Sedigheh Lotfi; Toheed Alizadeh
Abstract
Land is a vital natural resource for human survival and the basis of all ecosystem services. However, land degradation in the form of land use and land cover changes has been a severe problem in the world. Rural-to-urban migration in developing countries, as well as the conversion of many nearby villages ...
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Land is a vital natural resource for human survival and the basis of all ecosystem services. However, land degradation in the form of land use and land cover changes has been a severe problem in the world. Rural-to-urban migration in developing countries, as well as the conversion of many nearby villages into urban areas, has largely caused a rapid increase in the size of urban settlements. The evidence shows that the North of Iran is experiencing rapid changes in land use, which has endangered the stability of the region during the last three decades. This article aimed to identify and compare the changes in the growth of the city and the expansion of the city for the study case of Amol located in Mazandaran province in three decades from 1986 to 2016. Therefore, in order to produce land cover changes images Using Landsat time-series image data (TM, ETM+ and OLI/TIRS sensors), the Linear spectral unmixing model has used with the extraction of endmembers and two classes of urban and non-urban lands were identified for each time section. Spectral unmixing method as a new method in the analysis of land cover changes has been less discussed in research related to urban issues. Accuracy assessment of land cover classification, using the confusion error matrix with the calculation of overall accuracy above 90% and kappa coefficient above 80% for the obtained images, shows high and very good accuracy. The findings showed that the doubling of the city's population in these four decades has not only been accompanied by a horizontal expansion of 60% in the surrounding green and open lands, but has also resulted in an increase in building density and the number of floors. In these four decades, the expansion of Amol city has generally been from the center to the periphery, and the least changes have occurred in the central parts of the city and the most changes have occurred in the northern and eastern parts of the city.
Mohammad Soleymani lamyani; Amer Nikpour; Sedigheh Lotfi; hammed Abbasi
Abstract
The form of the city is very important because it forms the basis of urban movements within itself. One of the key components of treating the quality of the urban form is access to urban activities and services. The expansion of the horizontal growth of the metropolis of Tehran in the last few decades ...
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The form of the city is very important because it forms the basis of urban movements within itself. One of the key components of treating the quality of the urban form is access to urban activities and services. The expansion of the horizontal growth of the metropolis of Tehran in the last few decades has caused the fabric and structure of this city to move towards instability, which results in unequal and unbalanced access to different parts of the city. Therefore, the structuring of the city in such a way as to meet the needs of the citizens in the shortest distance from the residential area and easily, is very important in urban planning. The present research was conducted with the aim of investigating the condition of the form and accessibility of the neighborhoods of Tehran. The necessary data and information were extracted from the statistical blocks of the Statistics Center, the land use map of the city, and the Open Street Map website, and GIS and Excel software were used to analyze the data. 3 main indicators of density, connection and mixing were used to evaluate the urban form, and Hansen's gravity model was used to measure accessibility. The results of the research showed that the neighborhoods in the central part of Tehran have a more stable form compared to other neighborhoods, and the western neighborhoods of Tehran have an unstable form. The access factor in Tehran also showed that the central and northern parts of the city are in a better condition than other parts of the city in terms of access. The results obtained from the correlation test also showed that there is a direct and significant relationship between urban form and accessibility; But the degree of correlation between them is not strong. Meanwhile, among the urban form indices, the building density index has the highest correlation with urban accessibility.
Keywords: urban form, accessibility, density, urban neighborhoods, Tehran.
