Urban Ecology
Hassan sajadzadeh; fatemeh ghorbanileylestani,
Abstract
The Effect of Vegetation on Reducing the Urban Heat IslandCase Study: Karaj CityIntroductionWith the rapid growth of population, urbanization is gaining momentum where urban areas are developed with greater proportion resulting into changes in existing landscape, buildings, roads, and other supporting ...
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The Effect of Vegetation on Reducing the Urban Heat IslandCase Study: Karaj CityIntroductionWith the rapid growth of population, urbanization is gaining momentum where urban areas are developed with greater proportion resulting into changes in existing landscape, buildings, roads, and other supporting infrastructure. Such a change replaces open land and vegetation in the form of permeable surfaces with concrete surfaces which are impermeable and dry in nature.The consequences of population growth and urbanization on the urban environment, climate, and water supply have caused a wide range of issues. One of the key impacts of rapid urbanization on the environment is the effect of urban heat island (UHI). Such a development leads to the formation of urban heat islands whereby urban regions experience warmer temperatures than their adjacent rural surroundings.Urban Heat Island (UHI) is a growing problem worldwide and increase in the land surface temperature and the formation of heat islands in the metropolis ar n recent years, various studies continuously manifest that the increased ambient air temperature in cities caused by UHI phenomenon embraces enormous negative influences on social, environmental and economic dimensions of cities eas has become one of the environmental problems. The heat island affects the quality of urban life, including energy consumption, air quality, as well as human health.Strategies to mitigate the Urban Heat Island represent an important objective in design and urban planning, especially in cities in hot climates. Mitigation of UHI is necessary for cities to adapt to climate change and enhance sustainable development at a city scale. Cooling cities with urban vegetation management is a sustainable solution for urban heat mitigation and to increase thermal comforts of urban residents. Materials and MethodsRemote sensing is a powerful tool for environmental monitoring that can be used to help understand LULC and rapid urbanization and to estimate UHI and ndvi properties at the Earth’s surface.The present paper, Land cover maps within the administrative boundary of karaj city were derived from the cloud-free Landsat (downloaded free from http://www.usgs.gov/) with a resolution of 30 m for the years 2001-2021. at first 2 images of the warm seasons of the year from 2001-2021 were extracted from Landsat satellite including Landsat 7 (ETM+), Landsat 8 (OLI/TIRS) sensors. After the necessary pre-processing, land surface temperature (LST), and normalized difference vegetation index(NDVI) land use patterns were calculated for monitoring the land use changes in karaj. The land covers were classified into three types (built-up land, vegetation, and barren land) using the maximum likelihood classification approach.Therefore, the present study explored the relationship between LST and NDVI Karaj region of alborz. The relationship of LST with NDVI was examined using correlation analysis. We used a regression tree model to examine the nonlinear relationships between LST and normalized differential vegetation index (NDVI).This study focused on tow objectives. Firstly, analyzing land surface temperature (LST), normalized difference vegetation (NDVI) indices. Secondly, investigating interrelationships among LST, NDVI. Finally, the environmental criticality index (ECI) was used to identify and analysis of the sensitive regions.Discussion of ResultsIn this paper, the negative impact of Urbanization over a time and its effect on increasing trend of temperature and degradation of urban ecology was assessed using the Landsat thermal data and field survey of karaj city, alborz.In karaj City, LST showed an increased trend from 2001 to 2021 years, as increase the maximum temperature in the period from 2001 to 2021 was 4 °C, while increase the minimum temperature of 19°C was observed from 2001 to 2021.The result showed that the type of land use had an effect on LST. The results showed that the arid lands around the city have the highest temperature and form very hot temperature areas. The observed results showed that the central portion of the city exhibited the highest surface temperature compared to the surrounding open area, the areas having dense built-up displayed higher temperatures and the areas covered by vegetation exhibited lower temperatures.The highest temprature of studied region is observed around the city due to existence of barren lands and in to the city around the industrial centers, around the airport, passenger terminal, around the metro stations, the highways and streets of heavily congested areas and urban decay context areas. At the same time, analyzing the land surface temperature maps in karaj indicate the areas without vegetation have a maximum LST and areas with high density vegetation have minimum LST.The landuse maps also show the reduction of barren lands, vegetation and increasing the urban landuse. This indicates that the decrease in vegetation cover and increase in urban landuse were the most important factors in development of the heat islands in karaj. Also Land use maps also show a decrease in the area of arid lands and vegetation and increase urban use.The findings show normalized difference vegetation index is strongly correlated with the variations of land surface temperatures. The correlation coefficient between LST and NDVI was negative and inverse. The highest environmental sensitivity was in the East and Northeast parts of the city were identified.ConclusionsThis paper has demonstrated the relationship between urban heat islands and Normalized Difference Vegetation Index in karaj city. Results indicated that the spatial distribution of the land surface temperature was affected by the land use-land cover change and anthropogenic causes.The results illustrated that barren lands surrounding the city in continuous and dense have the largest urban thermal islands and forming very hot temperature limits and in the study area, extreme high-temperature zones were observed, possibly due to dense concrete surfaces.Hence, the development of green roof vegetation and tailored to the indigenous climate is proposed as solution to mitigate urban thermal island and dealing with environmental crisis.Keywords: Urban heat islands, vegetation, satellite images, Karaj
Urban Ecology
najme sadat mostafavi; parvin partovi; Zhara Asadolahi
Abstract
Highlight:
- Urban development plans offer numerous opportunities to incorporate the concept of ecosystem services into the urban planning process, yet their integration remains inconsistent.
- Scientific methods to evaluate the uptake and operationalization of ecosystem services in urban planning ...
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Highlight:
- Urban development plans offer numerous opportunities to incorporate the concept of ecosystem services into the urban planning process, yet their integration remains inconsistent.
- Scientific methods to evaluate the uptake and operationalization of ecosystem services in urban planning include stakeholder interviews and content analysis of plans.
- Analyzing these plans provides a broader understanding of the potential, gaps, and limitations regarding ecosystem services.
- Cultural ecosystem services, followed by provisioning and some regulating services, receive the most attention in these plans.
- The survey and analysis phase, influenced by the scale of service studies, is the primary focus.
Introduction:
Urban areas, as human-environment systems, depend heavily on natural ecosystems for sustainability and well-being. Therefore, integrating ecosystem services into urban planning is essential for promoting sustainable urban development. Among the various decision-making processes impacting ecosystem services in cities, urban planning is arguably the most critical. Despite the increasing academic interest in ecosystem services, there are still significant knowledge gaps regarding their integration into urban planning. Incorporating ecosystem services into the management of urban land is crucial for the rational allocation of land and effective ecological management in urban areas.
However, several obstacles hinder this integration, including the inadequacies in the content and process of urban development plans, the limitations of current planning tools, the lack of knowledge about ecosystem services, the absence of relevant institutions and executive organizations, and the deficiency in the application of ecosystem services knowledge in practice and policy. Moreover, the necessary legal and regulatory frameworks are often lacking. This paper aims to examine both the current and potential utilization of ecosystem services in urban development plans, specifically focusing on the city of Arak.
Methods:
Two dominant scientific approaches are employed to evaluate the uptake and operationalization of ecosystem services in urban planning: interviewing stakeholders and analyzing the content of plans and policies. Content analysis of urban development plan documents provides a comprehensive understanding of the potential, gaps, and limitations related to the inclusion of ecosystem services in urban planning practices. To achieve this goal, a content analysis method with a directional approach (deductive method based on theory) was utilized. The study examined the extent to which 19 ecosystem services were addressed within three components of the Arak development and construction plan: the information base, vision/objectives, and actions.
A scoring protocol was developed to assess the quality of ecosystem services inclusion in urban plans. This protocol used a 3-point scale, with scores ranging from zero (no inclusion), one (implicit inclusion), to two (explicit inclusion).
Results:
Among the regulating services, air purification and local ventilation services were mentioned 109 times, with the highest frequency (34 times) in the analysis section (database). The content analysis revealed that healthy water production was referenced 99 times, while food production was mentioned 82 times. Regarding supporting services, soil quality was noted nine times in total, with the highest mention (four times) in the analysis section. Among cultural services, recreational services and mental experiences were mentioned 94 times, with the highest frequency (26 times) in the city survey and knowledge section.
The results indicate that the ecosystem services concept is partially integrated into the mentioned development document. However, the document lacks a holistic view of urban ecology and its benefits. In the three examined components, ecosystem services were mentioned 607 times, both implicitly (312 times - 51.4%) and explicitly (295 times - 48.6%), with the most attention given to the information base component (358 times - 59%). The significant difference in the score for cultural services (400) compared to provisioning (274), regulating (198), and supporting (30) services suggests that cultural services are more comprehensively included in the Arak metropolis plan.
Discussion:
The inconsistency in addressing each service or concept across the three components highlights a lack of significant correlation between data collection, analysis, goal formulation, vision development, plan preparation, and the establishment of rules and regulations. Another critical issue is the misalignment between the process and content of these plans with new concepts, as well as the weakness of the comprehensive rational process in integrating these concepts. To incorporate new ideas like ecosystem services into urban development plans, not only is there a need to strengthen content and process, but also to improve planning tools. Empirical studies suggest that tools such as Strategic Environmental Assessment (SEA) can help bridge this gap.
Conclusion:
Incorporating the concept of ecosystem services into new laws, guidelines, or revisions of existing plans and programs is a complex process that cannot be accomplished in the short term. The presence of informed stakeholders, public decision-makers, and experts is essential. Additionally, it is crucial to form interdisciplinary teams within both consulting engineering firms that prepare urban development plans and public institutions responsible for drafting and approving these plans. Tools such as Strategic Impact Assessment (SIA) are recommended to evaluate proposed alternatives and select the final options.
Urban Ecology
Elham Ghasemi; Zahra Nazemi; Safoura Mokhtarzadeh; Mahdi Suleimany
Abstract
Highlights:
- Investigates the correlation between environmental factors and UHI intensity in the Isfahan metropolitan area over 10 years.
- Utilizes MODIS Aqua & Terra data alongside Landsat 8 imagery for comprehensive UHI analysis.
- Establishes a significant relationship between UHI ...
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Highlights:
- Investigates the correlation between environmental factors and UHI intensity in the Isfahan metropolitan area over 10 years.
- Utilizes MODIS Aqua & Terra data alongside Landsat 8 imagery for comprehensive UHI analysis.
- Establishes a significant relationship between UHI and urban built density, vegetation, and water features.
- Determines vegetation as the most influential factor in mitigating UHI compared to other elements.
- Highlights the vital role of natural infrastructure in urban planning for UHI mitigation.
Introduction:
The Urban Heat Island (UHI) effect, characterized by a temperature increase in urban areas compared to their rural counterparts, presents considerable environmental challenges, impacting public health, urban energy systems, and city sustainability. This phenomenon, fueled by rapid urbanization and industrialization, exacerbates heatwaves, posing risks to public health. Understanding the UHI effect is essential for developing responsive urban planning strategies both spatially and institutionally. This study, centered on Isfahan, Iran, explores the correlation between UHI intensity and environmental factors, encompassing both built and natural attributes across five scenarios, including four seasons and one analyzing the ambient effect of the ZayandehRud river.
Theoretical Framework:
The UHI phenomenon involves complex interactions among various urban and environmental factors. The density of the built environment contributes to UHI exacerbation through heat storage and anthropogenic heat discharge. Air pollution, especially with greenhouse effects, directly influences heat-trapping and UHI formation. Conversely, green infrastructure and water bodies offer UHI mitigation through cooling effects. This study integrates theoretical basics from urban planning, climatology, and sustainable development for an analysis of how both natural and built elements correlate with UHI intensity in the Isfahan metropolitan area.
Methodology:
A mixed-method approach is adopted to address the multifaceted nature of Urban Heat Island (UHI) and its potentially correlated environmental factors. Land Surface Temperature (LST) data, crucial for delineating UHI, were extracted from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensors onboard NASA's Aqua and Terra satellites, covering a decade from 2011 to 2021. This extended timeframe facilitates the exploration of UHI patterns across various seasons, examining specific impacts during both the flow and dry periods of the ZayandehRud river, as well as distinguishing LST differences between daytime and nighttime periods—unlike Landsat Satellite Images.
Additionally, Landsat 8 images are utilized to process the Normalized Difference Vegetation Index (NDVI) and Normalized Difference Water Index (NDWI) for mapping green infrastructures and water bodies. Air Quality Index (AQI) data from the year 2020 supplements the study, allowing for an investigation into the relationship between air pollution and UHI. The analysis of all datasets employs the Pearson correlation coefficient to ascertain the nature and extent of correlation among UHI and the identified environmental variables.
Results and Discussion:
The findings reveal the persistent prevalence of Urban Heat Island (UHI) during nighttime across all scenarios in Isfahan. However, during daytime hours, the trend shifts, giving rise to cooler zones within the city borders, indicating the emergence of urban cold islands. A noteworthy revelation from the study is the significant exacerbation of UHI attributed to the density of the urban built environment. Intriguingly, air pollution, though exerting a lesser impact on Land Surface Temperature (LST) compared to built density, still plays a role in elevating LST during daylight.
The study underscores the pivotal role of urban green infrastructure and water bodies in mitigating heat islands. Among these elements, green spaces, particularly vegetation, emerge as highly influential, surpassing the cooling effects of both water bodies and polluted air. The seasonal variation in vegetation cover also influences UHI intensity, with reduced vegetative cover in colder, drier seasons contributing to heightened UHI effects. These spatial and temporal dynamics emphasize the intricate balance between UHI and environmental factors, offering valuable insights for decision-makers. Such insights can guide targeted strategies in urban planning and design to address the challenges posed by UHI.
Conclusion:
The study emphasizes the importance of considering UHI in urban planning, design, and sustainability discussions. Strategies include reducing built density and integrating green and blue infrastructures. Addressing air quality and vegetation cover in shaping urban thermal landscapes suggests comprehensive policies. Guarding against UHI through natural space preservation and innovative design solutions tailored to Isfahan's climate can enhance urban livability. Future work should quantify contributions of different elements for comprehensive UHI mitigation models. This Isfahan case study serves as a cornerstone for wider applications across similar cities, aiding in combatting global warming and UHI effectively.
Urban Ecology
mahsa samadpour shahrak; Mehrdad Karimimoshaver
Abstract
Highlights- The research considered the effect of planting patterns on thermal comfort.- The research addressed population increase and its effect on the morphology of cities.- The results of comparison between the scenario without trees and the others demonstrate that the thermal comfort conditions ...
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Highlights- The research considered the effect of planting patterns on thermal comfort.- The research addressed population increase and its effect on the morphology of cities.- The results of comparison between the scenario without trees and the others demonstrate that the thermal comfort conditions exhibit great changes, and all the scenarios create better environmental conditions than the scenario without trees.- The findings show that simply moving vegetation and trees without changing their nature and dimensions and the environment can improve comfort to some extent. IntroductionThe increasing population has changed the morphology of cities and caused changes in the surrounding environmental conditions. Green space per capita is about 4.5 square meters in Iran, which is quite different from the global standard: 20 to 25 square meters per person (Haashemi et al., 2016). As a result, it seems necessary to increase the amount of greenery in cities. Lee et al. (2016) introduce shading and ventilation as the main factors in the improvement of thermal comfort conditions in the environment using trees. Vegetation reduces mean radiant temperature and improves environmental conditions through evaporation and daylight control and reflection (Salata et al., 2017). It plays a major role in the regulation of weather conditions by controlling and conducting wind flow and reducing wind speed and pressure (Perini et al., 2018).Theoretical FrameworkThermal comfort involves conditions of perception in which the surrounding environment is thermally satisfactory (Ashrae, 1997). In their review of the studies conducted in the field of thermal comfort in outdoor spaces, Johnson et al. have introduced the predicted survey average index as one of the most widely used indices among ones such as SET and UTCI. (Johansson et al., 2013). This index has been widely used in different regions with different climates (El-Bardisy et al., 2016; Salata et al., 2015; Abdi et al., 2020).This model was designed by Fanger in 1970, considering factors such as air temperature, average radiant temperature, and relative humidity and two personal variables including clothing resistance and activity level, used as a composite index. This index specifies the coefficients that are measured according to Asher’s thermal scale and indicates the average thermal sensation of a large group of people in a certain space (Fanger, 1970). Therefore, considering and measuring this index causes other microclimatic factors to be taken into account and obtained through the following formulae:PMV=(0.303e-0.036m+0.028)[(M-W)-H-Ec-crec-Erec]E=3.05×10-3(256tsk-3373-pa)+EswEc=3.05×10-3[6.99×5733(M-W)-pa]+0.42(M-W-58.15)Crec=0.0014M(34-Ta)Erec=1.72×10-5M(5867-Pa).The value of H can be measured directly and calculated using the following equation:H=Kcl=tsk-tcl/Icl.Moreover, previous research has pointed out the importance of planting patterns, trees, and vegetation and their impact on the environmental and microclimatic conditions of the region. The question that arises now is what kind of tree planting pattern, among the common ones, can have a better impact on the environment. In this study, therefore, the four common planting patterns of sextuple, quadruple, row, and scattered were selected to be applied in the same conditions and with the same number of trees.MethodologyIn this research, the ENVI-met software was used because the output provides most of the parameters required for thermal comfort, such as Ta, Tmrt, and wind speed (Taleghani et al., 2015), and the results have been validated and used by researchers (Taleghani et al., 2018). For data measurement, five receptors were selected at the central points of the site. These receptors were located so as to be scattered in the site and be capable of expressing the general state thereof. Therefore, three receptors at the central points of the site and two located around the site were selected. Moreover, because the average human height between the positions of sitting and standing is 1.50 meters, the simulation measurement was carried out at this height. The environmental data and information on the receptors were extracted during the study hours (10 am to 9 pm), and the average value was calculated for the predicted survey average index.Results and DiscussionThe analysis of the data and figures extracted from the software demonstrates that a more uniform shade is created in the environment in the scattered pattern than in the others, and because the trees are scattered in most parts of the site, solar access is more limited there than in the other scenarios. Moreover, ventilation conditions are easier in the row pattern than in the scattered pattern, and the warm wind passes through the trees more easily there due to the regular arrangement. Therefore, the best planting pattern is the one that creates the more uniform shade and better ventilation conditions. However, the results of the scattered pattern are the same in most parts of the site, and there is only a little difference between them in some cases. As a result, the scattered and row patterns of tree planting are better than mass planting and concentrated in certain parts of the site.ConclusionThe results of comparing the treeless scenario to the others demonstrate that the thermal comfort conditions change to a large extent, and all scenarios create better environmental conditions than the treeless state. Moreover, because the row pattern exhibits a lower average PMV for most receptors and most hours of the day, it is the best pattern. The sextuple pattern has high indices in most cases, and the quadruple pattern has a similar function to the sextuple one. Therefore, it can be concluded that the row and scattered patterns create better comfort conditions than the others. The results of this research can be used by architects, landscape designers, and urban designers. In this research, different patterns of trees have been compared, so future research can involve comparison of other plantings such as grass and shrubs and of the effects of different planting patterns.
Urban Ecology
pariya dorri; Seyed Mohammad Shobeiri; Mahdieh Rezaei
Abstract
Highlights- Citizens’ environmental literacy greatly affected their environmental awareness and knowledge.- The collective environmental behavior of men was greater than women’s.- There was a significant relationship between awareness, knowledge of concern, and environmental behavior.- There ...
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Highlights- Citizens’ environmental literacy greatly affected their environmental awareness and knowledge.- The collective environmental behavior of men was greater than women’s.- There was a significant relationship between awareness, knowledge of concern, and environmental behavior.- There was no relationship between the indicators of environmental literacy and age.- There was a significant relationship between academic degree and environmental awareness. IntroductionThe issue of social responsibility for the protection of the environment at all levels of the society is explicitly emphasized in Article 14 of the General Environmental Policy of the Islamic Republic of Iran. The city of Mashhad is the second most populated city in Iran after Tehran. A city like Mashhad, with a population of nearly five million people, is typically faced with environmental problems such as extremely high temperature, demanding waste management, noise and air pollution, traffic congestion, water shortage, and drought. Expression of environmental problems is a concern, and requires the cooperation of experts and the public to find solutions. Researchers have come up with a variety of solutions to environmental problems, most of which are technological, but they are interested in changing people’s lifestyles and behavioral solutions today due to the high cost of these projects, because environmental hazards result from human intervention. The present issues can be overcome only through changes in human attitudes and behaviors. Citizens with pro-environmental behaviors feel most responsible for the urban environment and the preservation of its natural, historical, and cultural values. The aim of this study was to investigate environmental literacy and its relationship with background variables and the aspects of citizens’ environmental literacy in Mashhad. MethodologyThis cross-sectional survey adopted an individual unit of analysis. The population involved the citizens of Mashhad in 2021. A sample of size 689 containing residents in the thirteen municipal districts of Mashhad was selected using the systematic random sampling method, and parameters such as citizens’ awareness, knowledge, concern, and environmental behavior were measured as dimensions of environmental literacy. The data collection tool was a questionnaire, which was completed with reference to the respondents. For assessment of its reliability, a pre-test questionnaire was completed by a sample of fifty people for elimination of probable defects and calculation of reliability. A Cronbach’s alpha coefficient between 0.70 and 0.84 indicated the proper reliability of the questionnaire. Moreover, formal validity was used in this study. The hypotheses were tested once the data were analyzed using correlation and comparison methods in the SPSS software.FindingsThe results of this study indicated the high level of citizens’ environmental literacy in terms of awareness and knowledge, while the respondents’ score in environmental concern and behavior was only slightly above average. The respondents’ individual environmental behavior ranged between moderate and high. Their environmental behaviors in the public sphere were significantly lower than average and close to low levels. The collective environmental behaviors of men are greater than those of women, but individual environmental behaviors are greater in women than in men. None of the indicators of environmental literacy was related to age except environmental behaviors. The average environmental behavior index was 3.17 for the 18-24 age group, 3.29 for the 25-44 age group, and 3.31 for the 45-64 age group, and the average environmental behavior index for people aged sixty-five years and older was reported to be 3.32. This indicated that the environmental behavior index increased slightly as age rose. The chi-squared test results demonstrated that there was a significant relationship between citizens’ academic degrees and the environmental knowledge index in Mashhad. In other words, environmental concerns increased as academic degree rose. Finally, there was a significant direct relationship with low intensity between environmental awareness, knowledge, and concern and environmental behavior.DiscussionThe results of the study indicated a relatively poor tendency among the citizens towards environment-friendly behaviors, especially in the public sphere. Although the examined population was mentally concerned about the environment, the concern did not provide them with enough energy and motivation to take an action, for whatever reason. Environmental awareness can change only individual environmental behaviors, which is possible in a small space such as a family and impossible or trivial beyond that. Citizens consider the responsibility of protecting the environment outside their personal spaces, such as a house, car, or workplace, as a responsibility of the relevant municipal institutions, and hardly participate in voluntary activities aimed to protect the urban environment. Therefore, efforts should be made to increase citizens’ environmental literacy, and environmental education should be different for different age, occupation, academic, and gender groups. The capacity of non-governmental institutions to attract participation and cooperation among organizations should be used to promote responsibility in environmental behavior.AcknowledgmentThis article is taken from the doctoral dissertation entitled “Designing and validating a model for attracting public participation in the development of environmental literacy of the citizens of Mashhad”, which down in Payame Noor University of Tehran.
Urban Ecology
Pegah Yadegari; hassan sajadzadeh
Abstract
Highlights
The relative confinement of public open spaces of residential neighborhoods in cold climates plays an effective role in the thermal comfort of users.
Reducing wind speed plays a key role in increasing the thermal comfort of cold climates in winter.
Deciduous trees absorb sunlight during ...
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Highlights
The relative confinement of public open spaces of residential neighborhoods in cold climates plays an effective role in the thermal comfort of users.
Reducing wind speed plays a key role in increasing the thermal comfort of cold climates in winter.
Deciduous trees absorb sunlight during the day and reflect it to the environment in the evening and at night
Introduction
Because of the expansion of cities, it has become highly challenging to modify urban structures to address the drawbacks of the planning and design of open spaces, control microclimates, and improve thermal comfort conditions. Due to their effect on the quality of air in cities, urban microclimates are highly significant, and since urban spaces play an important role in creation of urban microclimates, urban designers and planners have the capacity and means to reduce the negative effects of climate on citizens’ health through implementation of proper designs.
Theoretical Framework
Urban spaces affect their users’ thermal comfort via their design elements. Various parameters can induce micro-climatic changes, such as the geometric patterns, vegetation, natural elements, and construction materials of the open spaces. These elements also play important roles in balancing urban thermal comfort during winter. While the effects of vegetation and geometric patterns on thermal comfort in public open spaces during winter have been studied independently, the cumulative impact of vegetation and geometric parameters during winter in cold and dry climates has not been investigated sufficiently. This article sought to address this shortcoming.
Methodology
The ENVI-met software was used for simulation and comparison of the thermal comfort conditions of the open spaces selected for this study. First, the design parameters of the selected sites were determined via field measurement, and were entered into the software for simulation of the thermal environments. The four climatic parameters of thermal comfort were measured during winter using ENVI-met . Then, a receptor was placed at the center of each selected site for investigation of thermal comfort at the pedestrian scale. Using these receptors, the parameters of space design and their impacts on thermal comfort were studied during the selected season.
Results and Discussion
The changes recorded for wind speed were larger than those in MRT, air temperature, and RH; hence, the differences in thermal comfort at the central points. According to the results, the Kolapa and Kolanj neighborhoods exhibited more favorable thermal conditions due to their higher PET values. Both Kalpa and Kolanj neighborhoods had north-south orientation. This type of orientation provides top-down access to the sunlight during winter. The H/W ratios at the central receptors of the Kolanj and Kalpa neighborhoods were 0.6 and 0.3, respectively. These H/W ratios provided greater enclosure than those of the other neighborhoods. While a H/W ratio less than one can be said to be suitable for cold climates during winter, it can cause thermal discomfort against wind speed if it lies below a certain threshold. This condition was observed in the Kababiyan neighborhood, where the H/W ratio at the central point was 0.13. As a result, the residents have to take protective measures against the winter wind and storms. In addition, dense vegetation caused a decrease in the SVF of the neighborhoods. The neighborhood centers with vegetation exhibited higher MRT values as well. The trees also raised the RH values of the neighborhoods. Because of the dry climate of Hamadan, Iran, vegetation can certainly improve thermal comfort in this city.
Conclusion
Recent climate studies have explored thermal comfort as an important quality of urban spaces. While thermal comfort can be achieved through a decrease in temperature in hot climates (as emphasized by most studies), it requires an increase temperature to provide thermal comfort in cold and dry climates. The presence of Hamadan’s citizens in the urban open spaces of the city always decreases in the second half of the year because of the cold mountainous climate. Limitation in or even lack of thermal comfort is one of the most important reasons for this change. With their high standards of sociability, the centers of the historical neighborhoods of Hamadan have always served as places for social interaction between the residents of the city. Therefore, this study attempted to assess the thermal characteristics of nine neighborhood centers in Hamadan using the notion of thermal comfort and the relevant variables.
Acknowledgment
This article has been extracted from a Master’s thesis in the field of Urban Design entitled Measurement and evaluation of thermal comfort in the centers of traditional neighborhoods with an emphasis on urban geometry and vegetation (historical neighborhoods of Hamadan), defended by the first author under the supervision of the second author at Bu-Ali Sina University.
Urban Ecology
Siamak Shakibaei; Sanaz saeedi
Abstract
Highlightsurban microclimate is one of the factors for public open spaces design in order to achieve environmental comfort.Feelings of satisfaction will occur when a person has reached a relative level of physical and mental environmental comfort.environmental and form factors such as shape of buildings, ...
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Highlightsurban microclimate is one of the factors for public open spaces design in order to achieve environmental comfort.Feelings of satisfaction will occur when a person has reached a relative level of physical and mental environmental comfort.environmental and form factors such as shape of buildings, location, functional, microclimate comfort can be achieved through environmental comfort. Introduction City and climate are two man-made and natural systems that have direct impacts on each other. Insofar as it concerns human comfort, climate is the result of factors such as sunlight, temperature and humidity, wind, and rainfall. The climate of any geographic location has particular suitable conditions, which have limitations in the field of urban planning and design at the same time.The quality of designing public open spaces as resorts for leisure has an important role in the satisfaction of individuals. A basic characteristic of a sustainable urban environment is its compatibility and harmony with the local climatic features. Therefore, it is a basic prerequisite for planning and designing urban spaces to recognize, understand, and control the climatic effects of urban areas, to which special attention needs to be made by urban planners and designers before implementing urban plans and projects. Man’s feeling of comfort in the environment undoubtedly affects the quality of his behavior and activity. Therefore, it has a great effect on the health of people’s bodies and souls to pay attention to their comfort zones in the design of different urban spaces. On the other hand, the range of activity and the extent of flexibility in an outdoor area depends to some extent on its microclimatic conditions, especially the conditions of sunlight and wind speed.Theoretical FrameworkMicro-climate pertains to areas that are surrounded by larger areas with specific climatic features. The combination of building design and the outdoor space between buildings in an urban area leads in some cases to micro-production of urban climates. As a result, the micro-climate is shaped by the climatic factors of the city, which vary over time under the influence of urban factors. With its positive effects on the environment, micro-climate can be used as a tool in urban planning and design. Feelings of pleasure and satisfaction will occur when a person reaches a relative level of physical and mental (environmental) comfort, and is free from limitations. Moreover, environmental comfort is a factor affecting satisfaction due to the climatic hierarchy. However, urban micro-climate is a factor needed in the design of urban spaces and public open spaces for achievement of environmental comfort and satisfaction.MethodologyShohada Square in the city of Mashhad, Iran has lost its environmental comfort as a public open space with a particular spatial structure surrounded by commercial and administrative buildings and faced with conflicts with urban micro-climatic issues. For investigation of Shohada Sq. for creation of environmental comfort aided by urban micro-climate, a questionnaire with closed questions (in the Likert scale) was tested on a sample of 112 people. The research methodology was based on the analytical method supplemented by inferential statistics (confirmatory factor analysis test), analysis with the Sketch software, and final rhino analysis (umi plugin) to demonstrate that the micro-climatic factors are in line with the comfort of the square.Results and DiscussionThe results of this study indicate that Shohada Square is a public open space with a great potential in terms of location. Its environmental comfort has been degraded severely for the citizens and even the pilgrims despite the rich historical background of this space, the profound historical dimensions it has given to the metropolis of Mashhad as a historical cultural document of the city, and its direct relationship with the Holy Shrine. This is due to the lack of a proper relationship between its surrounding construction and the urban micro-climates and the neglection of the field space itself with respect to the micro-climates. All this has turned the square into a dead space.Therefore, it should be stated that achievements can be made via environmental comfort on the basis of urban micro-climate and consideration and promotion of indicators such as the comfort level of the square, the effect of shadows on comfort, the leisure time spent at the square, the impact of the anciency of the square on the willingness to spend time there, the effect of land use on the willingness to spend time at the square, the impact of climate and space size on the willingness to spend time there, the lack of urban facilities to address the sunlight problem, and the desirability of the flooring .ConclusionIn addition to the above, one can consider environmental and formal factors such as the location and shapes of the square and surrounding buildings, the existing functional and business spaces such as the commercial and administrative buildings on the periphery of the square, as a popular destination for the citizens, thermal comfort and indoor air quality, and micro-climate comfort, which can be achieved through environmental comfort.AcknowledgmentThis article has been extracted from a Master’s thesis in the field of Urban Design entitled Design of open public spaces with an emphasis on the effect of micro-urban climate on the environmental comfort of users: The case study of Shohada Square in Mashhad. It has been defended by the first author under the supervision of the second author at the Islamic Azad University of Mashhad.
Urban Ecology
Hassan Mahmoudzadeh; Mousa Vaezi; Maedeh bakooyi; Rahimeh Rostami
Abstract
Objectives The evolution in industry in the eighteenth and nineteenth centuries led to greater human domination of the planet and the environment. In the field of clean environment, urban parks are regarded as an important element in creation of a sustainable city. They provide opportunities in various ...
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Objectives The evolution in industry in the eighteenth and nineteenth centuries led to greater human domination of the planet and the environment. In the field of clean environment, urban parks are regarded as an important element in creation of a sustainable city. They provide opportunities in various areas for instance by improving the environment quality, enabling active and passive entertainment, and creating a beautiful environment. Accordingly, thinkers have considered the strengthening of the relationship between the urban man and the nature as a major way of dealing with the problems of urbanization. Therefore, cities need particular attention today in terms of revival of the urban nature, as presence of the nature in the city, to the necessary extent, and its composition and distribution is a requirement of sustainable development. Evidence from Iran and the area under study in regard to current urban green space planning and design indicates that the idea of ecological design and planning is very weakly treated. Due to the dissatisfaction with the current conditions in the design of urban green spaces as an important part of the city, development of green spaces with high ecological efficiency, significant bioclimatic features in particular, should be considered. Findings In the ranking provided by the TOPSIS method, Elogli Park exhibits the lowest positive ideal (5.41) and the highest negative ideal (13.45), followed by the Shams, Baghmishe, and Eram parks, in that order. This is because the cli coefficient, the negative ideal divided by the sum of the positive and negative ideals, for Elogli Park (15.93) is higher than those for the other parks, assigning it the highest priority in ecological terms among the parks under investigation. The four studied forest parks were classified by ecological indicators using the electric model. According to the results obtained by this method, Elogli Park was ranked first in ecological terms, and the Shams, Baghmishe, and Eram parks were ranked next. A point to be noted concerned the improper conditions of the Baghmishe and Eram parks, the latter in particular, in terms of the indicators, calling for greater attention to these parks. Based on the data on vegetation density, Shams Park exhibited denser coverage than the other parks, followed by Elogli, Baghmishe, and Eram, in that order. The denser the vegetation, the higher the priority of the park, and the better its ecological conditions. According to the three indicators studied in the GIS environment, Shams Park was in better conditions in ecological terms than the other parks. Results The results demonstrated that today’s cities need multi-purpose ecological balancing spaces rather than gardens and lawn. The prioritization of the parks based on cultural criteria indicated that the Eram and Shams parks were in better conditions than Shahgoli and Baghmishe. Physically, Elgoli Park was found to hold the highest priority, followed by Shams, Baghmishe, and Eram, in that order. In environmental terms, the Elgoli, Shams, Baghmishe, and Eram parks were ranked in that order. In terms of access features, Baghmishe and Shams were ranked first, followed by Elgoli and Eram. Finally, Elgoli and Shams were both identified through combination of the maps for all the criteria according to their weights as the best parks in terms of accessibility and cultural, environmental, and physical features. They were followed by Baghmishe Park, and Eram exhibited the lowest score among the parks in terms of the above features.
Urban Ecology
Mostafa Karimi; Samaneh Khosnavaz; Aliakbar Shamsipour; Masoumeh Moghbel
Abstract
Today, urban development and air pollution are the most important issues concerning urban climate that can affect the quality of urban life. Despite the significant progress made in the fuel and engine technology, emission of pollutants in urban environments is still prevalent. As in many other countries, ...
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Today, urban development and air pollution are the most important issues concerning urban climate that can affect the quality of urban life. Despite the significant progress made in the fuel and engine technology, emission of pollutants in urban environments is still prevalent. As in many other countries, the environmental issue is particularly evident in the large cities of Iran such as Tehran, Tabriz, Isfahan, Shiraz, Arak, and Karaj. The rapid urbanization, industrialization, and increasing trend in the use of motor vehicles have caused numerous environmental issues, including the production and distribution of different types of air pollutant, especially in Tehran, the capital. Tehran’s confinement by mountains and meteorological factors such as temperature inversion, the persistence of high-pressure systems with cold air, and local winds exacerbate pollution. Hence, numerous studies have been conducted on air pollution in Tehran. The results have indicated that 73% to 85.5% of the air pollution observed at urban stations is caused by temperature inversions, which are influenced by high pressure and surface radiation. According to the above research, the key factors involved in the spread of pollution over the streets besides the spatial and natural factors that can affect the distribution of air pollutants (i.e. geographic location, topography, etc.) include the arrangement of the buildings, particularly in terms of street width and orientation, distance, and intersections. It should be noted given the significance of the issue that the pollution can have extensive effects although it occurs at the street level, due to the interaction of the dispersal and diffusion of pollutants through meteorological conditions (wind speed and direction and atmospheric stability), the configuration of buildings, and the orientation of streets. Therefore, the main purpose of this research was to specify the characteristics of pollutant flow and dispersion on urban passages in micro scale. For that purpose, the meteorological data, including air temperature, relative humidity, and wind speed and direction, were extracted from Iran Meteorological Organization (IMO) Geophysics Weather Station (the closest station to the area under investigation) for a 20-year statistical period (1991-2010). Two areas (1 and 2) in Municipal District 6 were specified as making up the area under study in this research. Then, the pollutant dispersion data were obtained based on the relationship between traffic volume and pollutant production during two winter and summer months (July and January) and at three times of the day (morning, midday, and afternoon). Finally, the distribution of air pollutants was simulated using the ENVI-met microscale model for building configuration and street orientation in the area under investigation. The results demonstrated that street and pathway orientation plays an important role in the accumulation or distribution of pollutants. Accordingly, the density of pollutants is higher in streets that are perpendicular to the prevailing wind direction. Furthermore, the concentration of pollutants in the main streets of the area under study exhibited a significant relationship with their directions. Pollutant concentration was moderate in streets with prevailing north winds, while the highest and lowest amounts of pollutant concentration were observed in streets with south and southwest winds, respectively. It can be concluded that consideration of the climate conditions in urban design and development (wind speed/direction in particular) can be effective in improvement of air quality in urban areas. Air Pollution, Street Orientation, Wind Speed/Direction, Tehran, ENVI-met Model.
Urban Ecology
SEPIDEH MOVAHED; Manouchehr Tabibian
Abstract
Man’s most complex products, cities are confronted with great risks due to both the wide range of risks and changes involved in them and their multiple vulnerabilities. These changes include numerous disorders, some of which are known and predictable, while most are unpredictable and beyond expectation. ...
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Man’s most complex products, cities are confronted with great risks due to both the wide range of risks and changes involved in them and their multiple vulnerabilities. These changes include numerous disorders, some of which are known and predictable, while most are unpredictable and beyond expectation. It therefore seems necessary to address the modern approaches to encountering disorders and disasters. The prevailing perspective has shifted from a mere focus on vulnerability and reinforcement to an increase in resilience against disorder. Therefore, the current research was focused on the idea of resilience as a newly-emerging concept in urbanism issues, and sought to enhance the capability of cities of confronting disorders, particularly environmental crises, as dynamic, self-organizing systems by introducing the notion of resilience to the domain of urbanization through formulation of an integrated model. The significance of the present paper lay in the appreciation of urban resilience thinking as a tool for recognition of the capabilities of urban systems of adapting to changes or absorbing disorders by helping to understand the dynamicity, complexity, processes, and patterns in these systems. Through knowledge of this thinking and the factors affecting its different aspects, the capability of socio-ecological systems such as cities could be increased for adaptation to changes and self-organization. The purpose of this paper was to analyze ecological resilience and determine the factors effective on it based on urban ecology thinking, to identify the criteria, and to generate a model for enhancement of the ecological resilience of cities. It was a qualitative study, where the data were collected from multiple sources using various library methods to be validated through triangulation. Thematic analysis and the thematic network tool were used for data analysis. Through identification of around 45 themes, obtained through examination of more than 50 theoretical and applied studies, and analysis of the relationships between them, the thematic network resulting from their clustering was formulated, consisting of basic, organizing, and comprehensive themes. Based on the qualitative analysis, a series of factors most effective on urban resilience were categorized into six major groups that formed the proposed urban ecological resilience scheme, including natural structure, ecosystem functions and processes, socio-economic functions and processes, urban shape, institutions, and knowledge. Each of the above categories affected urban resilience differently, where the first and the second had direct effects, while the other four influenced it indirectly, by affecting natural elements and biological species as urban assets and affecting ecosystem functions and processes through disorder or reinforcement of ecosystem services. The research results demonstrated that the ecological resilience of cities based on knowledge of urban resilience was affected by dynamic interactions between socio-economic and biophysical processes, where the formulated model and the criteria set as subcategories in the proposed model made it possible to enhance urban resilience. The formulated model serves as a general guide for urban planners, designers, and managers for achievement of ecological resilience in socio-ecological systems such as cities. Furthermore, it covers the gap identified as resulting from absence of an integrated framework in the ecological dimension of urban resilience is covered thanks to the integration of the factors affecting resilience.
Urban Ecology
Hooshmand Alizadeh; Werya Lotfi; Salah Vaisi
Abstract
Man’s unsustainable use of environmental resources needs to be tackled from different perspectives and at multiple levels of land use. Ecological Footprint (EF) is a renewable resource accounting tool that assesses the environmental impacts of urban land uses, and measures the impact of human activities ...
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Man’s unsustainable use of environmental resources needs to be tackled from different perspectives and at multiple levels of land use. Ecological Footprint (EF) is a renewable resource accounting tool that assesses the environmental impacts of urban land uses, and measures the impact of human activities on the environment with respect to the underlying issue of sustainable consumption. EF compares the level of consumption with the available amount of biocapacity to demonstrate how human beings are using natural resources faster than they can regenerate them. It was developed originally as an indicator of the environmental impacts of nations, individuals, or human populations or of organizational and corporate environmental performance and even product sustainability. Given this capability, the environmental impact of the University of Kurdistan campus as a major urban land use in the city of Sanandaj, Iran was evaluated in this study using the component-based footprinting method. Actual data on the five environmental indicators of natural gas, electricity, water, food, and waste were collected during the 2014-2015 academic year. The results indicate that the University of Kurdistan ecological footprint index in the above academic year is -0.56. On that basis, the function and performance of the university has been unsustainable with respect to the examined indicators. In addition, the results indicated that the University of Kurdistan ecological footprint is about 16,675 global hectares, which means that an area of land 165 times larger than the university is needed to compensate for the amount of natural resources consumed and the resulting waste. It can therefore be stated that the University of Kurdistan campus exhibits unsustainable performance in the 2014-2015 academic year. Furthermore, the energy (natural gas and electricity) and water indicators show the highest and lowest levels of environmental impacts with 72.03 and 0.97 percent of total ecological footprint, respectively. Therefore, the environmental impact of energy consumption is about 2.5 times that of the other indicators investigated here (water, food, and waste). As suggested in the literature, the most important indicators used in the ecological footprint model at various universities around the world include energy, fuel consumption in transportation, materials, food, water, waste, and paper consumption, among which energy exhibits the highest level of environmental impacts, as suggested by the results obtained for the University of Kurdistan. On that basis, the University of Kurdistan campus ranks second after the University of Algarve campus (Portuguese) in terms of impact on the environment. Therefore, it is necessary to prioritize energy consumption in the university policies and plans for reduction of natural resource consumption. For that purpose, a comprehensive plan should be developed firstly to monitor the environmental impacts of natural resource useand secondly to modify the consumption pattern and thus reduce the impact of the university on the environmental resources.
Urban Ecology
shler katorani
Abstract
Environmental pollution has attracted greater attention than ever before in the past three decades. On the other hand, noise pollution in cities is a global issue in most countries, considered today as one of the most important environmental problems. Noise pollution level is rising for various reasons ...
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Environmental pollution has attracted greater attention than ever before in the past three decades. On the other hand, noise pollution in cities is a global issue in most countries, considered today as one of the most important environmental problems. Noise pollution level is rising for various reasons such as the increase in population density, the increase in the number of motor vehicles in cities, establishment of industries adjacent to cities, and expansion of construction. The harmful effects of noise pollution on humans do not occur directly in the short run, but the short-term persistence has a significant long-term impact on man. Consequently, the physiological and psychological effects of noise on humans often emerge gradually, affecting the human nervous system in the long run, with negative consequences. In most of the world’s developed and developing countries, the issue of noise pollution has been attended to, and anti-pollution laws have been formulated and enforced. Given the role of noise pollution in the well-being of people in the community, it is of great importance to model and simulate sound transmission, partition noise pollution, and identify areas with excessive noise levels. The purpose of this study was to specify the level of noise pollution in the city of Sanandaj, Iran and its relationship with anxiety level. Therefore, fifty stations with residential, commercial, residential-commercial, and green space land uses were selected, and equivalent sound level was measured using an acoustic device and compared to the standard noise pollution level. In the next step, the obtained data were interpolated using the IDW geostatistical method in the ARCGIS10.4 software due to the lower error rate. The Hamilton questionnaire was then used for investigation of the effect of noise pollution on the citizens’ level of anxiety. The number of distributed questionnaires was 400, of which 351 could be referred to. The results indicated that mean equivalent sound level at all the examined stations was 71,621 dB. On average, the highest noise pollution concerned the commercial sector, followed by the residential-commercial sector, with equivalent sound levels of 73.70 and 71.32 dB, respectively, 60 dB higher than the allowed maximum according to the standard set by Iranian Department of Environment. The results of partitioning demonstrated that the central parts of the city had high levels of pollution. According to the statistical results, there were significant differences in equivalent sound level between all the land uses. The results obtained from the distributed questionnaires showed that there were significant relationships between the demographic variables and level of anxiety. People exposed to noise pollution were the most vulnerable group in terms of increased anxiety level. 54.42% of the respondents reported a high mean level of citizen anxiety, 21.46% reported a moderate level, and 26.82% reported a low level. The results demonstrated that there were significant relationships between the variables. Thus, the higher the noise pollution resulting from congestion, the higher the level of anxiety. The study showed that mean equivalent sound level was higher than the allowed maximum in the area under investigation. Therefore, it was suggested that there should be planning to reduce the noise pollution level and, consequently, the citizens’ level of anxiety along with an enhancement of well-being.
Urban Ecology
Salahaldin Shoshtari; Mahmoud Ghalehnoee; Victoria Ezzatian; Aida Maleki; Mostafa Paknejad; raofeh rahpou
Abstract
The urban heat island phenomenon is one of the challenges with which most metropolises have been struggling due to unplanned city expansions. Multiple factors have led to the emergence and escalation of this phenomenon, which can be classified into three main categories: the macro-climate of the region, ...
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The urban heat island phenomenon is one of the challenges with which most metropolises have been struggling due to unplanned city expansions. Multiple factors have led to the emergence and escalation of this phenomenon, which can be classified into three main categories: the macro-climate of the region, materials used at urban fabric and urban texture. Various suggestions have been given by experts in this area to reduce the severity of this phenomenon and improve the urban microclimate. However, as the phenomenon is different in each city or metropolitan area, various location-specific solutions will be offered to reduce the factors contributing to the phenomenon. The study uses satellite data, including images of the Landsat satellite on July 18, 2015, as well as the overnight satellite images of Modis and the GIS, along with land data from the metropolitan weather stations closest to the selected simulation area where thermal islands were examined. In this regard, the extent of the impact of different uses on the formation and severity of thermal islands in Isfahan was investigated. Based on the findings, applicable suggestions in the field of urban activity are made with an emphasis on the green space. In this paper, on the city level, the main green spaces including green spaces of urban streets and different types of urban parks were examined with regard to their geographical location in terms of the three categories of surface temperature (approximate 24-35°C, 35-40°C, and 40-51°C) and the applied map of each of these categories were developed. Accordingly, at the city level, the temperature in 10% of urban green spaces was above the normal, the temperature in 15% of urban green spaces was in the normal range, and the temperature in 3% of these spaces was lower than the nornal range. The Abbas Abad area was studied in terms of urban usage through a simulation of the effect of green spaces, especially green spaces on the boundaries of the roads on the urban microclimate. This area is one of the areas with the most abundant, old green space in the city. In this regard, an urban green space with old trees was selected in the historical fabric of Isfahan and was modeled using Envi-Met. The simulation results for summer 2015 indicate that, despite the close proximity of the three selected points, about 1°C of difference is seen in the temperature of the three spots. The proximity of the water bodies, and green spaces in particular, is one of the main factors. Additionally, the ground data follows the pattern of simulations points as well. Therefore, different scenarios are proposed for the presence of green spaces and evaluated through simulation. The results of this paper show that small green spaces, if designed based on scientific principles, can have a good effect on the thermal effects of heat islands on the small scale. Also, because of the large scale of urban areas, the combined methods proposed in this study can lead to the application of measures to reduce the negative effects of heat islands for urban management.
Urban Ecology
h d
Volume 6, Issue 23 , August 2017, , Pages 3-16
Abstract
According to Tehran environmental prospect document, Tehran 1404, by 1404 Tehran will be a clean, green city in compliance with latest standards of global cities. Based on this document, in the light of divine elevated instructions, by then, citizens of Tehran will have institutionalized environmental ...
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According to Tehran environmental prospect document, Tehran 1404, by 1404 Tehran will be a clean, green city in compliance with latest standards of global cities. Based on this document, in the light of divine elevated instructions, by then, citizens of Tehran will have institutionalized environmental ethics and demand for preservation of unique natural resources. But, in the literature of sustainable cities, to have a green city as desirable as future Tehran necessitates that urban management organize responsible treatment of nature by providing physical, technological, institutional and legal infrastructure and, accordingly, lead individuals to treat nature ethically based on policies of sustainable urban development. Therefore, ethical treatment of nature is defined as obeying rules and norms that control methods of distributing and possessing natural resources. In such a case, people are regarded as law-abiding and hence respectful of ethics.
Although there is a law for protecting and expanding green space in cities which is guaranteed by all powers (judiciary, executive and legislative) as well as urban management, as the administrator within their duties and authorities, gardens are still being damaged in Tehran. It is theoretically assumed that friendly behavior of citizens with nature can be guaranteed by changing environmental governance through institutional, policy and lawful mechanisms. This study, which is ontologically based on the interpretivist paradigm, conducts deep interviews with key informants using theoretical sampling method to define the process and elements that damage gardens in Tehran within the framework of grounded theory.
The results indicate that ignoring the role of environmental laws in society and lack of credit for the law of preservation and expansion of urban green space as social norms convince individuals that the society recognizes breach of environmental laws and destruction of environment to obtain profit. The crisis of environmental ethics as an internal agent also facilitates destruction of gardens. In other words, it makes people ignore their conscience while destroying gardens and avoid feeling ethical commitment to preserve gardens.
But individuals’ strength of will to destroy gardens in order to gain profit, in spite of the law of preserving and expanding urban green space, is affected by consequences, costs and benefits they expect from destroying gardens. Regarding the lack of decisive judiciary and disciplinary institutions to stop destruction of gardens, individuals dare to destroy gardens by exerting deception, force and influence and disobeying the law of preserving and expanding green space. They expect to gain profit because urban management lacks sufficient competence and prefers urban management over the law of green space. Absence of supervision and sensitivity for executing the law of green space as well as the dependence of urban economy on profit aggravate this issue. Even if judiciary and disciplinary institutions are decisive in punishing disobedience to the law of green space and prohibition of destruction of gardens, the profit gained from destroying gardens will exceed the costs for preserving them; this is because of the confusion in related laws. Therefore, one would have a positive attitude towards profit gain as the main reason for destroying gardens.
In view of the above, it seems that treatment of environment is affected by internal and external factors. Ethical treatment of environment cannot be defined as obeying rules and norms that control methods of distributing and possessing natural resources in society. Ethical treatment of environment is rather a persuasive issue that is not confined to any place and time and is achieved by dignity of ego, but accomplishing it through legal principles and rules will not be feasible and desirable due to its restrictions in comparison with ethics.
Urban Ecology
h m; gh kh
Volume 4, Issue 14 , May 2015, , Pages 31-46
Abstract
Fast and uncontrollable growth of urbanization causes loss of agricultural lands and orchards; it leads to a decrease in green areas and open spaces and causes heavy traffic and environmental pollution. Therefore, an essential step in urban planning, management and evaluation of its effects is to simulate ...
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Fast and uncontrollable growth of urbanization causes loss of agricultural lands and orchards; it leads to a decrease in green areas and open spaces and causes heavy traffic and environmental pollution. Therefore, an essential step in urban planning, management and evaluation of its effects is to simulate the physical development of the city. In order to keep ecosystems functioning well, it is necessary for environmental researchers, managers, and decision makers to understand the spatial dynamics of an ecosystem. Importantly, remotely sensed imagery provides an efficient means of obtaining information on temporal trends and spatial distribution of urban areas needed for understanding, modeling, and projecting land change. The aim of this study is to understand the parameters of physical development at Bonab city with regard to sustainable spatial development of urban issues from ecological and environmental viewpoint in the next two decades. Change detection is an important process for monitoring and managing natural resources and urban development because it provides quantitative analysis of spatial distribution in the area of interest. Detection of changes in land use/ land cover involves use of at least two period data sets. Using Landsat 5 multi temporal satellite images and object oriented techniques, application changes of the lands in 1984-2011 period was evaluated with emphasis on Sprawl expansion of Bonab urban area and its scattered peripheral villages located in the study area. The term Sprawl is used in various ways to mean the gluttonous use of land, uninterrupted monotonous development, leapfrog discontinuous development and inefficient use of land. Urban sprawls are characterized by premature or poorly planned conversion of rural land to other uses, the creation of areas of urban development or uses which are not functionally related to adjacent land uses, the creation of areas of urban development or uses which fail to maximize the use of existing public facilities and the use of areas within which public services are provided. For calculating this parameter Holdern index was used. Results show that 41 percent of urban growth of Bonab city has risen from sprawl growth. Based on the results, urban area of Bonab and its six peripheral villages which was 608.4 hectares in 1984 reached 1716.8 ha in 2011. 1065.51 hectares of the aforementioned lands was developed on garden and agricultural lands which demand management of future development based on the principles of sustainable development. Therefore, effective factors of physical development in the urban area of Bonab city was classified under 14 layers and by using the logistic regression method, the possibility of urban development map was prepared. After predicting the future pattern of urban development in Bonab city, the protection of gardens and green spaces strategy in the urban development process was implemented using the hexagonal layout of possibility for urban development map, giving the necessary space for development, and extraction of a natural green belt with an area of 21.83 km. Furthermore, a ban in urban development in the surroundings of the proposed green belt was applied, maintaining the ecological reserves of Bonab city by reducing agricultural and garden lands, decreasing degradation and controlling sprawl expansion and separation of towns and villages.
Urban Ecology
h d; m r; a z
Volume 3, Issue 9 , February 2014, , Pages 31-44
Abstract
Land use planning and determination of developmental priorities based on regional conditions and characteristics are considered as one of the major aspects of planning on a regional scale. One approach in this field is the determination of land use types. The common point in all applied methods of ecological ...
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Land use planning and determination of developmental priorities based on regional conditions and characteristics are considered as one of the major aspects of planning on a regional scale. One approach in this field is the determination of land use types. The common point in all applied methods of ecological potential assessment is to consider development as the assessment goal in the research process. This occurs when in the allocation of types of uses under equal condition, different types of development can be studied and the most appropriate one selected according to conditions. Therefore, this study tries to apply a model which enables the assessment of land use with different types of development. Since taking into account all types of development simultaneously causes prioritization conflicts (one or more types of development might have the same priority level at one point when different developmental priorities overlap), the major challenge would be to resolve the inter-developmental conflicts. Therefore, the proposed model must be able to resolve such spatial conflict. This study, based on conducted research on assessment of ecological potential and using multi-objective assessment methods, evaluates the ecological potential of Noushahr County in four types of urban, agricultural, industrial, and natural development using a new concept known as “verbal logic”. It tends to offer an integral model for simultaneous analysis of different types of development. On this basis, the method employed in this study has two main sections: the first section deals with ecological assessment based on multi- objective assessment model. In this section, a model of appropriate locations for all the four developments is distinctively identified which results in the recommendation of location priorities for each type of land use development. In the second section, the verbal logic is used to present the integral prioritization areas which cover all the priorities simultaneously. The logic combines the priorities of all types of development employing quantitative approaches and ultimately resolves the conflicts arising from overlapping of priorities of different development types using the conditional rules obtained from the major goal of assessment. On this basis, this model offers priority zoning of integral land capacity in regards to developmental priorities; the major goal of assessment is" zoning the land for optimum allocation of agricultural, urban, and industrial development while protecting environmental values". The model results demonstrate that in integral assessment of a variety of development, only 1% of the region is not suffering inter-developmental conflict while a large part of the region is suffering conflict between assessment priorities of two or more types of development. Only 1 % of all conflict types in the region is dedicated to top priority conflicts in all development types. Nearly 73% of conflicts are devoted to the conflict amongst the three lower priorities. Taking into consideration that the decision-making process of the model is based on the major goal of assessment, the model allocates the desired land to natural development and prevents the expansion of other developments in these areas to resolve the conflict among all priorities. Meanwhile, the study of spatial distribution of various developments in the city and its comparison with land use show that much of the central and southern parts are dedicated to natural development as a first priority while the industrial, urban and agricultural developments are largely linked to each other and are located in the central and northern parts of the city mostly near lowlands at low altitudes.
Urban Ecology
ش ش; ش ش; ش ش
Volume 2, Issue 8 , December 2013, , Pages 13-30
Urban Ecology
Volume 2, Issue 5 , March 2013, , Pages 61-72
Abstract
Over the past two decades, several models have been used to calculate environmental vul-nerability with Approach collective decisions to mitigate the effects of the natural hazards. Location of cities and villages, and site selection of residential units, services, and indus-tries and recreation should ...
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Over the past two decades, several models have been used to calculate environmental vul-nerability with Approach collective decisions to mitigate the effects of the natural hazards. Location of cities and villages, and site selection of residential units, services, and indus-tries and recreation should be harmonized with expansion of geology, geomorphology, soil and climatology sciences. Therefore, without understanding their natural features, the construction of urban and rural areas and related activities associated with their spatial substrate is not reasonable. Yasuj urban area is located in narrow plains in the western foothills of the Zagros Mountains. The area of this place is about 12776 hectares and its average topographic height is about 1850 mASL. The area consists of 42 villages whose population is over 150 thousand and its city center is Yasouj. The main purpose of this study is to put stress on the theory of sustainable development in Yasuj urban areas. The study of natural vulnerability of Yasuj urban areas was performed with an emphasis on the natural and environmental structure. Methods used to analyze the vulnerability include Fuzzy logic, Analytic Hierarchy Process (AHP) and environmental indicators that were used by Geographic Information System (GIS). Based on the criteria and sub criteria of the study, the study area affected by natural features and special characteristics are threatened with some environmental restrictions and natural hazards. Due to young and active faults, the urban area shows great potential for earthquake. The probability of flood in the area increases as a result of the features of the mountain, sharp slopes, existence of several torrent rivers, relatively high amounts of rainfall, especially during the cold season. Structure and texture of alluvial plains and foothills are almost weak. In addition, the steep foothills can increase probability of hillside movements and phenomena such as the downfall of soil and rock, landslides and avalanche at snowy periods. According to the results obtained from combining various layers of environmental data layers car -ried out on the basis of analytic hierarchy process (AHP) model, it became clear that ,in Yasuj urban area, central parts of the plain have the lowest environmental vulnerability with the rise of the risk level towards the mountainous area. The study not only reveals that proximity to faults has the highest fuzzy membership degree, but also suggests that collaboration with other environmental hazards such flood risk (distance from the river), slope and land use, shows the highest vulnerability. The surrounding mountainous areas (Zagros) in Yasuj urban area which are tectonically active parts of the area have higher risk in comparison with those in the plain. Considering the results, growth and develop -ment of the city toward the mountains will encounter high vulnerability. These results corresponded with the capability of the forest parts of the mountainous areas. Therefore, the development of the city construction toward the mountain would cause sever damage to mountain ecosystems, plant and animal life. Thus, areas characterized by high vulner -ability should be protected since they have not only high potential for being risky but also are vulnerable to the development of human activities (regions of oak forests and rivers protection area). The results of this research lead the policy of regional development to decrease the possibility of environmental vulnerability. The assessment and combination of the results of the information layers studies signal the high environmental vulnerabilityin peripheral parts of urban area due to the overlapping of different natural hazards that tend toward the center of the plain. Finally, the salient point of studying the area shows that in the absence of any planning and measurement of the ecological capability of the land, development inflicts serious environmental damage, which , in turn, may harm hu -man societies in the future.
Urban Ecology
Volume 1, Issue 3 , August 2012, , Pages 24-33
Abstract
Tehran has various environmental problems, which environmental pollution is one of the most important ones. There are numerous organizations responsible for the urban environment management and lack of coordinating and the discord among them is of the reasons for the emergence of the environmental problems ...
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Tehran has various environmental problems, which environmental pollution is one of the most important ones. There are numerous organizations responsible for the urban environment management and lack of coordinating and the discord among them is of the reasons for the emergence of the environmental problems of Tehran. In the present research, besides investigating the feasibility of giving urban environmental management to the municipality, It is tried some methods be presented for the integrated and unity of the urban environmental management. On this base with the use of grounded theory methodology, through the study of documents and interviews with authorities and experts in this affair, the Tehran environmental management issue has been discussed in the pattern of five management duties, including planning, organizing, leadership, control, and supplying of resources and the conditions, strategies, and resultant consequences of revealed phenomenon were presented in the pattern of a paradigmatic model. In this methodology, sampling was done in subjective and snowball manner, and coding method was used for analyzing results obtained. Our results showed that there is no possibility for comprehensive and complete assigning environment management to municipality. However, on the other hand, the abovementioned management duties can be assigned to municipality in a relative manner, and environmental management can be done in integrated cooperation with other related organizations. Moreover, it requires some capacities be made in three structural, lawful, and cultural scopes in municipality organization in order to make municipality able in doing assigned duties.
Urban Ecology
Volume 1, Issue 2 , June 2012, , Pages 57-70
Abstract
Suitable land locating is one of the most important factors of housing production, since the multifaceted nature of this process is very complex. Using models and software in land locating facilitates decision making and helps in optimum site selection. Analytical Hierarchy Process (AHP) is one of the ...
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Suitable land locating is one of the most important factors of housing production, since the multifaceted nature of this process is very complex. Using models and software in land locating facilitates decision making and helps in optimum site selection. Analytical Hierarchy Process (AHP) is one of the main decision-making methods that works with giving weight to criteria. Using this method criteria and sub-criteria will be classified and finally the best alternative for locating will be selected. In this paper with the goal of facilitating the best land locating for residential space, using descriptive-analytical method, first we explain the process of the method, then the effective criteria in residential land locating will be introduced and the hierarchy tree of criteria will be drawn. The criteria has been set in questionnaire format and distributed between urban studies and housing Experts. The average weight of every criteria and sub-criteria in the way of binary comparisons has been calculated using Excel software. After Prioritization of criteria in AHP method, Realization of criteria Surveyed in 13 Masken-e-Mehr projects as a case study. The necessary information for locating in the questionnaire format has been extracted from Yazd urban organization and then data has been classified and analyzed and finally analytical matrix for locating residential project of Yazd has been drawn.
