Evaluation of Sustainability of Development in Zone 22 of Tehran by Ecological Footprint Method

Humankind’s demands on the biosphere were in a balance with the Earth natural resources, until the middle of 20th century. Ever since the natural resources increasingly exceeded the supply, and caused environmental destruction and ecological unsustainability (Szigetia et al, 2017). These environmental issues raised the concerns and made the sustainable development concept (He et al, 2016). Sustainable development states a long term development strategy, which considers the future generation needs for development. This kind of development should be the foundation of every region development, thus the protection of environment will be insured. Unsustainable development in a region will reduce biocapacity, jeopardize the environment, and it will cause a number of irrecoverable damages (Sardarabadi et al., 2014). Sustainable development could be assessed through various methods. The presented approach, evaluate the sustainable development of zone 22 of Tehran by calculation of Ecological Footprint. The Ecological Footprint is an accounting tool used to measure mankind’s demand for natural services and biocapacity is the natural ability of an ecosystem to regenerate those services (Wackerngel and Rees., 1996). Since 1961 the balance between biocapacity and Ecological Footprint of Earth has been lost (Ecological Footprint Atlas, 2016). Moreover, with the climate change caused by massive carbon emission (CO2 concentration changed from 270ppm to 400ppm since the industrial revolution), biocapacity is reducing more than before. Global consumption trends reduced the Earth biocapacity to 1.8 Global Hectares and raised the average Ecological Footprint to 2.7 Global Hectares. This peculiar situation leads the world to unbearable ecological condition (Ecological Footprint Atlas, 2016).
Methods and material: Study of sustainable development in Tehran zone 22 is the main aim in this research. The assessment is based on the calculation of Ecological Footprint and biocapacity metrics. Ecological Footprint is the overall usage of natural resources and the generate waste. EF is equivalent to consumption of water, land and all the use of other environmental services, in addition to released carbon and generated waste caused by this consumption. According to the assumptions and as the initial definition, the Ecological Footprint is obtained by dividing the annual demand of one product into its annual efficiency. Also, the Ecological Footprint unit is the Global Hectare. To obtain the world hectare, which depends on the efficiency coefficient (the average national efficiency of each hectare of land to the average global efficiency of that type of land) and the equilibrium coefficient (representing the relative productivity between water and land types), the amount of consumption of each person, Per ton per year, is divided into the final limit of the earth or the water zone, then the amount that is consumed or contaminated is the desire amount, which is called the world hectare. The biocapacity means the ability of the fertile land, which includes natural biotic areas that are used to produce consumable resources, and also to receive waste and residues from their consumption. To calculate the biocapacity, the efficiency coefficient and the equilibrium coefficient for each type of region of the earth is multiplied by its area. It should be noted that each of the zones of forest, pasture, farmland, built and sea, has it specific efficiency coefficient and equilibrium coefficients. Scientifically, when the two parameters are equal, the development of a region is stable. To calculate the biocapacity, two Google Earth and Arc GIS software were used and the area of available regions was calculated for each land use.

The difference between the amount of Ecological Footprint and biocapacity determines the level of instability in the area; so, if this difference is high, the development of the region is an acute and very concerning. According to the results obtained in this study, carbon footprint with a total amount of 2.57 units per world hectare, compared to land, forest, pasture products, agricultural products and seafood, which were 0.09, 0.11, 0.41, 0.83, and 0.1 world hectares respectively, are significant. Also, according to the results obtained in region 22 of Tehran, the distribution of carbon in the commodity sector is the highest in terms of the area and type of use per unit of world hectare. It is approximately 0.8 and this is a threatening. In transportation sector, the services and construction, which include the next higher values, are 0.62, 0.6 and 0.43 world hectares respectively, all of which cant be ignored. Finally, the carbon footprint in the food sector is considered to be 0.12 world hectare, and has less rank and actually less vulnerable than the other factors mentioned, but it needs to be considered fairly. In the following, comparing the Ecological Footprints of This region with other major parts of the world, the location of Tehran's 22nd region, after Kyoto with 2.38, Campo Grande with 3.14 and Hong Kong with a value of 4 world hectares, which is equal to 4.11 world hectares, Sao Paulo, New York, San Francisco, Ontario and Calgary have values of 4.38, 6.1, 7.1, 8.4 and 9.86 world hectares, respectively, have a higher Ecological Footprint than Tehran's 22nd area, and the Ecological Footprint of all cases are higher than the acceptable global limit for the Ecological Footprint of the world, and this is a threat, and it is required to take action to reduce and perhaps eliminate the damages. Biocapacity of Tehran's 22nd district, which includes the total capacity of all areas, was estimated at 5549 world hectares. By dividing this amount into the population of the region in 2015 (equal to one million and one hundred thousand), biocapacity was estimated at 0.005 world hectares per capita. By comparing it with Iran, Asia and the world, it was determined that Tehran's 22nd region has a much lower capacity than the mentioned ones. To estimate the Ecological Footprint of the 22nd district of Tehran, population density and information related to lifestyle were used and the rate of this parameter was 4.1 world hectare per capita. Comparing the Ecological Footprint of the 22nd district of Tehran with the average of this index in Iran (2.67), Asia (1.8) and also in the world (2.7), it was determined that the 22nd district of Tehran has a more Ecological Footprint amount than all these. There is a need to reduce the Ecological Footprint by changing the pattern of life and reducing population in the region.

Cause of immoderate difference between Ecological Footprint and biocapacity in this region it’s accurate to assess the development, in an unsustainable situation. The main reason of this difference is lack of infrastructures in zone 22. With two times more population than master plan, biocapacity is less than half of the predicted amount. As a region with high mid-income level, in case of mismanagement Ecological Footprint of Tehran zone 22 could reach to 6.2 Global Hectares. Zone 22 needs an immediate management on population density with decrease in urban construction, especially near the Chitgar artificial lake. It worth mentioning that Ecological Footprint decrease is an achievable goal. Germany was successful to change the people Ecological Footprint from 6.8 Global Hectares in 1990 to 5.2 Global Hectares in 2012.