universitat Politècnica de Catalunya (UPC-BarcelonaTech), Campus Nord, C/Jordi Girona 31, 08034, Barcelona, Spain f Department of Chemical, Biological and Environmental Engineering, Universitat Autònoma de Barcelona (UAB), Campus UAB, 08193, Bellaterra, Barcelona, Spain ARTICLE INFO ABSTRACT Handling Editor: Cynnamon Dobbs Today, food security has a critical place in the government agendas of developing countries. In Latin American Keywords: case, urban contexts have been subject to radical transformations in the last decades, most apparently through Urban agriculture the expansion of social housing, which may limit or condition access to food for the neediest population. Hydroponic Nowadays, in Latin America, there are numerous cases of urban agriculture. Quito (Ecuador) stands out for the Sustainable cities development of urban agriculture through the Participatory Urban Agriculture Project - AGRUPAR; initiative Food security that has led to the implementation of orchards with organic production, raising of small animals, food processing Food self-sufficiency and marketing of surpluses for food-nutrition security. Above all, it has transcended its urban and peri-urban Rooftop greenhouse intervention to rural areas, favoring the urban-rural connection. Also, worldwide the urban agriculture is de- veloped in different forms, one of which is through crops protected by a greenhouse on the roofs: Rooftop greenhouse (RTG). This form of UA uses specific substrates for hydroponic crops and has modern irrigation systems often combined with rainwater harvesting and provides a unique opportunity to improve urban agri- culture in Quito. The purpose of this study is to identify the implementation potential of rooftop greenhouses in social neighborhoods in Quito. Standard methods to assess the potential use of rooftop greenhouses were adapted to a social neighborhood. The guidelines follow three steps: Step 1: Characterization based on criteria; Step 2: Available surface determination and Step 3: Production, self-sufficiency and self-supply. “La Comuna Santa Clara de San Millán” was selected as study area. The results showed that 33.2% (7.70 ha) of the neighborhood rooftops had a short-term feasibility to install rooftop greenhouses, with the potential to produce 1,579,140 and 56,720 kg/year of tomato and lettuce respectively. The research has developed reliable guidelines that prove the feasibility to install rooftop greenhouses in similar large Latin-American cities area. 1. Introduction. Participatory Urban Agriculture prevent the negative effects on food flows caused by a quick urbani- zation process(Halloran, 2011; Wadel et al., 2010; Willett et al., 2019) Today, urban agriculture (UA) emerges as a tool to mitigate and and is gaining support as an important part of the solution ABBREVIATIONS: AGROCALIDAD, Agriculture Ministry Agency; CSCSM, Comuna Santa Clara de San Millán; DMQ, Metropolitan District of Quito; AGRUPAR, Participatory Urban Agriculture Project; RC, Reinforced concrete; RTG, Rooftop greenhouse; UA, Urban agriculture ⁎ Corresponding author at: Edifici ICTA-ICP, Carrer de les Columnes, 08193, Bellaterra, Barcelona, Spain. E-mail addresses: ana.nadal@uab.cat, ana.nadal.fuentes@gmail.com (A. Nadal), danielo_66@hotmail.com (D. Rodríguez-Cadena), oriol.pons@upc.edu (O. Pons), eva.cuerva@upc.edu (E. Cuerva), alejandro.josa@upc.edu (A. Josa), Joan.Rieradevall@uab.cat (J. Rieradevall). 1 Ana Nadal and Daniel Rodríguez-Cadena contributed equally to this paper and share first authorship. https://doi.org/10.1016/j.ufug.2019.126389 Received 27 November 2018; Received in revised form 10 May 2019; Accepted 8 July 2019 Available online 20 July 2019 1618-8667/ © 2019 The Authors. Published by Elsevier GmbH. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/BY-NC-ND/4.0/). A. Nadal, et al. Urban Forestry & Urban Greening 44 (2019) 126389 (Despommier, 2011; Maxwell, 2000; Maxwell et al., 1999; Orsini et al., American cities (Table 1). 2013; RUAF Foundation, 2015; Zezza and Tasciotti, 2010). Urban Ecuador is widely recognized for its socially focused UA system. In agriculture is developed in different forms, one of which is through April of 2000, the Quito Declaration took place in Ecuador, which was crops protected by a greenhouse on the roofs: Rooftop greenhouse signed by representatives of 27 cities in 10 Latin-American and (RTG) (Nadal et al., 2015; Sanjuan-Delmás et al., 2018). This form of Caribbean countries, with a commitment to develop and promote UA in UA can use hydroponic systems providing temperature control, redu- the region (FAO, 2014b, 2012). These UA developments were based on cing evaporative water loss, preventing control of disease and pest in- the urban-architectonic features shared by cities in this region, with fections, and protecting against the changing weather(Montero et al., free and horizontal roofs. On an urban scale the extensive use of UA in 2017; Ana Nadal et al., 2017; Pons et al., 2015). Hydroponic systems a Quito is remarkable (CONQUITO, 2009; FAO, 2014b). soilless technology, are more efficient than other soil systems, is the Specifically, the city of Quito stands out for the development of the fastest growing and second generation of crop production system in Participatory Urban Agriculture Project - AGRUPAR; a program that agricultural industry. promotes self-production of food as a strategy of contribution to food- Hydroponic systems include this benefits: reduce water consump- nutrition security(CONQUITO, 2009). This project has allowed the in- tion, use liquid nutrients wich is recirculating all over the system, no crease of biodiversity, the recovery of public and private spaces for nutrient waste due to water runoff, irrigation water is supplied directly productive purposes, allowing access to healthy food for the entire to root areas, efficient use of fertilizers and cost saving, achieving up to population. The above, through the implementation of orchards with five times more productivity in less space due to reducing substrate use, organic production, raising of small animals, food processing, and lightining and reducing the crop weight and therefore their loads on the surplus marketing. The urban agriculture project has transcended its building structure (Dubbeling and Massonneau, 2014; Sanyé-Mengual urban and peri-urban intervention to rural areas of the urban district, et al., 2015a, 2015b; Chow, Y. N et al, 2017). favoring the urban-rural connection, within the City-region approach. In some high densely populated cities, where soil availability is In addition, AGRUPAR has promoted the accession of Quito to the Pact limited, RTGs has been installed for vegetable production (Baker, 2000; of Food Policies of Milan(CONQUITO, 2009). Germer et al., 2011; Montero et al., 2017; Peng and Jim, 2013; Tian Additionally, most people in Latin America live in single family et al., 2012). As an example in developed countries, in New York, Go- houses(Gilbert, 2011). In this sense, the growth of Latin American cities tham Green has 1400 m2 of RTGs and aims to reach 18,000 m2 and The is linked to the construction of social housing neighborhoods; however, Vinegar Factory produces its own vegetables and fruits in 830 m2 of and according to Nieto (1999), the housing deficit of the region has RTGs. In Montreal, Canada, Lufa Farms has built 2900 m2 of RTGs increased year after year. Millions of Latin American families live in (Sanyé-Mengual et al., 2015a). There are also interesting experimental unfinished homes since the construction of houses tends to develop experiences. For example on the rooftop of ICTA-ICP (Environmental gradually and depends on the income of each family(Gilbert, 2011). Cience and Technology Institute and Catalonian Paleontology Institute) Despite the construction by stages, the houses are usually built with building at the Autonomous University of Barcelona, there is an in- resistant materials(Cerón-Palma et al., 2013), since socially housing is tegrated RTG in which CO2, energy and water connected flows between considered an asset to the economy of families(Gilbert, 2011). There- the RTG and the building are studied so they can improve the edifice fore, this type of building has minimum requirements that allows the metabolism (A. Nadal et al., 2017b) use of roofs and other spaces for the implementation of vertical urban In this sense, Latin-American countries such as Argentina, Brazil and agriculture (A. Nadal et al., 2017a, Nadal et al., 2018). Cuba have approved policies and programs to promote UA (Moran- In this sense, the present research aims to identify the im- Alonso, 2011; Moran-Alonso and Hernandez, 2011; Orsini et al., 2013; plementation potential of rooftop greenhouses in social neighborhoods Rojas, 2016).There are also several examples of UA as an initiative led in Quito. To do so it develops a new version of a previous guideline by local governments, organizations and multilateral organisms (mostly through an interdisciplinary scope, which was applied in a neighbor- FAO), which aim to encourage involvement from the unemployed and hood selected for the research. This article has the 3 following specific socially excluded population, in order to improve their socio-economic objectives: 1) carry out research about existing guidelines for installing conditions, malnutrition and confront famine(Baudoin et al., 2013; RTGs to take relevant cases that could be useful in Latin-American cities Cerón-Palma et al., 2012; Colinas et al., 2018; De la Sota et al., 2018; and adapt them to a series of guidelines for social Latin American FAO, 2014a; Hou and Grohmann, 2018; La Rosa et al., 2014; Nastran neighborhoods; 2) In spite of the different types of cities in Latin et al., 2019; Orsini et al., 2014). America, we seek to identify a social neighborhood in Quito, Ecuador, A real example is La Habana, Cuba, which uses 12% of its surface as a case study with the most representative characteristics of Latin area for UA, to grow organic crops mainly for self-consumption (Cruz American cities to test this guide.; 3) determine the available surface and Sánchez-Medina, 2003). There are also further cases of UA in Latin- area for a short-term use of RTGs, and then estimate the potential Table 1 Urban Agriculture experiences in Latin America. Country City Kind of orchard Number of Production Ton/ Urban Beneficiaries Reference orchards year Farmers Argentina Rosario Household – – 1800 – FAO, 2014 Brazil Belo Horizonte Household 233 – – – FAO, 2014 Colombia Bogotá Household – – 10,000 8,500 Families FAO, 2014 Antigua and Conglomerate of cities Household – 280 – – FAO, 2014 Barbuda Cuba La Habana Household – 6700 90,000 30,000 inhabitants Liendo and Martínez, 2006; FAO, 2014 México Ciudad De México Household 12,300 – – – Torres-Lima et al., 2010 Bolivia El Alto Household – – – 89,000 inhabitants FAO, 2014 Nicaragua Conglomerate of cities Household 250,000 – – – FAO, 2014 Ecuador Quito Household 800 – 10,250 – FAO, 2014 Communitarian 140 – – Scholar 128 – – 2 A. Nadal, et al. Urban Forestry & Urban Greening 44 (2019) 126389 results: production, self-sufficiency and the surface area needed to self- East of DMQ that extended the boundaries of the city (Correa, 2012). supply. This could allow to identify the potential of RTGs to achieve Third, at the beginning of 21 st century, the new Metropolitan Land Use food security and social urban rehabilitation. Plan for the DMQ 2012–2022 (PMOTDMQ) priorized vertical growth and city densification, leading to a second ongoing compaction process (Jaramillo and Van Sluys, 2012; MDMQ, 2012a; Vaca, 2015). These 2. Background. Urban context and urban agriculture of Quito phases have defined the present mixed urban conformation, none- theless, it is still mainly has a disperse configuration and therefore si- The high rates of urbanization have led to the development of high milar to most Latin-American cities (Garza, 2009; Quintero and Gómez, concentrations, becoming the most urbanized region in the world after 2012). Therefore, studies and experiencies in Quito can be used as a North America. Although the cities of Latin America are heterogeneous reference for the region. and there are different typologies; there are common challenges and There are numerous DMQ particular conditions that make Quito problems(NU. CEPAL, 2013): specially suitable for UA experiences. For example the local building guidelines, the technical rules for architecture and urbanism, consider • High degree of urban primacy the residential agriculture as a land use (MDMQ, 2011). Quito's location • Urban growth disjointed in the periphery of cities and weather conditions also favor UA (Appendix A), with mid-high • High rates of socio-spatial segregation precipitation and stable temperatures throughout the year, and optimal • Cities with a monocentric development sunlight hours for agriculture production (MDMQ, 2012a, 2012b). The • Absence of clear and efficient urban development policies that allow demographics features (rural-urban migration) and architectural fea- integral development tures of Quito also endorse UA, with a dense city with unfinished buildings (useless spaces with UA potential) located in peripheral areas Of which, Quito presents the great majority of these characteristics. (Correa, 2012; Figueroa, 2012). Other criteria were defined for its selection as a case study: In Quito the main construction material is reinforced concrete, a) Socio-economic conditions roughly 75% of the households are build on this material and have b) Technological level unfinished rooftops (INEC, 2010). This is relevant for RTGs assessment c) Structural characteristics and local environmental context and showed a potentiality to its implementation. Moreover, there are d) Framework of an urban planning system vulnerable sectors, in which there is a need for food security and access Quito represents the dominant center in Ecuador and presents socio- to acceptable food. This is fundamental for decision makers, whom economic segregation, which accounts for important differences in require well planned methods to consider the use and installation of UA vulnerability in different areas of the city. It presents an important facilities, in particular RTGs, when the urban layout and architecture growth in terms of land occupation, changing the use of soils in peri- make this option feasible. urban areas. To delve into the subject, the main characteristics of Quito as a case study are presented below(NU. CEPAL, 2013). The Metropolitan District of Quito (DMQ), has a 565 inhabitants per 3. Methodology km2 density and 3,8 inhabitants by home, considered as a disperse city, which is on the way of becoming a compact city due to new urban 3.1. Guideline adaptation regulations, therefore, nowadays it is a mix of high density and low density areas located in differentiate areas (Correa, 2012; Jaramillo and Existing guidelines for installing RTGs have been analyzed and an Van Sluys, 2012). The same process of compaction is happening in adaptation was made from two researchs developed in Barcelona by other Latin-American cities (Garza, 2009). High density or compact Sanyé-Mengual et al. (2015a, 2015b) and Nadal et al (2017a) and fo- cities are areas that are characterized by population concentration in cused on several factors to determine the economic viability of instal- buildings where several families live, on the other hand on a low ling RTGs. The guidelines follow three steps shown in Fig. 1. density or disperse city, consists on single family households with Relevant aspects of the guidelines were used together with features neighborhoods with lower construction diversity (Chavoya et al., that were developed for this research to define the proposed guidelines, 2009). presented in Table 2. These guidelines have been applied to analyze the There were three important phases during its urban configuration. feasibility of RTGs implementation in the study area. First, during the first half of the 20th century, its growth focused on a North-South axis, generating an urban expansion process without pre- • Step 1: Characterization based on criteria cedent, based mainly on an important migration flux from rural areas (Clavijo, 2013) that consolidated the compact urbanization process of The following three criteria were applied and adapted for this re- DMQ (Correa, 2012). Then, the second half of 20th century was char- search: urban, agronomic and technical. Urban criteria include 2 as- acterized by an exponential urban growth in the valleys located at the pects; the legal background, which considered a revision on rules, Fig. 1. Methodology diagram based in Sanye-Mengual et al., (2015) and Nadal (2017) guidelines. 3 A. Nadal, et al. Table 2 Graphical representation of the methodology (guide specifications) proposed for identifying the feasibility of RTG implementation in social neighborhood in Quito. STEP 1 CRITERIA ASPECT REQUIREMENT IMPLEMENTATION FEASABILITY RESOURCES AND TOOLS Direct Middle and long- Short-term term Digitalization: polygon Digitalization: point * CHARACTERIZATION BASED ON Urban Legal Rules, ordinances, development plans X X Local official documentation. CRITERIA and other official local documentation. Websites of local institutions.** Roof top surface Covers > 10 m2 ** X Local cadastral plan, orthophoto. available Free of occupation (Antennas, water X GIS tanks, water heaters, craft workshops) * Agronomical Social Agricultural Tradition and previous X Historical Documents and Data about knowledge rurality migraton living in the area, interviews**. Sunlight availability Minimum: 4-6 hours of sunlight X X Local secondary information. NASA Surface ** meteorology and solar energy (web application)** * Technical Architectural Load Capacity X X Orthophoto or site inspection. GIS Rooftop Material* Reinforced concrete X Orthophoto or site inspection. Metal X GIS 4 Asbestos X Zinc X Roof tile X Palm or straw X Slope* Flat X X Orthophoto or site inspection. Inclined X GIS Gabled X Hipped X Convex X STEP 2 AVAILABLE SURFACE Middle & long term Rooftops were digitalized as polygons, to obtain available surfaces considering criteria defined on DETERMINATION available surface Step 1 Term available surface Middle and Long-term implementation required an reconstruction to adapt the roof for an RTGs (ha) structure STEP 3 PRODUCTION, SELF-SUFFICIENCY & Selected vegetables kg Production (kg /year ) = Potential Area (ha)·Vegetable output SELF-SUPPLY ( ha year ) Production (kg ) Self sufficiency (persons/year ) = kg average vegetable intake percapita·año kg average vegetable intake *population percapita·año * * Self supply surface (ha) = kg Vegetable output ha Urban Forestry & Urban Greening 44 (2019) 126389 A. Nadal, et al. Urban Forestry & Urban Greening 44 (2019) 126389 Fig. 2. Location of social neighborhood Comuna Santa Clara de San Millán. ordinances, development plans, laws and other official documentation • Step 3: Production, self-sufficiency and self-supply from the study area location, at local and national level, to determine conditions which could limit or enhance RTGs implementation. Also, Finally, production, self-sufficiency and self-supply were measured environmental regulations on UA and RTGs were analyzed, and finally taking the surface results obtained for short-term feasibility im- commercial regulations were checked and insititutional background is plementation, two Eqs. (1)and (2) where obtained from an assessment reviewed. The roof top surface available were analyzed as well, related for RTG feasibility (Sanyé-Mengual et al., 2015a), and the third equa- with self-supply and food security at household level, which considers tion was developed to measure self-supply capacity, to take into ac- that the needed surface to produce enough vegetables for a family of count the space needed to supply a determined population, which is four people is 10 m2 (FAO, 2005; Jeavons and Cox, 2007), in this sense relevant for this research. There were considered no difference between lower surfaces will be considered as not feasible. Besides, in order to periods because the productivity in greenhouses remains similar all facilitate RTGs implementation, it was determined that potential sur- year in this region. The equations used were the following: faces must be free of permanent equipment, like solar panels, climati- kg zation equipment, water tanks among others. Nonetheless, the surface Production (kg / year ) = Potential Area (ha)· Vegetable output can also be considered as feasible if this equipment can be removed. ha year Second, the Agronomiccriteria, here social aspects were including as (1) an additional feature on the guidelines. The knowledge of a specific Production (kg ) territory and population could be linked to agricultural capacities re- Self sufficiency (persons / year ) = lated to the rural migration to the cities, as well as the historical context average vegetable intake ( kg percapita·año ) of community. Settlements around the old town in cities used to have (2) agricultural land use. On the other hand, the main factor which limit agricultural production is sunlight hours was considered because it is Self supply surface (ha) fundamental for vegetative growth and thus for RTGs implementation (shadows related of proximity buildings must be considered). = average vegetable intake ( kg percapita·año )*population Third, the Technical criteria, architectural features were analyzed, the structural capacity of buildings is important to determine whether it Vegetable output ( ) kg ha (3) would support an RTG on its rooftop, therefore, guidelines for buildings There were chosen two highly demanded vegetables to use the design, which show structural capacity and security regulations were equations, which avarerage intake per year and output were obtained researched. Feasibility clasification is based on rooftop construction from secondary sources, in order to estimate the RTGs potential benefits materials (reinforced concrete, steel or timber structure and asbesto that would be obtained through their implementation. It could use for cement, zinc, roof tile, palm or straw finishing layers) and slope (flat, any crop and could be analyzed with multicrop as well. pitched, gabled or hipped roof). 3.2. Methods: Application to a case study • Step 2: Available surface determination 3.2.1. Case study These considerations from Step 1 were used to separate short-term The social neighborhood, “La Comuna Santa Clara de San Millán” feasibility from middle and long-term feasible RTGs implementation. (CSCSM) (Comuna: minor administrative subdivision corresponding to Geographical data analysis was made using ArcGis 10.2 (ESRI, 2013). It an urban, rural, or mixed area). was selected as study area (Appendix consisted in counting all buildings determined as middle and long term B). feasible, digitalizing them as a point, and measuring all short-term The CSCSM it is located in Northwestern zone of Quito (Fig. 2), on feasibility RTGs implementation, digitalizing them as polygons. The the foothills of Pichincha Mountain, which limits its expansion. Re- data source were orthophotos obtained from a project of Ecuadorian garding to services there are a coverage of potable water of 64%, Agriculture Ministry of (SIGTIERRAS, 2016), and satellite pictures ob- sewage system 77%, electricity 99% and 38.1% finished roads (pave- tained from Google™Earth (Capture date: March16th, 2016). ment, pavement cobble and concrete). Neighborhoods located next to 5 A. Nadal, et al. Urban Forestry & Urban Greening 44 (2019) 126389 Fig. 3. Map of Comuna Santa Clara de San Millán, Land Use. foothills present similar characteristics because of their similar topo- parcels while area A has 1–3 storey buildings (MDMQ, 2014), and graphy and natural conditions (Carrión and Erazo, 2012). These parcels have lower built surfaces (Table 3). neighborhoods also have the same structure than those located on peripherical rings, considered as disperse areas, that form the city (Jaramillo and Van Sluys, 2012), which made a portion of CSCSM also 3.2.2. Local data representative of this areas. To sumarize, this neigborhood has two Specific data are needed for the application of the present metho- different areas, which represent a compact and disperse (peri-urban) dology in the case study, in Step 3, to determine these parameters, area respectively. tomato and lettuce were selected, considering two of the most con- In order to improve the assessment of this study results and based on sumed vegetables in Quito and representative of Ecuadorian diet what was indicated by Schneider and Woodcock (2008), the CSCSM has (MAGAP, 2016). They have a big difference in demand and pro- been divided in the following two areas (Fig. 3): ductivity. Respective values of consumption per capita of 5.43 and 056 kg·habitant−1 year−1 were used (MAGAP, 2016). The production • Area A: Disperse zone with great heterogeneity, low construction considered for these vegetables with Ecuador hydroponic greenhouse density (with irregular blocks related with its topography) and nu- features, were 192,000 and 7900 kg·year−1 respectively (AIC, 2003; merous green areas, which is representative of peri-urban cities. Rendón and Yance, 2012). These productions were distributed in areas These areas are not parceled and end being occupied illegally by A (tomatoes) and B (lettuces) in order to obtain self-sufficiency capacity precariously built constructions from migrants. of two different types of vegetables, with different performances, for all • Area B: Compact zone, with a relative homogeneity and high con- Quito's urban population. For self-supply the population of CSCSM struction density WITH orthogonal shaped blocks, which is re- (8862 inhabitants) was considered, (INEC, 2010). The sources used in presentative of compact cities. the equations were gathered from secondary local sources, with ex- pirience in vegetable production in traditional greenhouses (AIC, 2003; Regarding to their constructions CSCSM presents unfinished build- Rendón and Yance, 2012). ings that are mainly households owned by single families (Fig. 4). Area B is full of 3–4 storey buildings 12–16 m high that occupy their whole Fig. 4. Detail of unfinished housing of the CSCSM. 6 A. Nadal, et al. Table 3 CSCSM Criteria analysis. CRITERIA ASPECT REQUIREMENT RESULT RESOURCES AND TOOLS * Urban Legal Rules, ordinances, development plans and There is an ordinance related with Land Use (MDMQ, 2011a) that establishes UA as a land Local official documentation. other official local documentation. use. In the urban planning and construction laws attached to this ordinance, green roofs are Websites of local institutions. considered and described, which not include RTGs, giving general requirements for their Local cadastral plan, orthophoto. implementation and construction methodologies, also mentioning their classification, GIS importance and economic and environmental benefits. Nonetheless, in this document, green roofs are considered mainly as aesthetycal features (MDMQ, 2011b). Furthermore, CSCSM has a metropolitan ordinance (MDMQ, 2014) which is a sustainable development plan for the neighborhood that includes guidelines related to land use. It establishes that all areas could apply ecological protection, which includes UA inside land use regulations. Roof top surface Covers > 10 m2 The maximum surface found in the study area was 250 m2. Studied rooftops were between available Free of occupation (Antennas, water tanks, this minimum and maximum surface values and classified in the three following categories: water heaters, craft workshops) 10-90, 90-170 and 170-250 m2, the selected ranges were applied to have similar intervals between them. * Agronomical Social Agricultural Tradition and previous knowledge The CSCSM has 35% of rural origin population (INEC, 2010; Larrea et al., 2009; MDMQ, Historical Documents and Data about rurality 7 2011b) with experience on agriculture practices that will improve RTGs implementation migraton living in the area, interviews. results. In addition, in the CSCSM, urban orchards were found, which are mainly focused in self-consumption. ** Sunlight availability Minimum: 4-6 hours of sunlight Sunlight hours in Quito vary little during the year because it is located close to Ecuadorian Local secondary information. NASA Surface meridian. To obtain this data the Atmospheric Science Data Center was used (NASA, 2016), meteorology and solar energy (web application) and an availability of 121 sunlight hours per day during all year, without seasonal differences was found, which covers the requirement of between 4 and 6 sunlight hours for UA (FAO, 2003). Technical Architectural * Load Capacity Reinforced Concrete (RC) in Ecuador have a load capacity of minimum 200 Kg/cm Orthophoto or site inspection. GIS Rooftop Material* Reinforced concrete (MIDUVI, 2014), Quito buildings have RC columns and solid load bearing slabs with Orthophoto or site inspection. GIS Metal masonry non-load bearing facades. Most roofs, about 75 %, are RC slabs without any other Asbestos material or layer on top. These roofs lack finishing, waterproof or insulation layers. The Zinc rest of roofs have metallic, asbestos cement or zinc finishing layers leaning on a light Roof tile structure of steel or timber joists and beams (INEC, 2010). Older buildings have load Palm or straw bearing rammed earth walls and pitched roofs with light joists and beams covered with Slope* Flat roof tiles. Orthophoto or site inspection. GIS Inclined Gabled Hipped Convex Urban Forestry & Urban Greening 44 (2019) 126389 A. Nadal, et al. Urban Forestry & Urban Greening 44 (2019) 126389 3.3. Results of the case study needed for self-supply was compared with available surface for the three ranges used, showing that from 10 to 170 m2 would self-supply 3.3.1. Quantification of the potential area for RTG tomato and lettuce for the neighborhood but the 170-250 m2 range Step 1: Characterization based on criteria. Regarding legal back- would only achieve self-supply of tomato (Table 4). ground, in Ecuador there is the National plan of good living 2013–2017 Self-sufficiency equation showed that the study area would cover (SENPLADES, 2013), which consists in national guidelines for public 9% and 4.5% of Quito's demand of tomato and lettuce respectively, affairs. This plan aims to promote, develop, guarantee and transversa- which shows the big potential of RTGs implementation because CSCSM lize social cohesion, and local and national environmental sustain- represents only the 0.17% of Quito's area (INEC, 2010; MDMQ, 2012b). ability. However, the Agriculture and Environmental Ministries do not Results showed that only 5.8% and 14.6% of surface of the first range of include UA in their plans. Moreover, Environmental Ministry activities available rooftops, 10 to 90 m2, would be required to self-supply CSCSM catalog to get environmental licenses does neither include nor stan- (Table 5). This presents an opportunity for using all other available area dardizes UA activities. to produce other vegetables demanded for CSCSM residents, which On the other hand, in Quito, UA is included in municipal planning could be cover with the remaining surface, and perhaps surplus for as an objective (MDMQ, 2012a) and guidelines for performing it are commercialization could also be obtained. If the previous case is de- specified in the Urban planning and construction law (MDMQ, 2011). monstrated, the self-supply production could be focused in the first Fresh food production is regulated by an Agriculture Ministry agency range (10-90 m2), while surplus production could be cropped as (AGROCALIDAD) and by Ecuadorian Institute of Normalization (INEN) monoculture in medium and bigger range surfaces (90-250 m2). Com- which establish law for vegetable production, packaging and all mea- mercialization would be done using the existing structure in Quito for sures needed from distribution to sale (AGROCALIDAD, 2013; INEN, UA products. 2011, 1996). Besides, there is a guideline for good practices specific for tomato cultivation (AGROCALIDAD, 2015). 4. Discussion CSCSM differs from other neighborhoods because it is led by a council composed of five members, which control activities and rela- Methodology for agricultural production on residential roofs. tions with external stakeholders. This council is elected each year by The presented methodology turns out to be a tool with great po- CSCSM households’ owners. This is an advantage to apply a new ex- tential in the residential urban contexts in comparison with those de- perience such as RTGs, because the implementation process would be veloped by Nadal et al. (2017)and Sanyé-Mengual et al. (2015a), be- done supported by the neighborhood owners’ representatives. cause these focus in urban industrial contexts. Finally, Quito has an ongoing experience in UA, primarily in- Specifically, the modifications were: 1) In the legal background, centivized by AGRUPAR project, which assembles urban farmers and institutional review was included, to assess possibilities of institutional 380 communitarian organizations who work in UAs, and is supported support on a future RTGs implementation 2) the size of rooftops found by NGOs, Quito's municipality and universities (Duenas, 2010). This in the study area were shorter than the value of 500 m2 determined as project has promoted commercialization of products holding fairs feasible in the followed guidelines, therefore, new considerations were called "bioferias", to attract consumers with organic and urban soil necessary to classify them, thus considering a minimum surface based agriculture products. It started to incentivize the use of balconies and on self-supply capacity at household level was chosen. 3) Despite the rooftops in zones without access to soil, promoting vertical UA in Quito, base guidelines mentioned sunlight influence in RTGs implementation, using recycled materials (FAO, 2014b). related to crop growing capacity, a measure methodology was not Step 2: Available surface determination. First data was gathered mentioned, in this sense, in the proposed guidelines, sunlight de- from Quito municipality dependencies. Then base geographical data termination was included to know sunlight hours available in any lo- was obtained from the Secretary of Territory, Habitat and Dwelling cation. 4) An equation to measure the self-supply capacity for the study (MDMQ, 2012b) to delimit the CSCSM and it was contrasted with data area, which gives a focus to social characteristics and to food security in included in its especial development plan (MDMQ, 2014). Ortophotos social neighborhoods. on scale 1:5000 obtained from Agriculture Ministry (SIGTIERRAS, These modifications contribute a more domestic or residential 2016), satellite images gathered from Google™Earth were processed character, that although they bring urban agriculture closer to citizens, with ARCMAP 10.2 (ESRI, 2013). it represents a challenge in terms of the necessary infrastructure to be All rooftops were identified in the aforementioned two groups: 1) able to build a greenhouse on the roof; Both Sanjuan-Delmás et al. short-term feasibility and 2) medium and long-term feasibility (Fig. 5). (2018)and Sanyé-Mengual et al. (2015a, 2015b) point out the steel In CSCSM 3494 rooftops were found, from which 1160 were short-term structure of the greenhouse was the main contributor to environmental feasibility (33.2%). impact due to a large design that meets safety standards. In addition, Through digitalization each polygon surface was measured and the Piezer et al.(2019)indicates that the manufacturing process is the main total surface available for RTGs implementation was 7.70 ha (4.11 in consumer of fossil fuels and represents 69% of the net energy input; Area A and 3.59 in Area B). Most rooftops found were between 10 and and, it is necessary to carry out an analysis of the life cycle evaluating 90 m2 (76%) and only a small amount were between 170 and 250 m2 different alternatives of structures, both metallic and other materials, (3%) (Fig. 6). considering the height conditions of the houses, the complete life cycle Step 3: Production, self-sufficiency and self-supply. The data ob- of the material and the specific conditions of the local context. tained was studied along with results from the previous step for avail- In this line, Cerón-Palma et al. (2013) explored the implementation able surfaces in the studied area and analyzed in Eqs (1), (2) and (3). of rooftop greenhouses in homes of the Yucatan Peninsula in Mexico as Results showed that available surface for RTGs implementation, would a strategy to reduce energy consumption and GHG emissions, obtaining produce 789,750 kg of tomato in area A and 28,360 kg of lettuce in area savings of 391 kgCO2eq / year per house, in addition to offering en- B (Eq. (1)). This production would satisfy 145,408 and 50,642 in- vironmental, economic and social benefits, coinciding with the present habitants demand respectively, roughly 9 and 4.5% of Quito's popula- study. Regarding the environmental benefits that rooftop greenhouses tion (Eq. (2)). provide to residential neighborhoods, it is worth mentioning the de- As expected from results obtained for self-sufficiency, the required crease in indoor temperatures, as indicated by Peng and Jim (2013)and surface to achieve self-supply for CSCSM would be only 0.25 ha in area Doshi (2006), which in the case of cities with high temperatures turn A for tomato and 0.61 ha in area B for lettuce, which represented 3.25 out to be a strategy with great potential, as is the case of Quito. and 8.16% of available surface for short-term feasibility for RTGs im- Also, the culture of saving drinking water would be favored widely plementation, in each respective area (Eq. (3)). Afterwards, the surface in Latin America, since the system of cultivation of hydroponics allows 8 A. Nadal, et al. Urban Forestry & Urban Greening 44 (2019) 126389 Fig. 5. Characterization of covers in CSCSM. an efficient and quality use of water for irrigation, in addition to the the products, in order to guarantee that these are free of atmospheric greenhouses on the roof promote the collection of rainwater for the and aerobiological contaminants such as those made by (Amato- irrigation of crops. This would mean an economic saving and a lower Lourenco et al., 2016) and Ercilla-Montserrat et al. (2018, 2017), in the environmental impact than the use of drinking water, as Sanjuan- Mediterranean context. Another question to consider for 75% of the Delmás et al. (2018)and Farreny et al. (2011)points out. Finally, a roofs with medium or long-term potential is the fact of including the highlight of the presented methodology is the ability to adapt to dif- green roof strategy, since as Zhao et al. (2015) and Mohajerani et al. ferent contexts, through consultation with local sources of information, (2017) point out, this modification generates great thermal advantages information on weather conditions, local crops, among others; and in inside the homes, over all in cities with high temperatures like Quito. At this way serve as a basis for future interventions in cities around the the same time, one could also explore more complex and multi- world. functional systems such as rainwater harvesting or the use of photo- Potential of rooftops in Quito. voltaic cells to capture energy, creating a mosaic of productive rooftops The selected study area combined characteristics representative of as proposed by Toboso‐Chavero et al.(2018). both urban and periurban territories. It was useful to test the guidelines in both urban configurations (high building density, Area B) and peri- 5. Conclusions urban configuration (middle building density, area A). The results ob- tained using the guidelines validate their application, even though, This methodology has proven to be a promising and adaptable tool some further verification may be required in similar studies due to for identifying all rooftops with the potential for the implementation of differences in the quality of existing data with those of the chosen study RTGs with a social and residential perspective. The main strengths of area. the proposed methodology are based on the use of GIS and urban, Most rooftops had a surface between 10-90 m2 while the maximum agronomic and technical criteria; In addition to considering the demand surface was 250 m2. This important difference is remarkable, but the for food, the size of the population to calculate self-sufficiency and self- main criterion considered in this analysis, focused on a social neigh- supply in the short, medium and long term. However, field visits are borhood, was self-supply capacity rather than economic threshold. necessary for the confirmation of information. Medium and long-term feasibile rooftops are not considered, because in These guidelines can be useful for Latin American decision makers, the case of a social neighborhood extra expenses (constructions adap- researchers, students, communitarian organizations, schools, uni- tations) that would be caused to dwellers could prevent the RTGs im- versities and local governments among others. These parties could as- plementation to fulfil the chosen social approach. Only 33.2% of roof- sess their own RTGs initiatives adapting the guidelines to their goals. tops were short-term feasibility, a value much lower than the expected This would allow to create opportunities and to project the future of the one of 75%, which is the proportion of RC rooftops found in the cities with a self-supply perspective that would improve city resilience. neighborhood in the Ecuadorian census of 2010 (INEC, 2010). This For this research, in the study area there were found a total of 3.494 showed the importance of performing a research in neighborhood scale, rooftops, from which 1.160 (33.2%) were considered as short-term because results could vary from general statistics for city level. The feasibility. There were obtained a surface of 7.70 ha (around the 12% of results for self-supply showed that there is a potential to produce more the study area surface) of short-term feasibility rooftops. Regarding self- vegetables demanded in the neighborhood, which would allow to sufficiency and self-supply, study area would supply the 9% and 4.5% persue food security inside the neighborhood. of Quito's demand of tomato and lettuce; and in a neighborhood scale However, it would be necessary to carry out studies on the quality of 100% self-sufficiency and self-supply was obtained. The above supports 9 A. Nadal, et al. Urban Forestry & Urban Greening 44 (2019) 126389 Fig. 6. A.Ranges of short term available surfaces in CSCSM by ranges. B.Percentages of available surfaces per range for short term implementation of RTGs. Table 4 Potential Production and Self-Sufficiency for CSCSM short-term feasibility RTGs implementation. Area A (Tomato) Area B (Lettuce) Surface Ranges (m2) 10-90 90-170 170-250 10-90 90-170 170-250 Short-term available surface (ha) 2,16 1,64 0,32 2,14 1,23 0,22 “PR” Potential Production (kg/year) 413,900 315,000 60,700 16,91 9,75 1,70 7,895,700 28,36 “SS” Self-sufficiency (Inhabitant) 76226 58011 11170 30194 17415 3033 145408 50642 Note: Tomato performance is 192,000 kg/ha/year (AIC, 2003),lettuce performance is 7900 kg/ha/year (Rendón and Ledesma,2012), demand of tomato is 543 kg/ person/year, and of lettuce is 056 kg/person/year (this is consider for an adult consume, the only data available) (MAGAP, 2016). the effectiveness and potential use of the proposed methodology. This future work, the present study opens the door to new lines of research methodology also provides the opportunity to provide a new character in the field of urban food systems; it is necessary to study the impact and activity to the roofs and the unfinished houses, taking advantage of and feasibility of using different local substrates for the production of it effectively and providing a real and efficient alternative for the re- horticultural crops on the roofs, as well as the analysis of various ma- sidual and unused spaces, such as a large part of the roofs in Quito. terials for the structure of the greenhouses; and at the food level, it In addition to the direct benefits at the level of nutrition derived would be interesting to evaluate the quality of the products produced from the cultivation in the roofs, the benefits at environmental and by protected (with greenhouses) and unprotected (without green- urban level that can be generated can also be considered. Regarding houses) crops in urban areas. 10 A. Nadal, et al. Urban Forestry & Urban Greening 44 (2019) 126389 Table 5 Competitiveness (MINECO) for the financial support for the research Required surface for self-supply of CSCSM. project “Agrourban sustainability through rooftop greenhouses. Eco- Self-Supply required area (ha) innovation on residual flows of energy, water and CO2 for food pro- duction” (CTM2013-47067-C2-1-R) (MINECO/ FEDER, UE) and the Vegetable Tomato % Lettuce % research project “Integrated rooftop greenhouses: a symbiosis of en- ergy, water and CO2 emissions for buildings. Towards urban food se- "SPA" (ha) 0,25 0,63 Short-term available surface by 10-90 4,3 5,83 14,61 curity in a circular economy” CTM2016-75772-C3-1-2-3 R) (MINECO/ ranges (ha) 90-170 2,87 8,73 7,19 FEDER, UE). The authors also acknowledge financial support from the 170-250 0,54 46,41 100* Spanish Ministry of Economy and Competitiveness through the “María Percentage needed of Total 3,25 8,16 de Maeztu” program for Units of Excellence in R&D (MDM-2015-0552), available surface the National Council for Science and Technology of Mexico Note: Population CSCSM: 8862 inhabitants; "SPA" Self-supply required area, (CONACYT), the Council for Science, Innovation and Technology of Short-term available surface by ranges: 7,7 ha. State of Yucatán (CONCIYTEY) for awarding a research scholarship to * Characterized area is lower than required area. Ana Nadal (CV376044), and to the Ecuadorian Secretary for Science and Technology (SENESCYT) for the scholarship granted to D. Rodriguez in Convocatoria Abierta 2015 s phase. Acknowledgments The authors thank the Spanish Ministry of Economy and Appendix A. Main characteristics of Quito metropolitan district Characteristic Value Reference Altitude range 1200-4000 mamsl EPM-METROQUITO, 2012, MDMQ, 2012a, 2012 Precipitation in dry season (June to September) 202 to 27 mm/month (INAMHI, 2015) Precipitation in rainy season (October to May) 1262 to 1622 mm/month INAMHI, 2015 Climate zones 15 (Holdridge map) EPM-METROQUITO, 2012 Temperature range (-4 C to 22 °C) INAMHI, 2015 Average temperature in the urban area 16 °C MDMQ, 2012a, 2012 Urban population 1,6 millions INEC, 2010 Annual growth index 1,5% INEC, 2010 Population density 92 inhabitants/ha INEC, 2010 Rooftop composition 75, 32% reinforced concrete 2468% others INEC, 2010 Appendix B. Socio-economic indicators of the study area Indicator Value Reference Population 8862 inhabitants INEC, 2010; MDMQ, 2011 Surface 63.29 ha INEC, 2010; MDMQ, 2011 Housing built 3,490 INEC, 2010; MDMQ, 2011 Population density 110.5 inhabitants/ha INEC, 2010; MDMQ, 2011 Population men 4,273 inhabitants INEC, 2010; MDMQ, 2011 Population women 4,589 inhabitants INEC, 2010; MDMQ, 2011 Population under 5 years 366 inhabitants INEC, 2010; MDMQ, 2011 Economically active population 6,080 inhabitants INEC, 2010; MDMQ, 2011 Unemployment rate 3.8% Larrea, 2009 Chronically undernourished children 32.4% - 35.3% Larrea, 2009 References Cerón-Palma, I., Sanyé-Mengual, E., Oliver-Solà, J., Montero, J.-I., Rieradevall, J., 2012. Barriers and opportunities regarding the implementation of Rooftop Eco.GReenhouses (RTEG) in Mediterranean cities of Europe. J. Urban Technol. 19, AGROCALIDAD, 2015. Resolución Técnica N - 0105. Guía de buenas práctivas agrícolas 1–17. https://doi.org/10.1080/10630732.2012.717685. para tomate riñón. Cerón-Palma, I., Sanyé-Mengual, E., Oliver-Solà, J., Montero, J.I., Ponce-Caballero, C., AGROCALIDAD, 2013. Resolución DAJ-2013465-0201.0226 Manual de Procedimiento Rieradevall, J., 2013. Towards a green sustainable strategy for social neighbourhoods para la Certificación de Unidades de Producción de Buenas Prácticas Agrícolas in Latin America: Case from social housing in Merida, Yucatan, Mexico. Habitat Int. Generales. 38, 47–56. https://doi.org/10.1016/j.habitatint.2012.09.008. AIC, 2003. El Cultivo De Tomate Rinon En Invernadero Lycopersicum Esculentum. Chavoya, I., García, J., Rendón, H., 2009. Una reflexión sobre el modelo urbano: ciudad Asociacion de Indígenas del Cañar, Quito, Ecuador. dispersa-ciudad compacta. SCTV Barcelona. pp. 37–50. Amato-Lourenco, L.F., Moreira, T.C.L., De Oliveira Souza, V.C., Barbosa, F., Saiki, M., Clavijo, C., 2013. La agricultura urbana en Quito: análisis de la sustentabilidad de las Saldiva, P.H.N., Mauad, T., 2016. The influence of atmospheric particles on the huertas de tres proyectos. elemental content of vegetables in urban gardens of Sao Paulo, Brazil. Environ. Colinas, J., Bush, P., Manaugh, K., 2018. The Socio-Environmental Impacts of Public Pollut. 216, 125–134. https://doi.org/10.1016/j.envpol.2016.05.036. Urban Fruit Trees: A Montreal Case-study. Urban For. Urban Greenhttps://doi.org/ Baker, L., 2000. Warehouse supports Urban agriculture. Bussiness, vol. 22. pp. 16–18. 10.1016/j.ufug.2018.05.002. Baudoin, W., Nono-Womdim, R., Lutaladio, N., Hodder, A., Castilla, N., Leonardi, C., De CONQUITO, 2009. La ciudad viva como URBS, Agencia Municipal de Desarrollo Pascale, S., Qaryouti, M., 2013. Good Agricultural Practices for Greenhouse Económico - CONQUITO. Congreso Internacional: La Ciudad Viva Como URBS. Vegetable Crops: Principles for Mediterranean Climate Areas. Food and Agriculture Agricultura Urbana Participativa AGRUPAR - Quito, Ecuador, pp. 1–9. Organization of the United Nations. Correa, F., 2012. Una linea en los Andes. GSD-Harvard, Cambridge. Carrión, F., Erazo, J., 2012. La forma urbana de Quito: una historia de centros y periferias. Cruz, M.C., Sánchez-Medina, R., 2003. Agriculture in the City. A Key to Sustainability in Bull. l’Institut français d’études Andin. 503–522. https://doi.org/10.4000/bifea.361. Havana, Cuba, Idrc. 11 A. Nadal, et al. Urban Forestry & Urban Greening 44 (2019) 126389 De la Sota, C., Ruffato-Ferreira, V.J., Ruiz-García, L., Alvarez, S., 2018. Urban Green Development of a building-integrated roof top greenhouse in Barcelona, Spain. Acta Infrastructure As a Strategy of Climate Change Mitigation. A Case Study in Northern Hortic. https://doi.org/10.17660/ActaHortic.2017.1170.107. Spain. Urban For. Urban Greenhttps://doi.org/10.1016/j.ufug.2018.09.004. Moran-Alonso, N., 2011. Huertos urbanos en tres ciudades europeas: Londres, Berlín, Despommier, D., 2011. The vertical farm. HortScience. Madrid. Boletín CF+ S 2008–2009. https://doi.org/1578-097X. Doshi, H., 2006. Environmental benefits of Green roofs on a City scale—an example of Moran-Alonso, N., Hernandez, A., 2011. Historia de los huertos urbanos. De los huertos City of Toronto. 4th North American Green Roof Conference: Greening Rooftops for pobres a los programas de agircultura urbana ecoló gica, Programas De Agricultura Sustainable Communities. Urbana Ecológica, Madrid. Dubbeling, M., Massonneau, E., 2014. Rooftop agriculture in the context of climate Nadal, A., Alamús, R., Pipia, L., Ruiz, A., Corbera, J., Cuerva, E., Rieradevall, J., Josa, A., change. Appropriate Technology 41 (3), 48–52. 2017a. Urban planning and agriculture. Methodology for assessing rooftop green- Duenas, A.R., 2010. Promoting value chains in urban agriculture for local development in house potential of non-residential areas using airborne sensors. Sci. Total Environ. Quito. Urban Agric. Mag. 61–62. 601–602. https://doi.org/10.1016/j.scitotenv.2017.03.214. Empresa Pública Metropolitana METRO QUITO, 2012. Estudio de Impacto Ambiental de Nadal, A., Cerón-Palma, I., García-Gómez, C., Pérez-Sánchez, M., Rodríguez-Labajos, B., la Primera Línea del Metro de Quito. 322. Cuerva, E., Josa, A., Rieradevall, J., 2018. Social perception of urban agriculture in Ercilla-Montserrat, M., Izquierdo, R., Belmonte, J., Montero, J.I., Muñoz, P., De Linares, Latin-America. A case study in Mexican social housing. Land Use Policy. https://doi. C., Rieradevall, J., 2017. Building-integrated agriculture: A first assessment of aero- org/10.1016/j.landusepol.2018.02.055. biological air quality in rooftop greenhouses (i-RTGs). Sci. Total Environ. https://doi. Nadal, A., Cerón, I., Cuerva, E., Gabarrell, X., Josa, A., Pons, O., Sanyé, E., Rieradevall, J., org/10.1016/j.scitotenv.2017.04.099. 2015. Urban agriculture in the framework of sustainable urbanism. Temes de disseny Ercilla-Montserrat, M., Muñoz, P., Montero, J.I., Gabarrell, X., Rieradevall, J., 2018. A 0, 92–103. study on air quality and heavy metals content of urban food produced in a Nadal, A., Llorach-Massana, P., Cuerva, E., López-Capel, E., Montero, J.I., Josa, A., Mediterranean city (Barcelona). J. Clean. Prod. https://doi.org/10.1016/j.jclepro. Rieradevall, J., Royapoor, M., 2017. Building-integrated rooftop greenhouses: an 2018.05.183. energy and environmental assessment in the mediterranean context. Appl. Energy ESRI, 2013. ARCMAP 10.2. 187, 338–351. https://doi.org/10.1016/j.apenergy.2016.11.051. FAO, 2014a. City Region Food Systems: Sustainable Food Syst Ems and Urbanization. Nadal, A., Llorach-Massana, P., Cuerva, E., López-Capel, E., Montero, J.I., Josa, A., FAO, 2014b. Ciudades más verdes en América Latina y el Caribe. Un informe de la FAO Rieradevall, J., Royapoor, M., 2017b. Building-integrated rooftop greenhouses: an sobre la agricultura urbana y periurbana en la región, Roma, Italia. energy and environmental assessment in the mediterranean context. Appl. Energy FAO, 2012. Agricultura Urbana y periurbana en América Latina y El Caribe : una realidad. 187. https://doi.org/10.1016/j.apenergy.2016.11.051. Roma, Italia. . Nastran, M., Kobal, M., Eler, K., 2019. Urban heat islands in relation to green land use in FAO, 2005. Los Medios de vida Crecen en los Huertos. Roma, Italia. . European cities. Urban For. Urban Green. https://doi.org/10.1016/j.ufug.2018.01. Farreny, R., Morales-Pinzón, T., Guisasola, A., Tayà, C., Rieradevall, J., Gabarrell, X., 008. 2011. Roof selection for rainwater harvesting: quantity and quality assessments in Nieto, M., 1999. Metodología de evaluación de proyectos de viviendas sociales. Spain. Water Res. 45, 3245–3254. https://doi.org/10.1016/j.watres.2011.03.036. NU. CEPAL, 2013. Estrategias de desarrollo bajo en carbono en megaciudades de América Figueroa, J.A., 2012. Nono Movilización Política y migración campesina, 1st ed. Latina. Santiago, Chile. . Municipio del Distrito Metropolitano de Quito, Quito, Ecuador. Orsini, F., Gasperi, D., Marchetti, L., Piovene, C., Draghetti, S., Ramazzotti, S., Bazzocchi, Garza, N., 2009. Urban economic-environmental dilemas in Latin American cities Néstor G., Gianquinto, G., 2014. Exploring the production capacity of rooftop gardens Garza. Investig. y Desarro. 17, 288–328. (RTGs) in urban agriculture: the potential impact on food and nutrition security, Germer, J., Sauerborn, J., Asch, F., de Boer, J., Schreiber, J., Weber, G., Müller, J., 2011. biodiversity and other ecosystem services in the city of Bologna. Food Secur. 6, Skyfarming an ecological innovation to enhance global food security. J. Fur 781–792. https://doi.org/10.1007/s12571-014-0389-6. Verbraucherschutz und Leb. 6, 237–251. https://doi.org/10.1007/s00003-011- Orsini, F., Kahane, R., Nono-Womdim, R., Gianquinto, G., 2013. Urban agriculture in the 0691-6. developing world: a review. Agron. Sustain. Dev. https://doi.org/10.1007/s13593- Gilbert, A., 2011. La vivienda en américa latina: revisando estrategias. Rev. Ing. 013-0143-z. Halloran, A., 2011. Incorporating Urban Agriculture Into Urban Planning : the Tale of Peng, L.L.H., Jim, C.Y., 2013. Green-roof effects on neighborhood microclimate and Three Cities. Copenhagen, Denmark. . human thermal sensation. Energies 6, 598–618. https://doi.org/10.3390/ Hou, J., Grohmann, D., 2018. Integrating community gardens into urban parks: lessons in en6020598. planning, design and partnership from Seattle. Urban For. Urban Green. https://doi. Piezer, K., Petit-Boix, A., Sanjuan-Delmás, D., Briese, E., Celik, I., Rieradevall, J., org/10.1016/j.ufug.2018.05.007. Gabarrell, X., Josa, A., Apul, D., 2019. Ecological network analysis of growing to- INAMHI, 2015a. Boletín climatológico Semestral 2015 - 001 - Instituto de Meteorología e matoes in an urban rooftop greenhouse. Sci. Total Environ. https://doi.org/10.1016/ Hidrología. Quito, Ecuador. . j.scitotenv.2018.09.293. INAMHI, I.D.M.E.H., 2015b. Boletín climatológico SEMESTRAL 1015. Vol. 01. Pons, O., Nadal, A., Sanyé-Mengual, E., Llorach-Massana, P., Cuerva, E., Sanjuan-Delmás, INEC, 2010. Sistema Integrado de Consultas (REDATAM) - Instituto Naciona de D., Muñoz, P., Oliver-Solá, J., Planas, C., Rovira, M.R., 2015. Roofs of the future: Estadísticas y Censos del Ecuador [WWW Document]. VII Censo Población y VI vi- rooftop greenhouses to improve buildings metabolism. Procedia Engineering vienda. 441–448. https://doi.org/10.1016/j.proeng.2015.10.084. INEN, 2011. NTE INEN 1334-1:2011 Rotulado de productos alimenticios para consumo Quintero, M., Gómez, L., 2012. ciudades difusas a ciudades compactas. Provincia 27, humano. Parte 1. Requisitos. 43–76. INEN, 1996. NTE INEN 2 104:1996 Hortalizas frescas. Definiciones y Clasificación. Rendón, V., Yance, M., 2012. Establecimiento del cultivo hidropónico de Lechuga Jaramillo, E., Van Sluys, C., 2012. Repensar el proyecto urbano residencial en la ciudad (Lactuca sativa L.) variedad Great Lakes 188, mediante la utilización de diferentes lineal: Un estudio urbano arquitectonico sobre la vivienda sustentable en el distrito tipos de sustratos sólidos en la zona de Babahoyo. Universidad Técnica de metropolitano de Quito. I Congreso Internacional de Vivienda Colectiva Sostenible, Babahoyohttps://doi.org/10.1017/CBO9781107415324.004. Barcelona, 25, 26 y 27 de Febrero de 2014. pp. 354–359. Rojas, E., 2016. Housing policies and Urban development: lessons from the latin Jeavons, J., Cox, C., 2007. El huerto sustentable, como obtener suelos saludables, pro- American experience 1960-2010. Land and the City. p. 429. ductos sanos y abundantes. Universidad de California. RUAF Foundation, 2015. City Region Food Systems. Urban Agric. Mag. Larrea, C., Larrea, A.I., Andrade, D., 2009. Atlas Social Para Quito Urbano. Sanjuan-Delmás, D., Llorach-Massana, P., Nadal, A., Ercilla-Montserrat, M., Muñoz, P., La Rosa, D., Barbarossa, L., Privitera, R., Martinico, F., 2014. Agriculture and the city: a Montero, J.I., Josa, A., Gabarrell, X., Rieradevall, J., 2018. Environmental assessment method for sustainable planning of new forms of agriculture in urban contexts. Land of an integrated rooftop greenhouse for food production in cities. J. Clean. Prod. 177, Use Policy 41, 290–303. https://doi.org/10.1016/j.landusepol.2014.06.014. 326–337. https://doi.org/10.1016/j.jclepro.2017.12.147. MAGAP, 2016. Sistema de Informacion Nacional del Ministerio de Agricultura Ganaderia Sanyé-Mengual, E., Cerón-Palma, I., Oliver-Solà, J., Montero, J.I., Rieradevall, J., 2015a. y Pesca del Ecuador [WWW Document]. Integrating horticulture into cities: a guide for assessing the implementation potential Maxwell, D., 2000. Urban Livelihoods and Food and Nutrition Security in Greater Accra, of rooftop greenhouses (RTGs) in industrial and logistics parks. J. Urban Technol. 22, Ghana, Research Report 112. International Food Policy Research Institute in colla- 87–111. https://doi.org/10.1080/10630732.2014.942095. boration with Noguchi Memorial Institute for Medical Research and the World Health Sanyé-Mengual, E., Oliver-Solà, J., Montero, J.I., Rieradevall, J., 2015b. An environ- Organization, Washington, D.C 2000, pp. xiv, 172. mental and economic life cycle assessment of rooftop greenhouse (RTG) im- Maxwell, D., Larbi, W.O., Lamptey, G.M., Zakariah, S., Armar-Klemesu, M., 1999. plementation in Barcelona, Spain. Assessing new forms of urban agriculture from the Farming in the shadow of the city: changes in land rights and livelihoods in peri- greenhouse structure to the final product level. Int. J. Life Cycle Assess. 20, 350–366. urban Accra. Third World Plann. Rev. 21, 373–392. https://doi.org/10.1007/s11367-014-0836-9. MDMQ, 2014. Ordenanza Municipal 0024: Plan Especial De Desarrollo Territorial Schneider, A., Woodcock, C.E., 2008. Compact, dispersed, fragmented, extensive? A Comuna Santa Clara De San Millán - Distrito Metropolitano De Quito. comparison of urban growth in twenty-five global cities using remotely sensed data, MDMQ, 2012a. Plan Metropolitano de Ordenamiento Territorial - Municipio del Distrito pattern metrics and census information. Urban Stud. https://doi.org/10.1177/ Metropolitano de Quito. 0042098007087340. MDMQ, 2012b. Secretaria de Territorio Habitat y Vivienda - Municipio del Distrito SENPLADES, 2013. Plan Nacional Buen Vivir 2013-2017. Secretaría Nacional de Metropolitano de Quito [WWW Document]. Planificación y Desarrollo. MDMQ, 2011. Reglas Técnicas de Arquitectura y Urbanismo (Anexo de la Oordenanza SIGTIERRAS, 2016. Fotografía Area y Ortofotos. [WWW Document]. . Municipal 172 Del Régimen Administrativo del Suelo) - Municipio del Distrito Tian, Y., Jim, C.Y., Tao, Y., 2012. Challenges and strategies for greening the compact city Metropolitano de Quito. of Hong Kong. J. Urban Plan. Dev. https://doi.org/10.1061/(ASCE)UP.1943-5444. Mohajerani, A., Bakaric, J., Jeffrey-Bailey, T., 2017. The urban heat island effect, its 0000076. causes, and mitigation, with reference to the thermal properties of asphalt concrete. Toboso‐Chavero, S., Nadal, A., Petit‐Boix, A., Pons, O., Villalba, G., Gabarrell, X., Josa, A., J. Environ. Manage. https://doi.org/10.1016/j.jenvman.2017.03.095. Rieradevall, J., 2018. Towards productive cities: environmental assessment of the Montero, J.I., Muñoz, P., Llorach, P., Nadal, A., Sanyé-Mengual, E., Rieradevall, J., 2017. food‐energy‐Water Nexus of the urban roof mosaic. J. Ind. Ecol. 22, 14. https://doi. 12 A. Nadal, et al. Urban Forestry & Urban Greening 44 (2019) 126389 org/10.1111/jiec.12829. Fox, E., Bignet, V., Troell, M., Lindahl, T., Singh, S., Cornell, S.E., Srinath Reddy, K., Vaca, F., 2015. El perfil vertical. Plan V Miradas. Narain, S., Nishtar, S., Murray, C.J.L., 2019. Food in the Anthropocene: the Wadel, G., Avellaneda, A., Cuchí, A., 2010. Sustainability in industrialised architecture: EAT–lancet Commission on healthy diets from sustainable food systems. Lancet. closing the materials cycle [La sostenibilidad en la arquitectura industrializada: https://doi.org/10.1016/S0140-6736(18)31788-4. cerrando el ciclo de los materiales]. Inf. la Constr. 62, 37–51. https://doi.org/10. Zezza, A., Tasciotti, L., 2010. Urban agriculture, poverty, and food security: empirical 3989/ic.09.067. evidence from a sample of developing countries. Food Policy 35, 265–273. https:// Willett, W., Rockström, J., Loken, B., Springmann, M., Lang, T., Vermeulen, S., Garnett, doi.org/10.1016/j.foodpol.2010.04.007. T., Tilman, D., DeClerck, F., Wood, A., Jonell, M., Clark, M., Gordon, L.J., Fanzo, J., Zhao, Q., Myint, S.W., Wentz, E.A., Fan, C., 2015. Rooftop surface temperature analysis in Hawkes, C., Zurayk, R., Rivera, J.A., De Vries, W., Majele Sibanda, L., Afshin, A., an Urban residential environment. Remote Sens. (Basel) 7, 12135–12159. https:// Chaudhary, A., Herrero, M., Agustina, R., Branca, F., Lartey, A., Fan, S., Crona, B., doi.org/10.3390/rs70912135. 13