Ecological footprint, a road to the sustainability of cities (case study: Tabriz city)

 Introduction:
The concept of sustainable development is expanding internationally, and therefore scientists have provided several quantitative and qualitative models for measuring the sustainable development of communities and cities. One of these tools, which attracts more attention in the scientific, political and educational levels, is the assessment of ecological footprint. According to this method, the development is considered unsustainable, when the ecological footprint is higher than the biomass of the region. The ecological footprint approach has been used to measure the sustainability of major cities around the world, such as London, Liverpool, and Paris. The aim of this research is to measure the stability of Tabriz city using the ecological footprint method.
Material and methods:
In this research, descriptive-analytical and quantitative methods were used. The data of this research are mainly quantitative. The population under study included all households living in Tabriz. All data were obtained either from documents (e.g., library and electronic databases) or during field works. In this study, cluster random sampling method was used. The city of Tabriz was categorized into 10 regions based on municipalities and from each region several blocks were selected by sortition. A syncretistic ecological footprint method (a combination of inductive and deductive methods) was used to calculate the ecological footprint in the urban areas. The data necessary for initial analyses were obtained using the country’s statistical data. These include energy consumption, forestry, and its utility.
Results and discussion:
To determine the ecological footprint of Tabriz, data from food, carbon dioxide emissions from transportation, heating from natural gas, water, electricity, and the amount of waste was used. The results show that the city of Tabriz requires an average of 10.86 trillion hectares of land per year for landfill. The required area to absorb the carbon derived from the consumption of the natural gas for each citizen and the whole population is 135 square meters and 20,795 hectares, respectively. The electric power footprint of each citizen of Tabriz is 0.17 hectares. Finally, the water consumption footprint of Tabriz city is 0.020 hectares.
Conclusion:
The results of this study indicate that the ecological footprints of Tabriz city in categories such as food products, transportation, heating from natural gases, water, electricity, and the land needed for waste disposal were 3.30 hectares. Our results suggest that the city of Tabriz relies on a region beyond East Azarbaijan Province to meet its biological needs and sustainability. The amount of consumables in Tabriz shows that food with 2.73 hectares has the highest share compared to other factors. The lowest amount of area needed for waste disposal was 0.77 square meters per person. Since Iran's biocapacity is 0.8 hectares, the ecological footprint of 3.30 hectares in Tabriz city indicates that the city allocated 125.4 times more than its share of the country's biological capacity to itself.