جستجوی مقالات مرتبط با کلیدواژه « spatial expansion » در نشریات گروه « جغرافیا »

Today, in many countries of the world, environmental issues are very important for researchers. In this field, the spatial expansion of urban heat islands is one of the most important environmental issues. Urban heat islands are formed due to the growth of human activities and the dominance of artificial environments on the natural environments. The main purpose of this research was spatial analysis and identification of urban heat islands in Rasht metropolitan. In this regard, four main indicators (Density of land use, Green Infrastructure, Transportation, and Urban density) were selected. Environmental studies, Google Earth software, the master plan of Rasht, and the questionnaire method were used to collect information. The pairwise comparison method was used to investigate the relative weight of the indicators. For data analysis, the Arc Map software used spatial analysis tools such as point density, line density, kernel density, interpolation, Euclidean distance, and Zonal Statistic model. Results showed that the transportation index with a coefficient of 0.44 was more important than other indices in the formation of urban heat islands. The index of the land use density with a comparative weight of 0.341 was the second most important index. The indicators of urban density and natural infrastructure were the third and fourth most important indicators. According to the results obtained from the overlaying of the indicators, the center of urban heat islands was identified in Bagharabad, Chelekhane and Bazar neighborhoods. Spatial analysis showed that the spatial expansion of urban heat island is towards the western neighborhoods of Rasht such as Pirsera and Ziabri. According to the results of the research, in 26% of the Rasht area, the possibility of the formation of urban heat islands was high and very high. Also, in 48 percent of the neighborhoods of Rasht city, in other words, 26 out of 55 neighborhoods of the city the intensity of urban heat islands was high and very high. Therefore, managers and city officials must pay more attention to this issue in planning for the future of Rasht City and adopt policies that reduce the negative effects and consequences of this issue.

The purpose of the present research is to investigate the spatial expansion and develop scenarios related to the future development of the city of Mahabad, considering the role of commercial activities in the physical field. This research is considered to be applied from the point of view of purpose and descriptive-analytical in terms of nature and method. The method of data collection is document-survey and Micmac and Scenario Vizard software were used in data analysis. The results obtained from the entropy calculation show that the physical growth of the city was scattered and non-dense. Also, the result of Heldren's model shows that 48% of city growth is due to population and 52% of city growth is related to horizontal growth and dispersion. In the research process, the most important primary and driving factors related to the future spatial expansion of Mahabad city were identified with an emphasis on the commercial activities of the city, and then according to the importance of drivers and their uncertainty in three cases, 1- (combined use and growth) smart city); 2- Spatial expansion of the city with the same current trend (linear shape) and 3- (Spatial expansion of the city in the form of scattered development in all directions of the city) scenarios were compiled for the city of Mahabad. And in the second step, mixed use and smart urban growth were introduced as the most suitable scenario of Mahabad city, which requires the formulation of strategies, policies and operational plans in line with urban sustainability.

Urban spatial expansion is the result of urbanization's control over the geographical space and it represents the process of land conversion to urban uses. The new trends of spatial expansion, especially in developing countries, are pregnant with numerous social, economic and environmental challenges, and forcasting the spatial expansion challenges is one of the useful methods for finding a sustainable spatial development strategy.The current research is a type of applied-developmental research that was carried out using a qualitative-quantitative method. In the qualitative part of Delphi group decision-making method, the opinion of experts regarding the identification, summarization and comparison of two indicators has been done, and in the quantitative part, the data has been analyzed using Interpretive Structural Modeling (ISM) in Micmac software.The findings of the research show that for internal migrations, population imbalance in the territory, instability of the settlement system, weak legal control, distribution of injustice, foreign migrations, social instability, poverty, destruction of the rural way of life, marginalization, increase in crime rate and Delinquency, poor social control, critical burden of the population, abnormal housing and the decline in the quality of life have the greatest influence and will play a role as the first level of challenging factors in the future of the metropolitan area of Tehran.The results of examining the challenges of the metropolitan area of Tehran show that among the components examined in the metropolitan area of Tehran, the highest level of influence and  is related to the migration component with an influence of 107.5, and this component is the most challenging factor in the future of the metropolitan area of Tehran. will work, and the lowest power of influence and influence is related to the component of annexation, integration and depopulation of villages (with influence power of 67.8).

The third millennium has been called the age of urbanization and the urban population is expected to reach about 6.25 billion by 2050. The United Nations also estimates that the urban population of developing regions will grow at an average annual rate of about 2.02 percent, from 2.67 billion in 2011 to 3.92 billion in 2030. Indeed, the urbanization process is a phenomenon that has become increasingly concentrated in developing countries in recent decades. Although the pace of change varies considerably between countries and regions, in fact all developing countries are becoming increasingly urbanized. The increase in urbanization has caused many problems in urban areas. This has led to the fact that today land use management of urban infrastructure has become the main challenge of many planners and city managers. Accordingly, this study seeks to investigate the scattering around the Tehran-Eyvanekey communication axis, so Pakdasht cities with about 210 thousand people , Sharifabad with about 12,000 people and Eyvanekey with about 12,000 people, make it one of the busiest axes in the metropolitan area of Tehran.

The main purpose of this study is to analyze the process of space expansion and modeling in the axis of Tehran Eyvanekey between 1985 and 2020 using remote sensing data and GIS. To have a comprehensive study of spatial organization of this metropolis, a deductive or inductive approach with a practical nature has been used. The basis of the study is based on using the satellite data and images (Landsat multi-time images) related to different years. Using IDRISI, GIS and GOOGLE EARTH softwares and Fuzzy Artmap LCM, MARKOV and CA models.

In this study, in order to evaluate the pattern of expansion of built areas in the corridor of Tehran to Eyvanekey, TM and ETM + images of Landsat satellite related to the years 1985, 2000, 2011, and 2020 have been used. Based on this, the amount of land use changes in the four periods is as follows: The most expansion of practical surfaces in the axis of Tehran-Eyvanekey with an area of 223250 hectares, dedicated to built areas with an increase of 30,495 hectares over the last 35 years. After identifying the urban expansion pattern of Tehran-Eyvanekey corridor, in the next stage, in order to simulate how land use changes in the axis of Tehran-Eyvanekey for the year 2031, the method of automatic cells and chains has been used. For this purpose, to simulate land use changes in the axis of Tehran Eyvanekey in 2031, land use maps in 1985 and 2020 were used. The results show that according to the trend of urban growth in the region in 2031, the land area will reach more than 50,000 hectares. Also, according to the growth rate of urban areas in this region, it can be seen that during different periods, we see a kind of exponential growth in the study area, so that for the period 1985 to 2000, about 240 hectares per year have been built. This trend of growth has expanded and in the next period, ie 2000 to 2011, this number has reached about 580 hectares, and finally in the last period, ie 2011 to 2020, we have witnessed the expansion of about 2251 hectares per year in the built lands, which can be signs of accelerative urbanization. Therefore, the strategy of increasing physical density and using related methods to guide the development of the city towards greater sustainability, should be on the agenda of planners and those in charge of urban affairs.

Modeling land use changes is an effective way to obtain information about how land use changes over time as well as the factors affect it. So, in order to analyze the process of space expansion and modeling in the axis of Tehran-Eyvanekey, it was modeled over a period of 35 years. The results showed that most of the land use changes during this period are related to the built lands, which due to the location of the built areas along the main arteries has a northwest-southeast pattern that is affected by urban growth in the metropolis of Tehran. As a result, they live in these areas, which are either engaged in the urban industries of these areas or use the satellite cities in this corridor as dormitory cities. Interestingly, as we move away from the main center, the metropolis of Tehran, the rate of urban land expansion decreases, which indicates that due to the low cost of housing in satellite cities, this area is a dormitory for the metropolis of Tehran.

Increasing urbanization in the urbanized world has posed major challenges to the sustainability of metropolitan areas, especially in developing countries in various aspects of sustainable development, and has provided them with the prospect of unsustainable development. Excessive land use and its consequent land use changes and land cover are one of the environmental problems caused by the high concentration of population and activity in metropolitan areas. This study is an applied one in order to monitor the environmental changes caused by spatial expansion of Tehran metropolitan area by descriptive-analytical method and by using remote sensing and GIS techniques land use changes and land cover caused by spatial expansion of Tehran metropolis. Has evaluated and analyzed Tehran. The results indicate that the area of ​​land increased from 34316.1 hectares in 1365 to 68252 67.95 in 1595/6117 hectares related to changes in agricultural lands, orchards and water area. Be it. The results of the Markov Chain Model prediction of the probability of land use changes and land cover up to 1405 also indicate that land use and land cover changes will continue in favor of constructed lands. It is concluded that Tehranchr('39')s metropolitan area has expanded beyond the demographic and ecological thresholds and has led to a significant structural disruption to the environment by moving toward the natural environment. Accordingly, the need to pay attention to new approaches to urban development as well as to provide decentralization scenarios can be a major step towards resolving environmental problems caused by over-spatial expansion.

Tabriz city asthe populous city in the northwest of Iranstarted the rapid spatial- physical expansion in past decades. Tabriz area in1335 to 1385 increased from 1770 to 25000 hectare. Lock of suitable policy in urban development controls and land management, caused that the Tabriz faced whit many challenges. One of these chalenges is the lock of public land use. So,in this paper, accessibility of urban public land uses in Tabriz is analysed. Methodology in this paper is practical and the surviving method based on descriptive – analytical method. In surviving and analyzing of public land uses, we used per capita and Taxonomy methods. For necessary surviving, statistical blocks information and urban land use map for Tabriz city are used. Results show that the public land use per capita is less than 8 meters, while in master plan of Tabriz; this per capita has proposed 16.71 meters.So, the availability of public land use has critical condition in Tabriz. Green space per capita in all of zones is faced with shortages and the reason of these shortages is the lock of suitable planning for urban expansion. This lock caused that the gardens and green spaces in the periphery of Tabriz are demolished.
For analyzing of urban public land use allocation in this paper, Numerical Taxonomy is used.The results of Numerical Taxonomy show that district of number one is the best degree (0.30) and district on nine is the worst degree (0.83) for accessibility to public land use.

Immigration and the growth of metropolitan areas are always associated with major changes in the areas around them. National Tehran metropolis with its rapid growth in recent decades has caused population increase and physical development of the surrounding towns and villages. The aim of this study is to investigate the factors affecting demographic and physical changes in Garachak city as a settlement around Tehran metropolis. The research method is descriptive-analytic and data collection was based on library documents, observation, in-depth interviews and 300 household questionnaires completed randomly. The data were analyzed by using single T- test, multi-variable regression, interpretation of satellite images (in years 1987 and 2011), and Holdern model. The results showed that due to reasons such as locating on Tehran-Varamin road, short distance and the rapid access to metropolis ​​Tehran and its facilities, and also due to the low costs of land and housing in that area, Garachak city has had high population growth so that the city as a complementary area for Tehran has an additional role in residency and settlement. According to Holdern model analysis, approximately %68 of physical growth and nearly %32 of growth in Garachak city is respectively associated with population growth and horizontal-sprawl growth which have caused huge changes in economic, social, and ecological aspects of the city.

With The wave of industrialization to the third world, production and income and consequently demand for municipal services. From the early twentieth century, has increased. This trend raised the number and size of cities in these countries and led to urbanization and. So cities were encountered with specific problems. Cities Physical development and urban population growth and subsequently changes in physical and spatial development of cities to become a problem or issue in recent decades. And attention to urban issues - particularly the physical issues - in the form of a scientific framework is the importance and necessary. Babolsar city with having a natural, tourism, academic attractions and ... has grown as one of the main poles of attraction of population in the Mazandaran province, in recent years. This trend of population growth and Entry Immigration and tourism led to the construction without plan and large change in the space - physical structure of city and its development in the coastal strip and surrounding agricultural land.
Research Methodology depends on the purpose and nature of its research and administrative facilities.
Thus, the approach of this research is field, library and descriptive - analytical.
Data and information needed to research has been taken from field and processed. So, after select the topic, at first with examining documents and library data bank Online, physical development and population trends of Babolsar in different periods of history was determined. After collecting the required data, with relying on the information obtained, the physical development and population trends of Babolsar in different periods of history was determined. After collecting the required data with relying on the information, obtained the physical development and expansion of Babolsar city with use of Shannon`s entropy and holder models. But the main research approach has been based on descriptive- analytical methods.
Today, knowledge of space form of city can be one of the most important affecting factors in success rate of urban planners to meet the needs of present and future, In this paper have been helped two models: Shannon`s entropy model to analyze the physical development of Babolsar City in 1379 and 1389 which are respectively 11 and 22 quarters (Map 3),
Shannon`s entropy model: we use this model to analyze the Ugly urban growth phenomenon. The overall structure of this model is as follows:
The results found that amount of entropy in Babolsar city was 20166 / 2 in 1379. While the maximum value is Ln (11) = 2 / 3978 is Can be mention to being close the amount of entropy to maximum amount (2 / 3978). This issue represents dispersed (sprawl) the physical expansion of the city. 11 neighborhoods of the city were separated into 22 neighborhoods in 1389. The estimated amount of entropy is calculated equal to 94214 / 2, while the maximum value isLn (11) = 3 / 0910 that it shows, the physical expansion of the city, was scattered over the past ten years.
Holdern model: Results of the Holdern model about the Babolsar city shows that within the 1385-1335 years About 60 percent of physical growth, population growth related to population growth and 40 percent of physical growth was related to horizontal growth and urban sprawl that it`s result was decrease density Gross population and increase of Per capita net urban land and eventually ugly Horizontal spread (sprawl) of Babolsar city.
In this paper has been discussed and analyzed pattern of physical development of city in different periods and with use of related models. the amount of Shannon`s entropy of Babolsar City showed diffuse growth (sprawl) in 1379 and 1389 that led to destruction of part of quality agricultural land. In survey of appropriateness of the size of the city’s development with population during the decade (1385-1335) with Holdern model came to the conclusion that About 60 percent of the city expansion was consistent with population growth and 40 percent of physical expansion, was due to Ugly urban growth and inharmonious (sprawl) of city. This is the result of uncontrolled urban growth And not having a written plan for the physical development of city. Population growth and limitless expansion of the nearby city of Babolsar, Cause excessive pressure on water resources and other infrastructure, the destruction of good agricultural land around the city and has many other issues. We found out that something's helps city to prevent uncontrolled physical expansion; can be developed within the context of the city, expansion the culture of vertical wings the city, and eventually Providing facilities in the villages to prevent migration of villagers to the citys.