The role of geomorphological factors on the physical development of Arak city in order to develop a conceptual data model

Dissertation for M.Sc degree

Natural geography-geomorphology in environmental planning

Abstract

The city expands in the geographical environment not based on capacity and facilities, but based on urgency and necessity. This issue is very noticeable in today's cities. It is noteworthy that the city must be in harmony with its natural location and it is essential that humans can establish a logical relationship with the ground. Therefore, in the current research, the geomorphological factors affecting the physical development of Arak city have been investigated and a conceptual data model has been designed for the physical development of the city, in such a way that it can be used as a model for other cities. The work unit was defined based on the landforms of the region. A physical development study of Arak city was conducted based on indicators such as height, distance from fault lines, geomorphological map, land use, continuity of Arak city, seismicity, slope, suitable distance to Miqan desert and runoff height. The desired indicators were standardized based on fuzzy membership functions. Then the relationships of the indicators were evaluated based on Pearson's correlation coefficient, one-way analysis of variance (ANNOVA) and clustering in landform units. In order to determine the priority of landforms for the future physical development of the city, TOPSIS model was implemented. In line with the implementation of the model, the weight of the variables was done based on the opinion of experts by the AHP model. The results of the analysis showed that the first priority for the physical development of Arak city is located in the northwest of this city. The substrate of the proposed space was investigated from a natural point of view. Keywords: geomorphology, physical development, conceptual data model, Arak city. Chapter 1. Introduction to the research. 1-1. takes" (Rahmani, 1387: 9). "In these conditions, the physical development of cities usually happens regardless of natural factors. Among the consequences of this type of physical development in cities are: destruction of gardens and agricultural lands in favor of constructions, encroachment on the privacy of rivers and environmental values, development on steep slopes, inappropriate adjacencies in uses. In order to minimize the adverse environmental effects resulting from such a process, in addition to other socio-economic and political factors, it is necessary to pay enough attention to the natural factors and characteristics of the land as the main basis of physical development" (Karam and Mohammadi, 2018: 60).

"The uncontrolled expansion of cities is a global problem and it is predicted that by 2025, more than 65% of the world's population will live in cities, at the same time, the rapid increase in dispersion Urban leaves harmful effects in the environment" (Kaya, 2006:19).

"As long as the growth pattern of cities was organic and endogenous and local factors were the determinants of urban growth, the urban land provided enough for the traditional urban uses and organized the city space organically according to the economic, social and security conditions of the city" (Majdi, 2006: 6), but today the urban land for the population has flowed to It is not enough and it requires basic studies in the field of land and urban geomorphology and finding the optimal place for the establishment and physical development of cities. These materials and forms may be inherently suitable for certain activities and make cities face risks in different stages of development. On the other hand, most of the land features are not compatible with their current environment. Most of them were formed under a set of climates with different conditions such as glaciers or old ice sheets. These effects may persist until they are covered with vegetation or subjected to prevailing rainfall or drainage conditions. However, if this stability is disturbed, they may adapt to the new conditions in equilibrium. The development of the city brings about unfortunate changes in these conditions" (Rostaei and Jabari, 2011: 21).

"The study of demographic characteristics in the city of Arak clearly reveals the need for physical development of this city. The city of Arak has faced low population growth before the beginning of industrial developments. During the formation period of the city until 1335, only 89 thousand people lived in this city. As can be seen in the table and graph below, the population of Arak city has increased from 71,925 people in 1345 to 484,212 people in 1390.The beginning of population changes from the mid-1940s coincides with the industrialization and acceptance of new roles, and as a result, the process of population growth and migration to this city continues until the mid-1970s. After this decade, the population growth of the city has mostly been based on natural population growth.

Using the exponential growth model, it has been determined that the population of Arak will reach 526,431 people by the year 1400, which will increase by 79,000 people compared to the population of 1985.

Therefore, the rapid urbanization in the peak periods has significantly affected the physical expansion and the direction and intensity of the city's growth. (Talkhabi, 1391).

1-2 Statement of the problem

The increase in human population in cities has created an increasing need to occupy the land around each city, which is closely related to the natural bed, environment and geomorphological indicators of each region. So that today in most cities of Iran there is no harmony between the physical growth of the city and the natural environment. If the city expansion process is formed without proportion to the capacities and natural facilities, it will create unpleasant consequences in the physical-biological space within the city. Among these consequences are the occurrence of natural hazards, disruption of the environmental balance and disruption of services. Therefore, it is necessary for man to be able to establish a logical relationship with the ground.

The studied area, the city of Arak, is one of the cities that has experienced rapid growth with the establishment of industries in the 1950s and it became a province in 1356. has done A survey and study of geomorphological variables influencing the physical development of Arak city, such as: height, slope, distance from Miqan desert, height of runoff, geomorphology, seismic points, land use, distance from fault lines and distance from the city, can help to create a favorable spatial model for the physical development of the city. If this issue is not taken into consideration in the prepared plans and plans, it will have adverse consequences. Therefore, as much as possible, one should try to prevent the expansion of the city towards the undesirable areas and arrange a suitable place for the development of the city with the desired measures and plans.

The arrangement or spatial structure of data in applications is proposed as a conceptual data model [1], which provides a simple algorithm for complex spatial structures. This helps in practical use of research results. Therefore, designing a conceptual model is one of the necessities of geographical research. Research question:

What is the most important geomorphological factor in the physical development of Arak city?

1-3 Research hypothesis

A suitable distance from Miqan playa is the most important factor in the physical development of Arak city.

1-4 Research objectives:

- Knowing the geomorphological phenomena and processes affecting the physical development of the city and the facilities and limitations these factors have for development

- Development of a conceptual data model in ways that can be used for other cities.

- Determining the appropriate direction and way of physical expansion of the city to respond to current needs and predict

future needs. Research

Physical development in cities has a rich literature, because with the acceleration of urbanization and the extensive need to occupy space, planners have paid attention to this matter. In the world and in Iran, extensive research has been done in the field of physical development, and the most important research carried out inside the country is as follows: In a research with the topic of "Investigation of the natural bottlenecks of the physical development of Sanandaj city", Tharvati et al. Some studies have come to the conclusion that factors such as the heights of Abider, the hills inside the city and the Qeshlaq River have created bottlenecks for the development of the city. So that only 4.81% of the studied area is considered suitable for the development of the city.