Investigating the challenges of urban development with emphasis on physical indicators(Case study: Arak city)

Unplanned physical development causes problems that cause urban societies in socio-economic and environmental crises, which are very difficult and complex to solve after the development of urban areas. Most cities in Iran face many physical challenges, of which the city of Arak is no exception and has many physical limitations. The southern part of Arak city is surrounded by steep heights and now part of the slopes of these heights, which have a considerable slope, is occupied by marginalized people. Not only is this part of the city lacking in development, but part of its population will be displaced if the worn-out structures are rehabilitated and renovated. This study seeks to analyze the challenges of urban development in Arak with emphasis on physical indicators and then the most appropriate and unsuitable areas of the city in terms of physical indicators are identified.

This research is based on applied purpose and its method is descriptive-analytical. Documentary and library methods have been used to collect existing theories and experiences. Examining the current situation of Arak city in terms of access to required information and surveying 40 urban experts using a questionnaire, 5 main criteria including incompatible uses, natural factors, compatible uses, population and density, characteristics of residential units were selected. AHP model was used for weighting. GIS and Index Overlay method have been used for the final combination of layers. After the criteria of physical indicators (incompatible uses, natural factors, compatible uses, population and density, characteristics of residential units) were determined and the information related to each of them was prepared, the weight of each of them was compared using AHP model. Pairs were performed and maps and layers of each were prepared in GIS. Once the criteria were determined and the final score of the options was calculated, the judgments were logically adjusted. Among the research criteria, the characteristics of residential units with a weight coefficient of 0.3828 have the most impact on the analysis of physical indicators and the lowest coefficient of importance is related to population density with a weight of 0.082. Then, the map of each criterion was prepared in Raster format, including compatible and incompatible land use maps, population and density, natural factors, characteristics of residential units and population density. Each of the desired criteria was classified according to its sub-criteria using the Reclassify command and the desired weight, and with the Raster calculator command, a map of each of the first level criteria was prepared for the final composition and integration. That is, all 5 criteria of the first level, based on their respective weights, were combined using the INDEX OVERLAY model and the final map of the analysis of physical indicators in Arak was determined.

Findings show that physical indicators in the design and urban planning of Arak city are not related to social readiness and safety of citizens so that: 1) the most unsuitable area based on the index of natural factors in area 3 and the most appropriate area 1 2) The most unsuitable area is based on the index of characteristics of residential units in areas 3 and 5 and the most suitable is area 4, 3) The most unsuitable area is based on the incompatible land use index of area 1 and the most suitable area is parts of area 3, 4) The most unsuitable area based on compatible land use index is parts of region 3 and the most suitable are parts of region 1, 4) The most unsuitable area is based on population density index of region 1 and the most suitable is region 5. Among the research criteria, the characteristics of residential units with a weight coefficient of 0.3828 have the most impact on the analysis of physical indicators and the lowest coefficient of importance is related to population density with a weight of 0.082. The results show that in the central areas of Arak city, especially in the south of region 5, region 3, and the northwestern part of region two, as well as in the central part of region one (industrial centers), are the most unsuitable areas in terms of physical development and more From other areas, there is a need to plan and take executive measures to reduce physical challenges.

Arak urban development can be done in two ways: connected development and internal development. A noteworthy point in identifying the possibilities of growth and development of Arak metropolis is the existence of barren lands and the ability to reclaim land within the city, which is due to the physical development of centralist forces (under the influence of spatial concentration hypothesis that causes savings due to scale ), Include a significant area of the city. This, along with identifying other components affecting the growth and development of the city, including environmental and spatial potentials, provides opportunities for the physical development of the city. To reduce physical challenges in Arak, it is suggested that planning priorities be considered as follows; 1- Neighborhood criteria with incompatible use in areas 3 are in the planning priority; 2- Criteria of population density in the planning priority of regions are 4 and 5; 3- The criterion of compatible uses in the planning priority is region 3; 4- Criteria of residential features are in the priority of planning areas 3 and 5; 5- The criterion of natural factors should be a priority in the planning of region 3, and finally it is suggested to prepare a comprehensive and complete plan in this field and to conduct more in-depth studies on the physical condition of the city separately for each of the urban areas of Arak. The present study has been able to study some of the challenges of urban development in one of the industrial cities of Iran. So far, less study has been done on the physical indicators of Arak and its impact on the development of the city.