تحلیل و ارزیابی شاخص های ریخت شناسی شهری محلات قدیمی از منظر توسعه پایدار (نمونه مطالعاتی: محلات کبابیان و کلپا شهر همدان)

Introduction

Today, the growth of urbanization is progressing so much that according to studies, although the rate of urbanization was about 48.3% in 2000 and reached 56% in 2021, it is expected to exceed 68% in 2050. Therefore, in recent decades, one of the basic pillars of sustainable development is achieving sustainable urban development; But since cities have a complex system, their conditions are not always simple and changeable; Therefore, it is necessary to carefully evaluate them from the point of view of sustainability and to investigate and identify the factors affecting sustainability. Based on this, city morphology is defined as the pattern of spatial distribution of human activities in the city, which has a significant impact on the sustainability of the built environment. Morphology is the study of the appearance of the city, the gradual formation of its texture, and the interrelationships of the components of this texture that affect urban spaces such as streets, squares, buildings, and other public spaces. Paying attention to morphological aspects is one of the debatable topics, especially in historical urban contexts, which is used for sustainable development goals and results. Therefore, the main goal of this research is to analyze and evaluate the urban morphological indicators of old neighborhoods from the perspective of sustainable development at the level of Kababian and Kolpa neighborhoods in Hamedan.

Research Methodology

The current research is of the type of applied research and according to the descriptive-analytical method. The indicators of urban morphology in line with sustainable development were extracted as a library from the background of the research. Since the model used is a random forest algorithm, a series of test and training points were also developed in this regard. In this research, first, different layers and images from organizations and sites were taken and entered into ArcMap software. In this software, the vegetation index was first calculated to obtain the amount of vegetation in the area and the temperature of the earth's surface. These two indicators are extracted from Landsat 9 satellite images. Vegetation index was obtained from bands 5 and 4 and surface temperature index was obtained from bands 10 and 11. Also, other indicators such as population density, building density, etc. were calculated in this software.

Results

In this section, we will examine and evaluate the two neighborhoods of Kababian and Kolpa in terms of the stable level of morphology. In this research, out of 15 indicators that include (the level of access to health and treatment centers, education, transportation, commercial, population density, texture condition, building density, sky visibility factor, ground surface temperature, vegetation condition, road width, building life, fractal index, building materials, access to main and secondary roads) have been used. Using random forest algorithm, the results showed:

The amount of vegetation in two localities is less than per capita, and this should be taken into account. Building density and population density are high in both neighborhoods. Access to transportation centers is somewhat limited, most transportation is concentrated in the northern part of Hamadan city. Also, the condition of the materials used and the life of the building in these two neighborhoods are very inappropriate and in an unstable state. In general, it can be said that the new and planned contexts, which were generally built after the Islamic revolution and the prices of land and housing in them are high, are in a stable and semi-stable state. Among the characteristics of this texture, we can mention the orderly and coarse-grained separation, the network of hierarchical roads, attention to per capita green space with newly constructed buildings and quality materials. Also, the old and unplanned structure, which is characterized by small houses, irregular segregation, lack of attention to the hierarchy of access and no green space, are in an unstable situation. In addition, the price of land and housing in these areas is lower than other areas.

Conclusion

Overall, the results of this research showed that despite the old texture of both Kababian and Kolpa neighborhoods, Kelpa neighborhood had a relatively newer texture than Kebabian neighborhood in most of the research indicators, which shows that it has undergone changes in recent years.