Investigating and studying the physical development bottlenecks of Shiraz from the perspective of geomorphology

Introduction:

The present research is dedicated to investigating and studying the physical development bottlenecks of Shiraz city from the perspective of geomorphology. In a general definition, geomorphology is: the science of the unevenness of the earth's surface, and its task is to recognize and categorize (classify) these shapes for planning in the environment. The shape of the earth's features or geomorphological phenomena plays an effective role in the formation of human settlements, especially cities, and sometimes they encourage and cause the physical development of cities, and sometimes they also hinder development. The major issues and problems that In the way of the physical development of cities, including the city of Shiraz, there are obstacles that nature has created, and in some cases, the lack of correct decision-making by urban planners and managers in the location of industrial projects and settlements are considered important factors. Considering that the most important mission of science is to bring people to prosperity and improve the quality of human life in the geographical space, and to preserve their lives and their current position against instabilities is the biggest concern of humans, which is the source of nature and also the lack of attention of humans. The inhabitant of planet earth is to it. Therefore, the science of geomorphology seeks to identify these factors and provide scientific solutions to deal with these problems.

In this research, an attempt has been made to investigate the natural and geomorphological obstacles to the physical development of Shiraz, and in accordance with the intended goals, which is to analyze the effects of natural disasters on the construction and urban infrastructures of Shiraz, as well as to identify and determine bottlenecks and sensitive and vulnerable lands in order to prevent or pay more attention to construction on them, it is an important step.

Chapter One:

Overview of the research

1-1- Statement of the problem:

The development of world cities has been very fast in the 20th century and it seems that this trend will continue in the future. 60% of the total population lived in cities (Thoruti, 1380: 2).

The trend of urbanization in Iran following the profound economic and social changes of the previous decades has led to the unbridled growth of national and regional cities in recent years and has brought unpleasant consequences in the physical and biological space inside the city without matching the capacities and natural facilities of the region. The growth of the population by occupying the urban space has created an imbalance in the construction and fabric of the city and has caused irreparable damage to the urban environment. In most of the cities of Iran, harmony and adaptation between the physical growth of the city and the natural environment is not seen, and in many of these places, the natural environment has created limitations in the directions of growth and caused the concentration of the population in another direction. The city of Shiraz, as one of the largest residential bases in the south and southwest of Iran, which, according to the census of 2015, has a population of (1,204,872), has expanded during its time and according to natural conditions. found, to the extent that urban planners are looking for the location of the overflow of the current and future population. (For example: the creation of the new towns of Sadra and Golestan in the west and northwest of Shiraz).

It seems that one of the important things that should be the focus of attention as a basis for urban planning or residential and even industrial complexes in any region of any size is the study and recognition of the natural complications and geomorphology of that region.

Especially in Iran, it can be seen that the expansion of some of these population bases has been subject to the natural structure of that region. The city of Shiraz is not separate from these natural considerations, and a quick look at its topographical situation and its structural and morphological evolution shows complications that in the current situation are presented as geomorphological obstacles and bottlenecks in the development and expansion of this city. By referring to the 1:50,000 and 1:250,000 topographic maps of Shiraz, it can be seen that the city of Shiraz is a large and large part of the Shiraz plain by the lake. Maharlust and the shape of this plain is almost linear, which narrows on the west side of the plain and vice versa, opens and widens on the east and south sides. This plain is one of the plains within the Zagros mountain range and in terms of natural structure, it is in the form of a navadisi, which is surrounded by two relatively high mountain ranges in the north and south.It has the highest elevation in the west direction and the lowest elevation in the east direction, and for this reason, in the south and southeast direction of the city and the Shiraz plain, we have a decrease in the slope and correspondingly high groundwater level, and it has become one of the inhibiting factors and bottlenecks for the development of residential and urban areas.

Tectonically, the Shiraz plain is located in the regularly folded region of the Zagros and in the severe tectonic region, and there are many faults and fractures in the watershed. Shiraz plain can be seen. Based on the sensitivity of the formations and lithological units of the region and the behavior of the geological formations against the fracture of some of the formations that make up the region, such as the Asmari, Pabdeh, Fahlian, Jahrom and Aghajari formations, which make up a large part of the studied area, have maximum faulting and faulting, and this indicates that the frequency of earthquakes is high in the Shiraz region, and it can be called as an important geological geomorphological factor in the matter of urban development. Another point about the study area is the area of ??the dry river (Nahr Azam), which, like the urban development of Shiraz, which has a west-east linear trend, this river also flows from the west to the east. It is causing depression, just as in the past, the flood caused by the dry river of Shiraz has also affected the city (floods of 1365 and 1380).

     In the studied area, there are factors such as the presence of Qasr al-Dasht gardens in the northwest part of Shiraz, fields and agricultural lands in the south and southeast of Shiraz, as well as the location of Shiraz airport and small industrial towns in the south are also factors that are bottlenecks and obstacles to physical development. The city of Shiraz is considered to be that the possibility of urban development in these areas is faced with physical growth limitations. Also, the southern and northern unevenness of Shiraz city with inappropriate slopes for the development of the city can be added to the above. Research questions: 1) What are the natural factors and geomorphological phenomena that have led to unfavorable physical development in the city of Shiraz? 2) What impact have these factors and phenomena had on the physical development process of the city of Shiraz?

1) The shape of the land and the lack of human attention to it have had the most adverse effects on the physical development of Shiraz. 2) According to the processes and geomorphological elements and the natural strength of the region, the physical development of Shiraz in the north-northeast and south-southwest direction is not possible, and the physical development of the city has taken an east-west trend. 4-1- Research objectives:

  In the context of the physical expansion of the city, geomorphological and natural factors are taken into consideration in terms of the human influence in changing the shape. On the other hand, geomorphology, as a knowledge and technique in environmental construction, can show how natural facilities and limitations appear in the field of urban planning. In the case of Shiraz city, it is possible to prevent its expansion in unsuitable lands and the occurrence of serious natural hazards by using the achievements of geomorphology research along with other studies related to planning. On the other hand, knowing the positive capacities and capabilities that the natural environment provides, he planned to use the environment as best as possible for the comfort of the citizens. including the creation of parks, recreation areas, etc. In general, the main goals of the above research are summarized in the following: 1) Analysis of the effects of natural disasters on the constructions and urban infrastructures of Shiraz. 2) Identifying and determining bottlenecks and sensitive and vulnerable lands in order to prevent or pay more attention to construction on them. 5-1- Spatial area Research: Shiraz metropolis, as the capital of Fars province, is located on a long plain 120 km long and 15 km wide, in the eastern longitude of 29.52 to 36.52 in the northern latitude and 33.29 to 29.41, 900 km south of Tehran.