Estimation of urban sprawl and its impacts on land use/land cover changes (case study: Zanjan City during 1986-2016)

Nowadays, the urban sprawl phenomenon has become one of the most important concerns of planners and policymakers. The lack of attention to this phenomenon has led to irreparable consequences such as threatening natural resources, and social, economic, physical, and environmental constraints and disadvantages. In order to better understand such a model, it is necessary to evaluate and identify the socioeconomic factors affecting it.

  the methodology in this research was a combination of descriptive and explanatory research, the type of research was applied, and its approach was considered quantitative and qualitative. Data collection was done using library and field survey methods. Also, remote sensing and Landsat satellite images of the studied area during the mentioned period was used. In addition, to analyze Zanjan’s urban sprawl, the method of classified classification, land use classification and cross-feasibility model, the extent of changes in different land uses, and the Holdern model were used. In order to predict the trend of changes and to investigate possible changes in land uses for the 2026 horizon, the Markov chains model was used.  

In the studied area, the results of the research indicated that over the past three decades, with uneven development in Zanjan City, the urban area has almost tripled. Theoretical analysis of Zanjan’s urban sprawl according to Heldern model indicated significant urban sprawl domination in the physical development of Zanjan, which always had more effect than the population growth. During the studied years, Zanjan’s urban area had a multiplier increase that in contrast to this expansion, had a significant decrease in orchards and agriculture. In this situation, what made a big difference were the changes in orchard and agricultural land uses. Translation errorThere were many factors involved in this matter, most notably the growth of urban population and urban sprawl.    

Based on the forecast for 2026, the probability of land use changes to the city over the next 10 years is significant, during which Translation errorthe amount of built-up areas in Zanjan will reach 6311.88 hectares. It should be noted that orchards and Translation erroraaaagricultural lands have only a 23.56% possibility of conversion to urban areas. Therefore, necessary actions are required to prevent over-urbanization. In developed countries, considering the importance of sustainable development, environmental protection and the efficient use of various sources, smart growth, and urban development are highly important. Moreover, preventing the excessive growth of the city's boundaries, the high-ranking agenda, and the use of the compact city pattern, as well as the direction of the expansion of the city towards regolith and abandoned lands with the aim of preventing constructions in agricultural land can be considered.