1. Introduction
In recent years, the idea of green cities has been proposed for the sustainability of urban environments and, as the essence of sustainable urban development, has placed a lot of emphasis on the need to pay attention to the environmental status of cities and the communities’ duties towards future generations [
1,
2,
3,
4]. Green and sustainable cities have clean air, clean water, and clean streets. They also encourage green behavior, such as the use of public transport, and their environmental degradation is relatively low [
5,
6]. One of the most important factors affecting the sustainability of cities is their management in the field of agriculture. In fact, agriculture is one of the most important economic sectors and recognized as one of the foundations for the food security of societies. Unfortunately, mismanagement in this area has had devastating consequences, such as reduced production, increased demand, and severe climate change, and caused food crises in many parts of the world [
7,
8]. In a general view, if the city is being divided into two parts, which consists of its main body and structure and its citizens, it will be determined that the development of the city’s body is worthless regardless of the needs and conditions of the citizens. The first human need after air and water is food and today, agricultural production is in difficulty due to the growing population and the shortage of water resources in the world. With the same philosophy and system they used in previous years, farmers cannot meet the needs of today’s world in general and of developing countries in particular. Therefore, based on the character of postmodern philosophy, today’s world is a combination of tradition, and modernity and agriculture in the current world also need to be revised [
9]. The overtaking of urban population from the population of villages and the ever-increasing urbanization has changed agricultural practices, one of the most important of which is the forms and methods of urban agriculture [
10]. Urban agriculture occurs wherever humans can grow grains even in the smallest part of the soil [
11]. This is not only the place of urban agriculture that separates it from traditional and rural agriculture, but more importantly, it is the interactions and coping with an urban ecosystem [
12]. Agricultural production in the city does not mean agriculture and cultivation in its general form, but it refers to easy planting and producing microfood products with minimal facilities. Urban agriculture not only generates food supplies in cities but also addresses problems such as poverty, malnutrition, and environmental degradation and provides food security [
13,
14], while providing many business opportunities for small and medium-sized entrepreneurs [
15]. Urban agriculture supports sustainable development goals, including environmental protection, health and nutrition, poverty reduction, building community capabilities, participatory decision making, and economic development of society, and is known as an agile network in pushing and directing citizens towards knowledge and solutions [
16]. In other words, today, urban agriculture development can have at least two basic roles: It initially provides food security for urban communities and, in the second step, it will reduce the burden of food supply that affects rural communities.
Activities related to the urban agriculture approach are generally classified in the two groups of uncontrolled environments and controlled environments. Both approaches have been formed to reduce poverty and hunger, create sustainable patterns in the production of food products in pursuit of sustainable development goals, and preserve environmental values [
17]. Agriculture in uncontrolled environments refers to any open-air urban agriculture operations and means that there is no control over the environmental conditions and factors affecting the growth of food products in this kind of agriculture [
18]. Of the various types of methods for implementing this type of urban agriculture, one can mention the local gardens and farms, green and violet walls outside the buildings, and green roofs. With the expansion of the competitive sector of agricultural industry and the importance of the lack of fertile and cultivated land and, consequently, the reduction of high-quality products, exploiting unused surfaces such as roofs is considered to be one of the most effective methods for improving agricultural production [
19]. Williams et al. (2010) concluded that the government’s emphasis on creating green roofs in Australian cities is due to the environmental benefits it contains. While the two intensive and extensive types of green roofs are globally recognized, a small number of extensive green roofs have been made in Australia. One of the major obstacles for increasing the widespread use of extensive green roofs (also referred as ecoroofs) in Australia was considered to be the lack of information to evaluate their use in local conditions [
20].
Farming in controlled environments is a form of agriculture in which environmental conditions such as light, temperature, humidity, and nutrient cycles are being controlled and associated with urban agriculture and green constructions [
21]. Agricultural practices in controlled environments include various types of greenhouses, building farms, and vertical farms. According to the general definition, vertical agriculture refers to the cultivation of plants and even animals inside skyscrapers and high-rise towers or inclined highs in which there is a hydroponic farming system to create synergies between the environment within the building and the agricultural operations, such as multiple plantations in the floors or glass space in front of the buildings [
22]. Vertical farming can be defined as a system in which plants, animals, fungi, and other living creatures contribute to the food supply and produce food, fuel, fiber or other products, and they continue to work in a vertical state on each other [
23]. Furthermore, the agricultural system in buildings has progressed dramatically over the last 10 years through the use of new technologies, including nonsoil agriculture (hydroponics), aeroponic systems, and drip irrigation systems [
24]. One of the most important goals of constructing these vertical farms is to preserve the natural environment, enjoy sufficient food, and cultivate healthy and organic food, which can make significant contributions to the sustainability of communities.
At present, urban agriculture is a small, indigenous world that has more to do with food growth and using innovative ideas to generate income in a limited area of land and putting emphasis on direct and non-intermediary purchases [
25]; it has become a huge economic force and improved social awareness on issues such as hunger, poverty, and health. In fact, urban agriculture, with proper use of the resources and natural habitat of a city, provides part of the nutritional needs of citizens [
26] and leads to environmental and ecological benefits and prevents the destruction of natural resources. It can also increase agrotourism in cases where conditions such as agricultural landscape, accessibility, supporting infrastructure, and public acceptance are available [
27], where farmers develop their service by offering food and selling fresh agricultural products to urban tourists. This leads to economic investment and creates new employment opportunities in order to step towards the social and economic dimensions of sustainable development. In this regard, this study aims to examine the extent to which cities are committed to implementing urban agriculture development policies by considering the dimensions affecting it in eight major cities of Iran.
The rest of this paper is structured as follows.
Section 2 presents an overview of the dimensions being considered for urban agriculture in Iran. In
Section 3, a review of the pertinent preliminaries and research methods, such as the best–worst method, weighted aggregated sum product assessment, and the proposed BWM–WASPAS approach, are explained.
Section 4 presents a data analysis case of evaluating and prioritizing eight populous cities of Iran in order to determine how much they adhere to the urban agriculture policies for sustainable development. Finally,
Section 5 summarizes the main conclusions.
4. Results and Discussion
In this research, eight cities of Iran with a population of more than a million (Tehran
A1, Mashhad
A2, Isfahan
A3, Karaj
A4, Shiraz
A5, Tabriz
A6, Ahwaz
A7, and Qom
A8) were evaluated and prioritized by considering the opinions of four experts
from Iran’s Ministry of Agriculture with respect to the five attributes (environmental
C1, socioeconomic
C2, vulnerable members empowerment
C3, training and culturizing
C4, and supply
C5). The experts of the decision-making team determined the best (most important) and worst (least important) attributes among the five attributes of the research. In this vein, given their experience and cognition of the government’s macro policies, they selected the socioeconomic dimension as the most important dimension due to its vast impact on improving the economic indexes, social situations, and employment, and also, the supply dimension was selected as the least important dimension. Then, the preference vector of the best attribute (socio-economic dimension) over the other attributes and the preference vector of the other attributes over the worst attribute (supply dimension) were obtained. It should be noted that these preferences were formed using a 9-point scale (from 1 to 9 due to their importance).
Figure 3 demonstrates the final decision of the experts’ team in this regard.
Then, using the preferences obtained from the experts and applying Equations (1) and (2), the following model was created to calculate the weight associated with each of the attributes.
After that, by implementing the abovementioned model in the
Lingo software, the optimal values of
and
were computed, the results of which are shown in
Table 2.
Based on the BWM decision approach, the more consistency ratios are closer to zero, the more consistent results also are [
45], and getting CR values less than 0.25 shows a high degree of consistency and reliability [
54]. In this model, given that the value of
is equal to 9, its corresponding consistency index according to
Table 1 is 5.23, and by plugging in this value and the obtained value of
(1.2583) in Equation (3), the consistency ratio was calculated. As 0.2405 is less than 0.25, this indicates the high reliability and accuracy of the achieved weights. Subsequently, decision-making team members were asked to assign a score to each city by considering each of the attributes based on a 9-point scale (from very bad as 1 to very good as 9). The result of this scoring was obtaining the decision-making matrix, based on averaging the opinions of the experts, which is shown as
Table 3.
Then, the decision matrix was normalized in
Table 4.
After that, by having the weights of the attributes and the normalized decision matrix and using Equation (10), the variance values were calculated, as demonstrated in
Table 5.
Then, as demonstrated in
Table 6, the values of
and
were also calculated by Equations (8) and (9).
Finally, by computing the values of
using Equation (7) and obtaining the values of
using Equation (6), the final ranking of alternatives is as shown in
Table 7.
It is obvious that the closer the value of is to 1, the greater the adherence it suggests to the urban agriculture policies by the cities. Based on the obtained rankings, the cities of Tabriz, Shiraz, and Tehran have the highest adherence to the implementation of urban agriculture policies. This means that, compared to the other cities studied, they have a better situation in terms of availability of existing cultural infrastructures for implementing urban agriculture and, despite the ambiguity of urban policies in this field, which are only limited to some general sentences on the paper, these cities are trying to synchronize themselves with this growing global trend that can save humanity and provide food security to cities, especially for the next generations. However, due to various international indexes, it should be noted that despite their high rankings in this evaluation system, the situation of these cities is still not satisfactory, and they are far from the international standards of urban agriculture and stepping towards sustainable development of the community. In order to solve this problem and fill the gap between the country’s situation and international progress in this area, it is suggested that in addition to reforming the macro policies in the field of agriculture and promoting seriousness in the implementation of urban agriculture by authorities, the use of modern urban agriculture development methods must be put into action. One of these new approaches, which can contribute to the promotion of sustainable urban agriculture, is the proliferation of vertical farms in the cities. According to forecasts, the population of Iran will reach 100 million by the year 2022, which will reduce the average per capita available water resources. Therefore, using vertical farms can be very helpful for providing water and food requirements of this population, which uses modern irrigation methods in its production process.
By expanding the urban areas and energy consuming sectors in the country, energy consumption in all sectors (transportation, residential, commercial, industrial, and agricultural) has been increased and consequently, greenhouse emissions and air pollution have had a great impact on the health of the citizens. One of the ways that can be used to develop urban agriculture in major cities is vertical farming. Using this approach with regard to its benefits in removing fossil fuel consumption and producing food within buildings and under controlled conditions will reduce the amount of environmental pollution caused by agricultural activities. Furthermore, it has been found that the development and spatial distribution of cities and lack of proper planning for land use has destroyed the aesthetic aspects of cities and reduced the relationship between citizens and nature. In order to solve this problem, vertical farms can play an important role in increasing the level of greenness and establishing a link between residents and nature. With regard to the compact construction in urban spaces and reducing the amount of attention to the physical and psychological needs of the citizens, especially elderly people, building such farms in buildings can play an important role in increasing the amount of social interactions and creation of communal spaces. Indeed, rewriting old policies and updating them and taking into account the issues that citizens are dealing with can be a major step towards promoting the country in the field of food security.
It should be noted that Iran is naturally dealing with water scarcity due to its climatic and geographical conditions. Due to the lack of up-to-date agricultural strategies and the excessive use of aquifers and the lack of proper educational programs for residents of different regions about the water crisis and proper management of water consumption, the crisis is on the rise day by day. It is obvious that this crisis affects agriculture and as a result, it also overshadows food security. Therefore, adopting a method that can be used to meet the food needs of citizens, regardless of the climate, can be very crucial for the country. Moreover, parts of the Iranian society are now aging, and this aging process is expanding rapidly. As an example, this phenomenon is seen in the agricultural sector’s workforce and this is while the agricultural sector, in addition to this challenge, is also facing frustrated agricultural students. Therefore, despite the increasing number of graduates in this field, there is still a lack of skilled human resources in the country’s agricultural sector. Thus, by preparing the possibility of working for these specialists by building vertical farms and creating a favorable biological environment in the community, it would be possible to influence the rate of improvement and economic growth in the cities of Iran.
5. Conclusions
Although urban agriculture is recognized as an emerging phenomenon in the process of sustainable urban development, due to the necessities mentioned in this research, it plays an important role in the future of urban planning and design. Designing productive cities and producing indigenous food industries is not a periodic approach, but it is considered as a central policy in the urban planning process. Meanwhile, the promotion of urban agriculture is one of the necessary strategies to stabilize this kind of development. The natural conditions of Iran and the severe water and soil constraints require a far greater perspective in the maintenance of agricultural lands than the experiences in developed countries. In urban agriculture, it should be noted that, firstly, the areas of urban agriculture are limited and largely unique. Secondly, urban gardens are a national wealth and belong to all people in society and in a sustainable way; future generations must safely take this precious heritage from us and should not be prevented from enjoying such delightful spaces.
Therefore, according to the characteristics of each city, various urban development patterns should be used to preserve agricultural lands and organize them. For example, in cities such as Qom and Ahwaz, which are facing water scarcity, agricultural policies need to be designed in ways that require less water. Furthermore, the policies that are being adopted should take into account the particular weather conditions of each city and encourage the development of plants that can grow in the weather of that particular region. Given to the rapid growth of cities and population in recent decades and the destruction of agricultural lands and gardens around cities, a need for more planning to control unbridled urban growth and provide food security for all citizens, especially in underdeveloped countries, is highly felt. The cities of Iran have also grown over the last few decades, and many of them were uncontrolled and out of place. This issue, coupled with an ever-increasing population, can create many problems in providing food for residents of large cities and keeping the urban air and environment clear. In fact, it can be stated that understanding factors such as food security, quality of living spaces, energy consumption, etc., as the critical issues of the region and prioritizing them according to their local significance can help the country’s agricultural policies towards sustainable development to be updated. Although the country is far behind with the development of urban agriculture, it is never too late to reform the policies and remedy the shortcomings.