The Evaluation of Urban Parks and Green Spaces Per Capita and their Accessibility with Ecological Approach

The important roles played by green space are the social, economic, cultural and environmental aspects of sustainable development. Thus, the quality and quantity of green space should be appropriate to the physical size of the city and the needs of society and also it should be developed according to the ecological conditions of the city and its future development trend. Therefore, development of urban green spaces results in urban ecological development and causes the promotion of urban life level and sustainable development of cities.
For having all residents access green spaces and having reasonable green space per capita and also distribution of these breathing lungs in all neighborhoods of cities, creating active green spaces with continuous environmental performance is important. The process of dealing with urban green spaces from the past indicates that if this trend continues, destructions and green spaces land use changes; the result can be a threat to sustainable development and ecological balance in Tabriz city and even in the region.
This research by analyzing the existing per capita and comparing it with the standards, estimates the required green space area for all locals of Tabriz. Also by network analysis of Tabriz passages, it tries to analyze the accessibility of local parks in terms of access walking time and estimate areas that are outside the radius of citizen's access for consideration of city managers and authorities for future plans.
The definition of urban green spaces which is agreed on by ecologists, economists, social scientists and planners is public and private open spaces in urban areas, primarily covered by vegetation, which are directly (recreational function) or indirectly (has an impact on the urban environment) available for the users(Shah & Atiqul, 2011,). According to the Ministry of Housing and Urban Development Studies, conventional and acceptable per capita for urban green spaces in cities is between 7 to 12 square meters per person. That in comparison with the index set by the United Nations environment (20 to 25 square meters per person), is low. However, in cities across the country, this figure, according to the different geographical and climatic characteristics is different, which the approved plans of each city determines it ( Akbarpour Saraskanroud, Garakhlou ,Norouzi., 2009).
This research is applied research and has descriptive¬-¬analytical methods. In this study, according to the current master plan of Tabriz metropolitan, which is currently being prepared, local parks per capita in deferent districts were assessed separately. Existing per capita was compared with the standard per capita for local parks and green spaces till deficiencies were extracted. Also, their impact on ecological and environmental conditions of the locals was investigated. In this study, per capita criteria, is intended 9 square meters based on the master plan of Tabriz. Also to estimate the level of citizen's access to local parks, with using network analysis in GIS software, Tabriz metropolitan resident's access to local parks and green spaces have been measured. Normal walking speed is about 0.75 to 1.2 meters per second, and in this study walking speed is considered about 4 km per hour. With the designing of access networks in Tabriz, all parks’ service areas were determined by defining the maximum interval (15 minutes). According to the standards the radius of neighborhood parks function is about 600 to 800 and sometimes up to 1000 meters. In this study, three accessible time areas for citizens 5, 10 and 15 minutes were determined by using network analysis in GIS software. For doing this analysis, the data related to access network in Tabriz city and the position of existing parks, the GIS maps from Tabriz Municipality, Department of Planning and Architecture were used.
According to the studies, Tabriz metropolitan, following the increasing speed of the city's physical development, especially in recent decades, has been extremely damaged about important ecological elements, especially in green spaces and has increasingly lost these valuable spaces for the economic benefit in the form of urban projects and physical development of the city. The importance of local parks because of accessibility of all citizens for recreation and ecological benefits is more than any other green space in larger scales. The studying of area and local park’s per capita in the entire city, shows the lack of parks in the city, especially in dense urban texture and including districts of 8, 4 and 3 Tabriz municipality.Also by using network analysis, citizen's access to local parks in all districts were measured separately and according to this study 5, 9 and 7 districts have the least access to parks.
Considering research findings, per capita deficit and access problems to local parks and green spaces cause ecological and environmental problems in the city areas, especially in dense locals of Tabriz. Thus, for having ecological benefits of urban green spaces, especially in the locals, planning for urban parks and green spaces in proportion to the density and texture of urban localities to increase the green space per capita and consequently good access to the city's vital elements, is one of the requirements of urban planning for urban development.