عنوان مقاله [English]
It was estimated that, by 2050, the world's population would be around 9 billion, of which two thirds would live in cities. Due to this increase in urban population, there should be a detailed comprehensive plan for food security and food supply for this growing population. In response to this need, urban and agriculture planners introduce a kind of farming called "urban agriculture." The purpose of creating agriculture in the city is to plant and produce micro-food products with easy and minimal facilities. One of the challenges of urban agriculture is that urban agriculture is traditionally neglected in urban planning. The urban agriculture, for many urban planners, remains a rural activity that has entered the city with urbanization and is just a nuisance. Urban agriculture can be expressed in two vertical and horizontal spaces. Accordingly, the purpose of this paper was to explore the potential of urban agriculture horizontally in the 5th district of Tehran municipality. The benefits of urban agriculture include organizing community development, improving land consolidation, reduction in the family budget, improving the quality of the climate, social cohesion, economic development, and protection of the green space.
The 5th district of Tehran municipality has a total area of 54136 hectares in the northwest of the city. The area from the north is limited to the highlands of northern Tehran, from the east to the highway named Ayatollah Ashrafi Esfahani - Mohammad Ali Jenah, from the south to the special road of Karaj and from the west to Can’s waterway. The slope criterion was created using the Digital Elevation Model (DEM) of District 5 and the distance to water wells using Euclidean distance by ArcGIS. Euclidean distance is the direct distance between two points, which in fact is the size of the shortest line between the two points. After reviewing the internal and external resources, we determined the Markgraf and Kay model based on the area of the vacant lands with agricultural potential, so that it could be used as a basis for classifying the 5th district and each vacant land with a designated specific use in urban agriculture. Using the minimum and maximum temperature data, we managed to produce climate condition maps of Tehran province (1996-2014) by ArcGIS.
Results and discussion
Using land use adaptation matrix, it has been determined that some users (agricultural land and garden, leisure activities: parks) are incompatible with utilities such as industrial facilities and installations. Thus, if we consider the vacant land as two productive and leisurely alternatives, they will be in a state of incompatibility with the use of installations and industrial facilities. Therefore, in the ArcGIS, the separation of vacant lands in the vicinity of two industrial facilities and installations was undertaken. Using land use classified information based on the type of dominant function and components; we determined the height of buildings in the 5th municipality of Tehran. Then, with the aid of the computational method we obtained level of building shading in meters. The spatial analysis of the studied criteria suggests that vacant lots with the slope of 0 to 21.9 percent and 168.66 hectares in area, show the distance to water wells with a radius of 262 meters for agriculture in the 5th district of Tehran. Vacant lands were located beside industrial facilities and installations. They were identified incompatible with a total area of 4,363 hectares. In general, the northern parts of Tehran's five districts have low temperatures and southern parts of this region have high temperatures. In the east and west directions of the buildings, due to the high level of shading, it is necessary to cultivate shade-loving plant species in the direction of the south buildings. Due to the low shading level, it is suitable for the sun-loving plant species. The results showed that in the east and west directions of buildings, due to the level of shading, the shade-loving plant species such as lettuce, chicory, mint, spinach and leaf cabbage can be planted for spring and autumn, and in the south buildings due to lower shading levels, it is suitable for the spring and summer harvesting of sun-loving species like tomatoes, corn, cucumber, eggplant, pepper, and beans.
By integrating slope layer, distance to the water wells, the Markgraf and Kay, vacant lands, and land degradation, it has been determined that vacant lands with the potential for farming in in the center of 5th District have a higher density and less area. The domestic studies on urban agriculture have been descriptive and limited to statistical methods and spatial analysis. What comes from domestic studies is less attention to environmental conditions and legal issues of land for farming in the cities, which has been dealt with extensively in previous studies. This study suggested a method for finding the potential areas for cultivating different crops in urban areas. It is hoped that more precise measurements of meteorological variables in future studies improve these works more accurate.