تحلیل و ارزیابی شاخص‌های ریخت‌شناسی شهری محلات قدیمی از منظر توسعه پایدار (نمونه مطالعاتی: محلات کبابیان و کلپا شهر همدان)

Introduction: Today, the morphology of some Iranian cities has been rapidly formed in accordance with the rapid growth of urbanization, and the issue of sustainable urban morphology has been ignored. On the other hand, the growth of cities in the current century and the issue of creating new cities in the past half century have been raised and implemented as a necessity for the overflow of urban population in order to decentralize population and employment in the world, including in Iran. In fact, urban morphology has been one of the most important physical approaches to cities, the basis of its studies is the study of the physical changes of the city's architecture over time, which leads to the gradual formation and creation of layers of urban structure development. The present study analyzed and evaluated the urban morphological indicators of the old neighborhoods of Hamedan from the perspective of sustainable development (Kelpa and Kababian neighborhoods).
Materials and Methods: This research is an applied research and is descriptive-analytical in terms of method. Urban morphological indicators in line with sustainable development were extracted from the research background in the form of a library. Since the model used is the random forest algorithm, a series of test and training points were also developed in this regard. In this research, different layers and images from the organization and sites were first obtained and entered into ArcMap software. In order to analyze the data, 15 different indicators and layers were used, including access to communication routes, access to transportation, access to educational centers, access to commercial centers, access to health centers, building age, building materials used, vegetation index, land surface temperature, fractal index, The texture condition, width of passages, population density, building density, and sky visibility coefficient, which are stable morphological indicators, were analyzed using the random forest algorithm.
Results and Discussion: Based on the findings of the two neighborhoods of Kalpa and Kebabian, it was determined that the amount of vegetation cover in both neighborhoods is less than the standard per capita and this issue should be addressed. Also, the building density and population density in both neighborhoods are high. Access to transportation centers is somewhat low and most of the transportation is concentrated in the northern part of Hamedan city. The condition of the materials used and the age of the buildings in these two neighborhoods are very inappropriate and in an unstable state. In general, it can be said that the new and planned structures, which were generally built after the Islamic Revolution and where the prices of land and housing are high, are in a stable or semi-stable state. The characteristics of this texture include regular and coarse-grained separation, hierarchical network of passages, attention to green space per capita with new buildings and quality materials. Also, the old and unplanned texture, which is characterized by small houses, irregular separation, lack of attention to access hierarchy and no green space, is in an unstable state. In addition, land and housing prices in these neighborhoods are lower than in other areas.
Conclusion: The results of this study showed that despite the old texture of both neighborhoods, the Kalpa neighborhood had a relatively newer texture than the Kebabian neighborhood in most of the research indicators, which indicates that it has undergone changes in recent years. The reasons for this can be attributed to economic, geographical, and social elements. Therefore, it can be said that since before the Iranian Revolution, the rapid change in the economic and social structures of the city has affected the urban form, and today it is developing at a faster pace. This has led to the asymmetry of urban neighborhoods.