ٍErfan Khodaparast; Fatemeh Eshaghi; Hassan Darabi
Abstract
Introduction: Landscape as a whole is the reflection of the structure and function, and their interaction. Although, metrics of landscape ecology provide an appropriate tool to analyze the structure and function of landscape, deep understanding is needed to perceive the generality and evolution of the ...
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Introduction: Landscape as a whole is the reflection of the structure and function, and their interaction. Although, metrics of landscape ecology provide an appropriate tool to analyze the structure and function of landscape, deep understanding is needed to perceive the generality and evolution of the landscape as a whole. This is especially important for urban landscape interpretation. In particular, when urban development is the result of spatial development which is mainly influenced by socio-economic processes. As a result, the environmental context is less considered. Disturbance in the natural and ecological structures is the consequences of such process that leads to the ecological rupture of the landscape. Accordingly, structural changes affect the functioning of the city's natural ecosystems that make cities more unsustainable. Hence, it seems that the first step in improving the current situation is to explain the pattern of landscape changes appropriately and provide an understanding of the effects of urban development patterns of the ecosystem. Accordingly, the purpose of this study is to evaluate the overall landscape changes of Qom over 30 years.Material and methods: Therefore, an was made to first, compute the structural and functional changes in the landscape by using landscape metrics. Therefore, the natural and artificial structures that make up the city's landscape were extracted from the US Geological Survey (USGS) using satellite images. Images were taken in 1989 from the Landsat Satellite 5 (TM), in 1999 and 2009 from the Landsat 7 (ETM), and in 2019 from Landsat 8 (OLI). Then, it was classified by Supervised Classification method and Maximum Likelihood using the ENVI software. The natural and artificial structure was classified into four categories: vegetation, building, communication, and bare lands. Then, ten appropriate metrics were calculated to quantify the changes in the four aforementioned categories. The essential calculations have been done by the Fragstats software.Results and discussion: The results of the study showed the uninvited and accelerated changes in the ecosystem of the Qom base on the application of landscape metrics. Qom has experienced serious structural and functional changes over 30 years. The man-made landscape is developing at the expense of devastating natural structures and natural patches are disappearing. On the other hand, the introduced patches are increasing progressively. However, introduced patches did not have a significant effect on the overall trend of landscape change. Examining the trend of LPI, AREA-MN, SHAPE-AM, and SHAPE-MN indicators provided information about changes in the visual form of the landscape. The increase in artificial patches, along with the lessening of the largest desert patches to one-third, indicated the emerging of progressive fragmentation in the desert landscape of Qom. Meanwhile, the shape of the city is changing into a simple geometric pattern, which means the loss of natural ecosystems. The status of the indicators during different years expresses the simplification of the urban landscape. The result is multiple effects on the urban environment, such as changes in microclimate and its consequences on the fragile desert ecosystem.Conclusion: It is necessary to revise the development model and consider serious attention to natural-oriented approaches while responding to human needs in such areas. It seems that the present model of ecological planning along with strategic proposals is obligatory to practice the ecological-based projects for future developments to enhance the quality of Qom’s ecological landscape.
Parastoo Hassanpour; Romina Sayyahnia; Hassan Esmaeilzadeh
Abstract
Introduction: Urban green space, as an important part of the urban complex ecosystem, offers many ecological, social, and economic services that contribute to the quality of life in cities. Today, the rapid growth of urbanization, along with a lot of changes in land cover and land use, has caused many ...
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Introduction: Urban green space, as an important part of the urban complex ecosystem, offers many ecological, social, and economic services that contribute to the quality of life in cities. Today, the rapid growth of urbanization, along with a lot of changes in land cover and land use, has caused many environmental impacts associated with a reduction in green spaces and, as a result, have negative environmental impacts. Accordingly, the purpose of this study was to investigate the trend of changes in the extent and structure of green spaces in the 22nd district of Tehran from 1996 to 2018 with the landscape ecology approach. Material and methods: One of the principles of the ecology of the land is to examine the changes in land use and land cover over time. Accordingly, in the present study, using LANDSAT satellite imagery from 1996 and 2018, landslide maps of Tehran’s District 22 were first developed in four classes including man-made, green spaces, open spaces, and water patches. In the following, the selection of landscape metrics at the level of the landscape including normalized entropy, relative richness, edge density, patch area, patch compactness and class-level metrics including the number of patches, edge density at the class level, mean patch size, and mean shape index were analyzed for landscape analysis. Results and discussion: The findings reveal that green areas of zone 22 of Tehran in 2018, in aspect of cohesion, size and shape, structurally have been changed rather than 1996, and don't have desirable situation, because the structure of urban green spaces have been diminished. Namely, two type of basic changes have been occurred in ecological landscape, includes developing new polygons and segmentation of polygons. Conclusion: The findings of the research indicated that green patches in the district 22 of Tehran, in comparison with previous years, in terms of number, area, size and shape have undergone major changes and are not in a desirable condition, because the structure of urban green spaces have been fragmented. Accordingly, suitable spots for the development and improvement of the continuity of urban green patches were presented.
Vahid Nasiri; Ali Asghar Darvishsefat
Volume 16, Issue 3 , October 2018, , Pages 101-118
Abstract
Introduction: A landscape is a heterogeneous and vast region consisting of a set of patches, habitats, and repetitive environmental elements. In recent studies, various metrics have been used to investigate the structure, function, and landscape pattern changes. The metrics are quantitative indices that ...
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Introduction: A landscape is a heterogeneous and vast region consisting of a set of patches, habitats, and repetitive environmental elements. In recent studies, various metrics have been used to investigate the structure, function, and landscape pattern changes. The metrics are quantitative indices that describe the structural and spatial properties of the landscape. The objective of this study was to obtain information on the current status of different land use classes and the analysis of complex relationships among classes in Arasbaran region. Material and methods: In this regard, a land use/land cover (LULC) map with seven classes (i.e., high-density forest, low-density forest, agriculture, grassland, barren land, water, and urban area) was produced from Landsat 8 OLI imagery (2014) and ancillary data. Eighteen different landscape metrics including area metrics, shape metrics, isolation and proximity metrics and diversity metrics were calculated for each class and landscape level. Results and discussion: Results showed that the high-density forest and grassland form the main elements of Arasbaran landscape with 30.76% and 30.03% of the Percentage of landscape, respectively. The metrics of number and density of patches showed that grassland and low-density forest classes had the highest number of patches compared to other land use classes and so are the finest grained land use classes in the area. The largest patch index also showed that 4.76 percent of the landscape was occupied by the largest high-density forest patch. The total edge and edge density indicated that the majority of the area is covered by high-density forest and it provides the longest border with other land uses. Based on the shape metric, urban area and barren land have the most dispersion. In addition, the urban area and high-density forest are the most discontinuous and continuous land uses in the landscape, respectively. Based on the mean of Euclidean distance, the distance between the high-density forest patches is the minimum and the distance between the urban patches is the maximum metric. In total, the study area is composed of 802 LULC patches. Also, based on Shannon and Simpson diversity and uniformity metrics, the area is diverse and heterogeneous. Conclusion: Considering the fine-grained grasslands and forests with high (dis) connectivity, the dispersion of urban areas, and the extent of agricultural lands, an increasing rate of changes in the land use can be estimated in the future. The future changes can be as removing small patches of grassland and forests, and expansion of the urban and agricultural classes.
Sara Abbaszadeh; Shahindokht Barghjelveh
Volume 16, Issue 3 , October 2018, , Pages 181-202
Abstract
Introduction: The paradigm of “Ecology in City” became an active approach in the early 1950s in Asia and Europe. In the paradigm of “Ecology of City”, the planning process of solving the urban landscape systems’ complex environmental problems relies upon a comprehensive ...
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Introduction: The paradigm of “Ecology in City” became an active approach in the early 1950s in Asia and Europe. In the paradigm of “Ecology of City”, the planning process of solving the urban landscape systems’ complex environmental problems relies upon a comprehensive knowledge of ecological principles and of ecological networks. As in the process of planning the urban landscape systems’ ecological networks, the physical system of urban structures has a quadruple characterization of ecological heterogeneity: “structural”, “procedural”, “temporal” and “spatial”, it characterizes that in the study of urban planning there is a need for a deeper knowlwdge of urban structures and of ecological networks they provide. Overall, the urban structures’ ecological networks provide a physical system for the flow of mater, energy and information. On the other hand, “urban ecology” merely adds an emphasis on human ecosystems in general, which include organisms, the physical environment and conditions, the human population and its social structures and processes, and the built and technological components. Therefore, the main objective of this research is to apply the principles of landscape ecology and of ecological networks in the process of planning the urban landscape systems’ physical structures. Material and methods: The methodology of this research is divided into two main sections:1) analyzing the conceptual framework of the research in explaining the structural planning of ecological networks, and 2) programming the physical structure of Tehran's landscape system in coordination with the ecological trends of its landscape system, and the management system of the desired changes in the structural pattern of ecological networks. In this research, we used the LCM model (Land Change Modeler), which depicts the modeling of the changes in urban land use from the past to the present and future, and GIS (Geographic Information System) software. Results and discussion: The damage to ecological networks has caused a dam in biological processes and loss of cycles of matter and energy in the creation of eco-sociological landscape systems. This eventually has led to simplification, fragmentation, and deficiency of urban landscape systems, resulting in negative effects on the level of coordination between the four aspects of heterogeneities and their impact on human health and the environment. The generated maps in three consecutive times indicate a significant decrease in vegetation cover and landscape fragmentation in Tehran's physical system and, consequently, an increase in the magnitude of manmade structures during urban development processes, especially in the next ten years. In this regard, two issues have been considered: 1) establishing an analytical relationship between the research’s proposed conceptual framework and the data obtained from the physical system of Tehran's landscape system, and 2) analyzing the current trend of urban changes, predicting the effects of the city's physical development on local ecological networks, and the proper planning of changes for the structural pattern of Tehran's physical system. Conclusion: The analysis of Tehran’s landscape system is based on a framework proposed by current research’s conceptualization of three scientific approaches, including: “biology”, “ecology”, and “landscape ecology”. In addition of clarifing the living process of an urban landscape system’s “biological”, “social” and “spatial” characteristics, it takes into account the process of planning urban ecological networks, based on an applied strategies in reducting the ecological disturbances of Tehran’s urban landscape system.
Majid Ramezani Mehrian; Shahrzad Faryadi
Volume 12, Issue 2 , July 2014
Abstract
Connectivity is one of the most important characteristics of urban green network and its necessary to enhance efficiency of landscape and biodiversity. Hence, urban green space designers need a tool to analyze and optimize the connectivity of green networks. Concepts of graph theory can be used to simulate ...
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Connectivity is one of the most important characteristics of urban green network and its necessary to enhance efficiency of landscape and biodiversity. Hence, urban green space designers need a tool to analyze and optimize the connectivity of green networks. Concepts of graph theory can be used to simulate and analyze of green networks and develop a plan prepared for improving efficiency and biodiversity. In this paper, potential corridors were determined for connecting the main green patches of district 1 of Tehran using shortest path analysis. Then, using network analysis and principles existed in graph theory and gravity model, an optimized plan was developed for urban green space network of this area. Results indicated that network analysis provided high efficiency in modeling, analyzing and optimizing of the urban green space network. Therefore, in order to cover the deficiencies in urban green space development plans, an appropriate method for increasing network continuity and enhancing the efficiency green space was presented.
Hassan Taghvaei
Volume 6, Issue 1 , October 2008
Abstract
The art and knowledge of landscape architecture spans many disciplines, while landscape design in itself is an expression and treasury of cultural values and beliefs, natural and visual impacts. In the case of ecological and environmental paradigms and knowledge,the designed landscape faces particular ...
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The art and knowledge of landscape architecture spans many disciplines, while landscape design in itself is an expression and treasury of cultural values and beliefs, natural and visual impacts. In the case of ecological and environmental paradigms and knowledge,the designed landscape faces particular challenges to environmental design quality and landscape identity. This threat is even more significant for a country like Iran with considerable ecological diversity and an ancient civilized culture. This paper addresses the potential contribution of both of Iranian tacit knowledge of landscaping and landscape ecology to manage, or at least help alleviate, some of these issues. The key questions are: ∑What new challenges are there in landscape design related to landscape ecology? ∑What concepts and values can help us create a fit and beautiful landscape with environmental benefits, while making use of vernacular potentials? ∑How can various aspects of knowledge influence the way we design, construct and manage landscape and develop urban and rural landscapes architecture? In an effort to answer these questions, we hope to identify measures for appropriate choice of vegetation; appropriate grading; use of barriers; and the promotion of environmental archetypes, native methods and ecological patterns. In order to cover these delicate discussions, the author presents two main concepts tacit environmental knowledge and the oasis paradigm.
Nooshin Khazaei; Forod Azary Dehkordy
Volume 4, Issue 4 , July 2007
Abstract
Restoration is to decrease human impact on ecosystems, and let them to recover. In this method we can connect patches with corridors. Thus, to introduce an ecological restoration we considered shafarod watershed with 39800 ha, that is located in Gilan province. Corridor recognized as a liner element ...
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Restoration is to decrease human impact on ecosystems, and let them to recover. In this method we can connect patches with corridors. Thus, to introduce an ecological restoration we considered shafarod watershed with 39800 ha, that is located in Gilan province. Corridor recognized as a liner element of landscape, which can connect patches. The objective of this research is to introduce a new method for ecological restoration of forest by using landscape ecology approach. At first we classify patches with Forman (1995) on basis of natural or man made. Then each patch on shafarod landscape was classified with, near to river or far from road, and with area, then each patch had one code that tell us the situation of road and river related to each patches. Patches with upper than 1 hectare are suitable for stepping-stone patches. In shafarod watershed among 683 patches with36200ha, 56 patches with 228ha for restoration had been recognized and total area that these patches need to create corridors for restoration is about 62ha. Keywords: restoration, landscape ecology, corridor, stepping-stone, Shafarod
