Naser Shafiei Sabet; Faranak Feyzbabaei cheshmeh sefidi
Abstract
Introduction: Land use change is spreading in developing countries and has negative environmental-ecological consequences. Therefore, access to up-to-date information on land-use change is necessary to analyze the needs of human settlements and adopt appropriate policies that are essential to ensure ...
Read More
Introduction: Land use change is spreading in developing countries and has negative environmental-ecological consequences. Therefore, access to up-to-date information on land-use change is necessary to analyze the needs of human settlements and adopt appropriate policies that are essential to ensure the future. The study of past, present, and future land use has a fundamental role in the decisions and policies of land-use planners. This study aimed to study land use and its changes during 1993, 2004, and 2019. The CA-MARKOV model also identifies how land-use changes in Hamedan and simulates and predicts land use and its changes in 2050.Material and methods: In this study, after obtaining satellite images of TM, ETM, and OLI sensors, preprocessing steps including various radiometric and geometric corrections were performed on the images.Then, the classification of satellite images was done using Google Earth software and the vector support algorithm. Based on this, the land uses of the region were divided into four classes: residential and non-residential use, barren lands and poor rangeland, garden lands and irrigated agriculture, and mountainous and rangeland. After land use detection and its changes, the trend of these changes was predicted in 2050 using the automatic cell model and Markov chain due to its high ability to detect spatial-spatial component changes.Results and discussion: Results indicated that the growth and development of urbanization in this metropolis have led to the city's expansion in this area. So that residential and non-residential land use increased from 0.8% of the total area in 1993 to 2.1% in 2019. The study of land-use changes showed that from 1993 to 2004, 0.2% was added to the rate of residential and non-residential land uses. The next largest increase in land use was in the very poor barren lands and rangeland, which reached 49.8% in 2004. Horticultural and irrigated agriculture land use and mountainous land use decreased by 1.2 and 1.5%, respectively, in 2004 compared to 1993. The land-use area of residential and non-residential construction and barren lands have continued to increase in 2019. The area of these land uses increased by 1.1 and 2.4 %, respectively. Finally, it can be said that from 1993 to 2019, horticultural, agricultural, mountainous, and rangeland uses have been transformed into residential and non-residential construction uses and barren lands. This land conversion has negative consequences for the region's future.Conclusion: In this study, it was found that the automatic cell model and Markov chain have a high ability to predict future land-use changes. Also, the largest increase in land use was related to residential and non-residential construction and barren lands, and other land uses such as garden lands and irrigated and mountainous agriculture. Rangeland experienced a decrease in area in the region. Therefore, planners should consider this extensive urban growth and development to carry out their plans more efficiently.
ِ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.
