Mohammad Taghi Razavian; Ali Rahimi
Abstract
Introduction: Nowadays, the urban sprawl phenomenon has become one of the most important concerns of planners and policymakers. The lack of attention to this phenomenon has led to irreparable consequences such as threatening natural resources, and social, economic, physical, and environmental constraints ...
Read More
Introduction: Nowadays, the urban sprawl phenomenon has become one of the most important concerns of planners and policymakers. The lack of attention to this phenomenon has led to irreparable consequences such as threatening natural resources, and social, economic, physical, and environmental constraints and disadvantages. In order to better understand such a model, it is necessary to evaluate and identify the socioeconomic factors affecting it. Material and methods: The methodology in this research was a combination of descriptive and explanatory research, the type of research was applied, and its approach was considered quantitative and qualitative. Data collection was done using library and field survey methods. Also, remote sensing and Landsat satellite images of the studied area during the mentioned period was used. In addition, to analyze Zanjan’s urban sprawl, the method of classified classification, land use classification and cross-feasibility model, the extent of changes in different land uses, and the Holdern model were used. In order to predict the trend of changes and to investigate possible changes in land uses for the 2026 horizon, the Markov chains model was used. Results and discussion: In the studied area, the results of the research indicated that over the past three decades, with uneven development in Zanjan City, the urban area has almost tripled. Theoretical analysis of Zanjan’s urban sprawl according to Heldern model indicated significant urban sprawl domination in the physical development of Zanjan, which always had more effect than the population growth. During the studied years, Zanjan’s urban area had a multiplier increase that in contrast to this expansion, had a significant decrease in orchards and agriculture. In this situation, what made a big difference were the changes in orchard and agricultural land uses. Translation errorThere were many factors involved in this matter, most notably the growth of urban population and urban sprawl. Conclusion: Based on the forecast for 2026, the probability of land use changes to the city over the next 10 years is significant, during which Translation errorthe amount of built-up areas in Zanjan will reach 6311.88 hectares. It should be noted that orchards and Translation erroraaaagricultural lands have only a 23.56% possibility of conversion to urban areas. Therefore, necessary actions are required to prevent over-urbanization. In developed countries, considering the importance of sustainable development, environmental protection and the efficient use of various sources, smart growth, and urban development are highly important. Moreover, preventing the excessive growth of the city's boundaries, the high-ranking agenda, and the use of the compact city pattern, as well as the direction of the expansion of the city towards regolith and abandoned lands with the aim of preventing constructions in agricultural land can be considered.
ِAshkan Mohammadi; Naser Shafiei Sabet; Alireza Shakiba
Abstract
Introduction: One of the major implications of accelerated urbanization is the spatial expansion of urban sprawl and the corrosive of villages and peripheral lands that have been numerous in metropolitan areas. The irregular sprawl and extension of the Tehran metropolis into surrounding areas have led ...
Read More
Introduction: One of the major implications of accelerated urbanization is the spatial expansion of urban sprawl and the corrosive of villages and peripheral lands that have been numerous in metropolitan areas. The irregular sprawl and extension of the Tehran metropolis into surrounding areas have led to disturbances and imbalances in the social, economic, and spatial organization of peripheral villages. In recent decades, urban growth analysis has started from a variety of perspectives. Over the past half century this phenomenon has been prominent in Iran. It originally took place in metropolises and large cities, but gradually moved to middle cities due to the centralized policies of the settlement .The study area has been expanding rapidly in the last three decades and has caused many environmental problems and rapid changes in the economic performance of villages and the transformation of valuable natural resources. Therefore, this research intends to investigate the manner and extent of land use changes in the study area by analyzing and accurately analyzing the phenomenon of creep and reducing the adverse effects by providing scientific solutions. Therefore, this research is intended by look up and accurate analysis of the sprawl phenomenon, study the method and extent of land use change in the study area and reduces its adverse effects by providing scientific solutions. Material and methods: For accurate analysis of the effects of sprawl phenomena, descriptive and analytical methods have been used. In this method, after collecting data contains Land sat satellite images with TM, ETM and OLI sensors and after visual interpretation of satellite images due to the absence of stroke errors, cloud spots by using remote sensing techniques and spatial information systems, the land use change process began in 1986, 2002, 2018, and divided into four residential and non-residential construction, vegetation, rangelands and roads. After that, the supervised classification operation was monitored by the SVM algorithm and the detection and determination of the sprawl pattern in the study area. Results and discussion: The calculations indicate that in the region of Tehran -Damavand, due to the crawling growth in discrete form and in some points continuous, the most changes in terms of increase is related to the use of residential construction 9.69% and the use of the road 1%, that this growing trend has reduced the use of pasture and vegetation by about 9.07% and 0.1%, respectively. After field operation and harvesting of samples with two-frequency GPS receivers and introducing it to the software, the classification of complications was performed by support vector machines with a mean total accuracy of 62.69% and a mean Kappa coefficient of 85.33%. Most changes were related to residential and non-residential classes and roads and in the study area, most vegetation coverings and agricultural land became industrial estates and recreational villas. This led to an increase the migration from villages to Tehran's metropolis, followed by the need for urban landscapes and finally fragility and instability of environmental resources. In Tehran- Damavand axis, these changes have been made by various factors and forces during its uneven spatial expansion. Conclusion: In the study of spatial and land use changes, it is important to pay attention to which side effects are slowly changing and which side effects change more quickly. In this research, it was revealed that the study of vegetation compared to other lands had the greatest change. Therefore, if there is no precise planning and policies and continuous monitoring to prevent this trend, there will be harmful and irreparable environmental impacts.
Naser Shafiei Sabet; Sogand Khaksar
Volume 15, Issue 3 , October 2017, , Pages 55-74
Abstract
Introduction:
Imposition by cities of new roles and functions on peripheral areas has provoked economic, social and spatial disturbances in those areas (Shafiei Sabet & Bozorgniya, 2013). In this regard, major global trends that have fuelled competition over land have also contributed to the development ...
Read More
Introduction:
Imposition by cities of new roles and functions on peripheral areas has provoked economic, social and spatial disturbances in those areas (Shafiei Sabet & Bozorgniya, 2013). In this regard, major global trends that have fuelled competition over land have also contributed to the development of urban imbalance (Ludlow, 2014). As a result of population density and pressure on resources in cities with rapid expansion, the environment is adversely affected with detrimental impacts on valuable agricultural land. In this regard, Karol argues that ‘urban spraw’ was not problematic at its outset, but the positive effects of this phenomenon are long gone (Lawrence, 2012). Industrialization of the economy has turned villages around cities into unplanned spaces (Deep & Saklani, 2014). This phenomenon raised concerns in connection with the metropolis and the main cities, but the gradual adoption of centralized housing policies and development approach by the state at the regional and local levels contributed to the this issue affecting the middle cities as well (Shafiei Sabet and Haratifard, 2011). Based on this, the present research intends to analyze this phenomenon accurately to help find solutions to mitigate the adverse effects by providing scientific solutions to reduce the damage caused by it in the studied area.
Materials and methods:
A descriptive-analytical method was used to measure accurately the consequences of urban sprawl in the study area. To this end, based on analysis of satellite imagery using Remote Sensing (RS) and the Geographic Information System (GIS), the land use change trends during the three periods of 1990, 2006, and 2015 were investigated for different land uses (residential construction, non-residential construction, changing arid land, agricultural land, gardens, pastures and roads). Then, the effects of urban sprawl on rural settlements around the city of Hamedan and its determinants were investigated. The data collection included the survey of Land sat TM satellite images in 1990, ETM + 2006, HRVIR 2015, and a 1: 50000 map of Hamadan Province for the enhanced detection of phenomena and their comparison with land use changes in subsequent periods.
Results and discussion:
The results suggest that, in Hamedan Province, the urban development and dispersed sprawling growth of the city has caused the highest rate of land use change in agricultural lands over a 27-year period, from 1990 to 2015. As a result, these lands have seen a decrease of 1017 hectares over this period and, at the same time, horticultural lands have also diminished by about 272 hectares. In the meantime, rangelands have dwindled by about 189 hectares. By contrast, residential construction increased by 805 hectares in 2015 compared to 1990, followed by an increase of 346 hectares in non-residential construction and 20 hectares in route and road construction. Moreover, an area of 307 hectares from the total area of 6446 hectares in the study area has been transformed into desert land, and therefore the scene of various construction activities. A comparison of the statistics suggests that residential construction continues to grow, so that the statistical results of three periods indicate an increase of about 17.8% in construction the study area from 1990 to 2015. According to the results, it can be seen that in current situation of Iran, the research undertaken on the marginal area of Hamedan is consistent with the researches of Yagre, Ewing, Morot and Hernandez and other researchers who have discussed environmental issues and the lack of supportive policies to impede the spread of these structures in Europe.
Conclusion:
In studies on spatial development and land use change of agricultural lands, it is important to note the parameters that undergo change progressively as opposed to those that change more rapidly. In this study, it was found that in the study area, farmlands (agro-horticultural lands) have undergone the highest change compared to other lands. Therefore, if policies and measures are not taken to prevent this trend to continue, the environmental damage will be caused by pressure on resources, conversion and land use change, resulting in the destruction of valuable agricultural land.
