تحلیل فضایی مخاطرات محیطی

تحلیل فضایی مخاطرات محیطی

نگرشی جدید بر زیست پذیری شهری تهران: آسایش حرارتی شرط اولیه برای ارتقاء کیفیت. نمونه موردی منطقه 22

نویسندگان
1 دانشگاه تهران، گروه جغرافیا و برنامه ریزی شهری
2 انشگاه تهران، گروه جغرافیا و برنامه ریزی شهری
چکیده
زیست پذیری شهری بیان کننده چگونگی عملکرد سیستم شهر است، هماهنگی بین زیر سیستم های شهر باعث ارتقاء کیفیت زیست پذیری می شود. کالبد و ساختار فیزیکی شهر بایستی با محیط زیست طبیعی هماهنگ باشد تا جامعه اجتماعی در آن به رفاه اقتصادی و اجتماعی برسند که در نهایت منجر به رضایت و شادی شهروندان می شود. احساس رضایت و رفاه اجتماعی شهروندان در یک شهر طبیعی سالم و پاک اتفاق می افتد. همانطور که زندگی در شوره زار و یا اقلیم بسیار گرم رضایت ساکنین را ایجاد نمی کند، بی توجهی به محیط زیست طبیعی نمی تواند باعث ارتقاء کیفیت زندگی و رفاه شهروندان شود. این تحقیق سعی دارد بر اهمیت شرایط محیط زیست در شهر زیست پذیر بپردازد. در بین مؤلفه های محیط زیست، اقلیم و شرایط آب و هوایی مهمترین و بیشترین نقش را بر ارتقاء کیفیت زیست پذیری ایفا می کنند. بررسی کیفیت زیست پذیری شهری توسط سه رویکرد کالبدی، محیط زیست و ادراکی- اجتماعی صورت گرفته است. در رویکرد کالبدی دو شاخص بسیار مهم ضریب دید آسمان (SVF) و نسبت محصوریت یا ارتفاع به عرض خیابان (H/W) و در رویکرد محیط زیستی شاخص آسایش محیطی دمای معادل فیزیولوژیک (PET) در روزهای 16، 17 و 18 مرداد سال 1397 اندازه گیری و محاسبه شدند. همچنین ارزیابی ادراکی و ذهنی شرایط محیط طبیعی از طریق پرسشنامه های کیفی توسط استفاده کننده گان از دو نوع فضای عمومی ( پارک شهدای خلیج فارس و خیابان های شهری ) صورت گرفت. نتایج نشان دادند که میانگین آسایش حرارتی در فضاهای باز عمومی در سطح شرایط استرس زای شدید قرار دارد. در صورتیکه در خیابان های با ضریب دید آسمان کم و نسبت محصوریت بالا ، کمینه مقدار آسایش حرارتی دیده شد. ارتباط خطی مثبت بین دمای معادل فیزیولوژیکی و احساس حرارتی استفاده کننده گان از فضا بدست آمد. رضایت از مطلوبیت آسایش حرارتی از سوی پرسش شوندگان چه در روز و چه در شب کمترین رای را به خود اختصاص داد. که در فصل تابستان با توجه به زمان اوج استفاده از فضاهای تفریحی نتیجه بسیار خوبی نمی باشد. این تحقیق نشان داد که ملاحظات محیطی در راستای ارتقاء کیفیت زیست پذیری و در نهایت توسعه پایدار در طراحی فضاهای شهری از سوی طراحان ، برنامه ریزان شهری و سازندگان در منطقه تازه ساخت 22 صورت نگرفته است . دانش استفاده از اقلیم و شاخص های آن ضروری است در مطالعات طرح جامع و تفصیلی شهری لحاظ شود.
کلیدواژه‌ها

عنوان مقاله English

A new Approach of Urban livability in Tehran: Thermal Comfort as a Primitive Condition to Enhance the Quality. Case study, District 22

نویسندگان English

ahmad porahmad 1
Hossein Hataminezhad 1
Keramatollah Ziyari 2
seaideh alijani 1
1 University of Tehran
2 University of Tehran
چکیده English

A new Approach to Urban livability, Thermal Comfort as the Primitive Condition to enhance the livability: Case study, District 22 of Tehran.





Ahmad Porahmad: Professor of Urban Geography and Planning, University of Tehran

Hossain Hataminezhad: Professor of Urban Geography and Planning, University of Tehran

keramatollah Ziyari: Professor of Urban Geography and Planning, University of Tehran

Saeideh Alijani*: PhD candidate of Urban Geography and Planning, University of Tehran



The concept of urban livability is defined as the quality of life and wellbeing of urban residents. That is the interaction of people, environment and built environment. The residents can achieve happy life and well-being only when the nature surrounding them is happy and healthy. According to the range of welfare concept there is a spectrum of quantitative indicators that directly measure (human body temperature, heart rate, air temperature, wind speed ...) and qualitative indicators such as quality of life, pleasure and joy. The comfort and ease of environment are in the middle of the spectrum, in other words, the intrinsic concept of ambient comfort is environment. The inadequacy of natural environment will affect both indicators in the spectrum and lead to citizens' dissatisfaction and decline in social welfare and threaten the health of humans. Living in a salty marsh or very dry hot climate is never happy and satisfied. Accordingly, many concepts such as living quality, living environment, and quality of place, quality of life and sustainability are often used interchangeably with livability).

This research is trying to weight the natural environment at least equal to the other two components of the sustainable development triangle. Among the components of natural environment, climate is playing the most important and significant role. Urban climate affects all aspects of city including building interiors, city architecture and open spaces. Thermal comfort of open spaces promote the social life and interrelations of residents. Therefore, in order to promote the social relations and economic activities especial consideration should be paid to open spaces. Accordingly, two types of data were measured for calculating the thermal comfort in the district 22. Subjective and objective evaluations which present qualitative and quantitative data. Objective data includes micrometeorological measurements with mobile instruments. Subjective data evaluated actual sensation vote or perception vote of thermal comfort by people using the urban open spaces. To this goal, questionnaires were prepared and scattered through space users simultaneously with micrometeorological measurements. Subjective data evaluated perceptual sensation vote of thermal comfort by people using the urban open spaces in three hot days of August 2018. Nine points are selected for site measuring and field survey which are representative of two types of urban open spaces in this research:1) Urban park and 2) street. Four cardinal points were chosen adjacent to the Shohadaye Khalije Fars Lake inside the park located in sidewalk pathway around the Lake. Other five points were selected in streets with different orientation and aspect ratio through the district. The physiologically equivalent temperature (PET), mean radiant temperature (Tmrt), sky view factor (SVF) and aspect ratio (H/W) are the most important indicators in this research which were calculated for evaluating comfort in the district.

Results showed that urban open spaces in the district are discomfort and expose people to the extreme heat stress; over 40°C. This determines that, the natural environment especially around the Shohadaye Khalije Fars is not comfort. The questionnaire also indicated that people felt warm and dissatisfied.

There is a high linear correlation between thermal comfort and mean radiant temperature and globe temperature. Therefore, it is concluded that thermal comfort in the district, is directly affected by urban areas. Also in the streets with low SVF and high aspect ratio, PET were calculated more comfortable than other streets. Point 5 at Naghibzade street, confirmed the effect of urban geometry on thermal comfort. Otherwise, the lack of tremendous trees for creating shade is visible especially around the lake. The high linear correlation between Tmrt and SVF around the lake confirmed the openness of the area and the high amount of solar radiation. Therefore, planting more trees for creating the shade effect is necessary.

The perceptual analysis of thermal comfort indicated that by increasing of PET, people felt warmer. However, in a city like Tehran, people are more resistance to the heat stress. In addition, the characteristics of human body strongly depends on psychology and individual features and is a hard issue to predict. Otherwise, the people who felt warm were more than those felt slightly warm which indicates dissatisfaction of people. To be noticed that, thermal comfort of above 40 °C in summer is an alarm to urban planner and designers to rethink about climate consideration and global warming as a most important urban challenge in the district seriously. Besides, the consideration of thermal comfort and urban geometry should be imbedded into the comprehensive plan. This research proved that the climatic consideration for improving the quality of life and livability is important and urban designers and planners should rethink and review the comprehensive plan of Tehran to make a livable and sustainable city in the future.

Keywords: urban livability, climate comfort, sustainable development, urban sustainability, urban geometry, physiologically equivalent temperature, district 22 of Tehran.














کلیدواژه‌ها English

urban livability
thermal comfort
physiologically equivalent temperature (PET)
mean radiant temperature (Tmrt)
urban geometry
District 22
Abreu-Harbich, L. V., Labaki, L. C., & Matzarakis, A. (2014). Thermal bioclimate in idealized urban street canyons in Campinas, Brazil. Theoretical and applied climatology, 115(1-2), 333-340.
Abreu-Harbich, L. V., Labaki, L. C., & Matzarakis, A. (2014). Thermal bioclimate as a factor in urban and architectural planning in tropical climates—the case of Campinas, Brazil. Urban Ecosystems, 17(2), 489-500.
Alijani, B., Ghohroudi, M., & Arabi, N. (2008). Developing a climate model for Iran using GIS. Theoretical and Applied Climatology, 92(1-2), 103-112.
Alijani, S., & Alijani, B. (2011). Analysis of climate hazards in relation to urban designing in Iran. Advances in Science and Research, 6(1), 173-178.
Beatley, T. (2011). Biophilic cities: integrating nature into urban design and planning. Island Press.
Beatley, T., & Newman, P. (2013). Biophilic cities are sustainable, resilient cities. Sustainability, 5(8), 3328-3345.
Bourbia, F., & Awbi, H. B. (2004). Building cluster and shading in an urban canyon for hot dry climate: Part 1: Air and surface temperature measurements. Renewable energy, 29(2), 249-262.
Bourbia, F., & Awbi, H. B. (2004). Building cluster and shading in an urban canyon for hot dry climate: Part 2: Shading simulations. Renewable Energy, 29(2), 291-301.
Bourbia, F., & Boucheriba, F. (2010). Impact of street design on urban microclimate for semi-arid climate (Constantine). Renewable Energy, 35(2), 343-347.
Brajer, V., Hall, J., & Rahmatian, M. (2012). Air pollution, its mortality risk, and economic impacts in Tehran, Iran. Iranian journal of public health, 41(5), 31.
Brundtland, G. H., Khalid, M., Agnelli, S., & Al-Athel, S. (1987). Our common future. New York.
Chatzidimitriou, A., & Yannas, S. (2017). Street canyon design and improvement potential for urban open spaces; the influence of canyon aspect ratio and orientation on microclimate and outdoor comfort. Sustainable cities and society, 33, 85-101.
Correa, E., Ruiz, M. A., Canton, A., & Lesino, G. (2012). Thermal comfort in forested urban canyons of low building density. An assessment for the city of Mendoza, Argentina. Building and environment, 58, 219-230.
Chen, L., & Ng, E. (2012). Outdoor thermal comfort and outdoor activities: A review of research in the past decade. Cities, 29(2), 118-125.
Chen, L., & Ng, E. (2011). Quantitative urban climate mapping based on a geographical database: a simulation approach using Hong Kong as a case study. International Journal of Applied Earth Observation and Geoinformation, 13(4), 586-594.
Cheng, V., Ng, E., Chan, C., & Givoni, B. (2012). Outdoor thermal comfort study in a sub-tropical climate: a longitudinal study based in Hong Kong. International journal of biometeorology, 56(1), 43-56.
Chen, L., Yu, B., Yang, F., & Mayer, H. (2016). Intra-urban differences of mean radiant temperature in different urban settings in Shanghai and implications for heat stress under heat waves: a GIS-based approach. Energy and Buildings, 130, 829-842.
Đukić, A., & Vukmirović, M. (2011). Walking as a climate-friendly transportation mode in an urban environment case study: Belgrade.
Djukic, A., Vukmirovic, M., & Stankovic, S. (2016). Principles of climate-sensitive urban design analysis in the identification of suitable urban design proposals. Case study: Central zone of Leskovac competition. Energy and Buildings, 115, 23-35.
Ghanghermeh, A., Roshan, G., Orosa, J., Calvo-Rolle, J., & Costa, Á. (2013). New climatic indicators for improving urban sprawl: a case study of Tehran city. Entropy, 15(3), 999-1013.
Gough, I. (2015). Climate change and sustainable welfare: the centrality of human needs. Cambridge Journal of Economics, 39(5), 1191-1214.
Habitat, U. N. (2016). Urbanization and development: emerging futures. World cities report, 3(4), 4-51.
Heidari, S., & Azizi, M. (2017). Evaluation of thermal comfort in urban areas. International Journal of Urban Management and Energy Sustainability, 1(1), 49-58.
Holst, J., & Mayer, H. (2011). Impacts of street design parameters on human-biometeorological variables. Meteorologische Zeitschrift, 20(5), 541-552.
Höppe, P. (1999). The physiological equivalent temperature–a universal index for the biometeorological assessment of the thermal environment. International Journal of Biometeorology, 43(2), 71-75.
Jamei, E., & Rajagopalan, P. (2016). Urban planning and pedestrian thermal comfort-A study of growing Melbourne city. In 4th IC2UHI (pp. 1-10). The National University of Singapore.
Jamei, E., & Rajagopalan, P. (2017). Urban development and pedestrian thermal comfort in Melbourne. Solar Energy, 144, 681-698.
Jamei, Y., Rajagopalan, P., & Sun, Q. C. (2019). Spatial structure of surface urban heat island and its relationship with vegetation and built-up areas in Melbourne, Australia. Science of The Total Environment, 659, 1335-1351.
Jänicke, B., Meier, F., Hoelscher, M. T., & Scherer, D. (2015). Evaluating the effects of façade greening on human bioclimate in a complex urban environment. Advances in Meteorology, 2015.
Johansson, E., & Emmanuel, R. (2006). The influence of urban design on outdoor thermal comfort in the hot, humid city of Colombo, Sri Lanka. International journal of biometeorology, 51(2), 119-133.
Kántor, N., Chen, L., & Gál, C. V. (2018). Human-biometeorological significance of shading in urban public spaces—Summertime measurements in Pécs, Hungary. Landscape and urban planning, 170, 241-255.
Katzschner, L. (2004). Open space design strategies based on thermal comfort analysis. In Proc. PLEA (Vol. 1, pp. 47-52).
Kellert, S. (2005). Building for life. Designing and Understanding the Human–Nature Connection.
Klemm, W., Heusinkveld, B. G., Lenzholzer, S., & van Hove, B. (2015). Street greenery and its physical and psychological impact on thermal comfort. Landscape and Urban Planning, 138, 87-98.
Krüger, E. L., Minella, F. O., & Rasia, F. (2011). Impact of urban geometry on outdoor thermal comfort and air quality from field measurements in Curitiba, Brazil. Building and Environment, 46(3), 621-634.
Lau, K. K. L., Lindberg, F., Rayner, D., & Thorsson, S. (2015). The effect of urban geometry on mean radiant temperature under future climate change: a study of three European cities. International journal of biometeorology, 59(7), 799-814.Ley, D. (1990). Urban liveability in context. Urban Geography, 11(1), 31-35.
Lee, H., & Mayer, H. (2016). Validation of the mean radiant temperature simulated by the Rayman software in urban environments. International journal of biometeorology, 60(11), 1775-1785.
Lindberg, F., & Grimmond, C. S. B. (2010). Continuous sky view factor maps from high resolution urban digital elevation models. Climate Research, 42(3), 177-183.
Lin, T. P. (2009). Thermal perception, adaptation, and attendance in a public square in hot and humid regions. Building and environment, 44(10), 2017-2026.
Lindberg, F., & Grimmond, C. S. B. (2011). Nature of vegetation and building morphology characteristics across a city: influence on shadow patterns and mean radiant temperatures in London. Urban Ecosystems, 14(4), 617-634.
Mayer, H., & Höppe, P. (1987). Thermal comfort of man in different urban environments. Theoretical and applied climatology, 38(1), 43-49.
Matzarakis, A., Mayer, H., & Iziomon, M. G. (1999). Applications of a universal thermal index: physiological equivalent temperature. International journal of biometeorology, 43(2), 76-84.
Matzarakis, A., Rutz, F., & Mayer, H. (2007). Modeling radiation fluxes in simple and complex environments—application of the Rayman model. International journal of biometeorology, 51(4), 323-334.
Matzarakis, A., & Mayer, H. (1996). Another kind of environmental stress: thermal stress. WHO newsletter, 18(January 1996), 7-10.
Manchanda, S., & Steemers, K. (2012). Environmental Control and the Creation of Well-being. In Sustainable Environmental Design in Architecture (pp. 69-81). Springer, New York, NY.
Mirmoghtadaee, M. (2012). The relationship between land use, socio-economic characteristics of inhabitants and travel demand in new towns–a case study of Hashtgerd New Town (Iran). International Journal of Urban Sustainable Development, 4(1), 39-62.
Morakinyo, T. E., Kong, L., Lau, K. K. L., Yuan, C., & Ng, E. (2017). A study on the impact of shadow-cast and tree species on in-canyon and neighborhood's thermal comfort. Building and Environment, 115, 1-17.
Mayer, H., Holst, J., Dostal, P., Imbery, F., & Schindler, D. (2008). Human thermal comfort in summer within an urban street canyon in Central Europe. Meteorologische Zeitschrift, 17(3), 241-250.
Nikolopoulou, M., & Steemers, K. (2003). Thermal comfort and psychological adaptation as a guide for designing urban spaces. Energy and buildings, 35(1), 95-101.
Oke, T. R., Johnson, G. T., Steyn, D. G., & Watson, I. D. (1991). Simulation of surface urban heat islands under ‘ideal conditions at night Part 2: Diagnosis of causation. Boundary-Layer Meteorology, 56(4), 339-358.
Oke, T. R. (1988). Street design and urban canopy layer climate. Energy and buildings, 11(1-3), 103-113.
Oke, T. R. (1982). The energetic basis of the urban heat island. Quarterly Journal of the Royal Meteorological Society, 108(455), 1-24.
Oke, T. R., & Cleugh, H. A. (1987). Urban heat storage derived as energy balance residuals. Boundary-Layer Meteorology, 39(3), 233-245.
Offerle, B., Grimmond, C. S. B., Fortuniak, K., & Pawlak, W. (2006). Intraurban differences of surface energy fluxes in a central European city. Journal of Applied Meteorology and Climatology, 45(1), 125-136.
Rafieian, M., & Sheikhi, S. (2015). Integrating climate change adaptation and mitigation with urban planning for a livable city in Tehran. Space Ontology International Journal, 4(2), 9-22.
Ratti, C., Di Sabatino, S., & Britter, R. (2006). Urban texture analysis with image processing techniques: winds and dispersion. Theoretical and Applied Climatology, 84(1-3), 77-90.
Roshan, G., Yousefi, R., & Fitchett, J. M. (2016). Long-term trends in tourism climate index scores for 40 stations across Iran: the role of climate change and influence on tourism sustainability. International journal of biometeorology, 60(1), 33-52.
Roshan, G., & Nastos, P. T. (2018). Assessment of extreme heat stress probabilities in Iran's urban settlements, using the first-order Markov chain model. Sustainable cities and society, 36, 302-310.
Roshan, G., Yousefi, R., & Fitchett, J. M. (2016). Long-term trends in tourism climate index scores for 40 stations across Iran: the role of climate change and influence on tourism sustainability. International journal of biometeorology, 60(1), 33-52.
Ruth, M., & Franklin, R. S. (2014). Livability for all? Conceptual limits and practical implications. Applied Geography, 49, 18-23.
Shashua‐Bar, L., Tzamir, Y., & Hoffman, M. E. (2004). Thermal effects of building geometry and spacing on the urban canopy layer microclimate in a hot‐humid climate in summer. International Journal of Climatology, 24(13), 1729-1742.
Shashua-Bar, L., & Hoffman, M. E. (2004). Quantitative evaluation of passive cooling of the UCL microclimate in hot regions in summer, case study: urban streets and courtyards with trees. Building and Environment, 39(9), 1087-1099.
Shishegar, N. (2013). Street Design and Urban Microclimate: Analyzing the Effects of Street Geometry and Orientation on Airflow and Solar Access in Urban Canyons. Journal of Clean Energy Technologies, 1(1).
Souza, L. C. L. (2007). Thermal environment as a parameter for urban planning. Energy for Sustainable Development, 11(4), 44-53.
Streiling, S., & Matzarakis, A. (2003). Influence of single and small clusters of trees on the bioclimate of a city: a case study. Journal of Arboriculture, 29(6), 309-316.
Standard, A. S. H. R. A. E. (2013). Standard 55-2013. Thermal environmental conditions for human occupancy.
Sun, S., Xu, X., Lao, Z., Liu, W., Li, Z., García, E. H., ... & Zhu, J. (2017). Evaluating the impact of urban green space and landscape design parameters on thermal comfort in the hot summer by numerical simulation. Building and Environment, 123, 277-288.
Svensson, M. K. (2004). Sky view factor analysis–implications for urban air temperature differences. Meteorological Applications, 11(3), 201-211.
Tan, Z., Lau, K. K. L., & Ng, E. (2016). Urban tree design approaches for mitigating daytime urban heat island effects in a high-density urban environment. Energy and Buildings, 114, 265-274.
Thorsson, S., Lindberg, F., Eliasson, I., & Holmer, B. (2007). Different methods for estimating the mean radiant temperature in an outdoor urban setting. International journal of climatology, 27(14), 1983-1993.
Thorsson, S., Lindqvist, M., & Lindqvist, S. (2004). Thermal bioclimatic conditions and patterns of behavior in an urban park in Göteborg, Sweden. International Journal of Biometeorology, 48(3), 149-156.
Toudert, F. A., Djenane, M., Bensalem, R., & Mayer, H. (2005). Outdoor thermal comfort in the old desert city of Beni-Isguen, Algeria. Climate Research, 28(3), 243-256.
Toudert, F. A. (2005). Dependence of outdoor thermal comfort on street design in the hot and dry climate. Meteorologisches Instituts der Albert-Ludwigs-Universität.
Toudert, F. A., & Mayer, H. (2006). Numerical study on the effects of aspect ratio and orientation of an urban street canyon on outdoor thermal comfort in the hot and dry climate. Building and environment, 41(2), 94-108.
Toudert, F. A., & Mayer, H. (2007). Effects of asymmetry, galleries, overhanging facades and vegetation on thermal comfort in urban street canyons. Solar energy, 81(6), 742-754.
Unger, J. (2004). Intra-urban relationship between surface geometry and urban heat island: review and a new approach. Climate Research, 27(3), 253-264.
Van Dorst, M. (2012). Liveability. In Sustainable Urban Environments (pp. 223-241). Springer, Dordrecht.
Van Kamp, I., Leidelmeijer, K., Marsman, G., & De Hollander, A. (2003). Urban environmental quality and human well-being: Towards a conceptual framework and demarcation of concepts; a literature study. Landscape and urban planning, 65(1-2), 5-18.
Vanos, J. K., Warland, J. S., Gillespie, T. J., & Kenny, N. A. (2010). Review of the physiology of human thermal comfort while exercising in urban landscapes and implications for bioclimatic design. International journal of biometeorology, 54(4), 319-334.
Vernon, H. M. (1932). The measurement of radiant heat in relation to human comfort. Journal of Industrial Hygiene, 14, 95-111.
Yang, F., Lau, S. S., & Qian, F. (2011). Thermal comfort effects of urban design strategies in high-rise urban environments in a sub-tropical climate. Architectural Science Review, 54(4), 285-304.
Yang, F., Lau, S. S., & Qian, F. (2010). Summertime heat island intensities in three high-rise housing quarters in inner-city Shanghai China: Building layout, density, and greenery. Building and Environment, 45(1), 115-134.
Yang, F., & Chen, L. (2016). Developing a thermal atlas for climate-responsive urban design based on empirical modeling and urban morphological analysis. Energy and buildings, 111, 120-130.
Wang, X. (2010). The research on the evaluation index system of livable rural areas in China—by the case of rural areas in Henan Province. Agriculture and Agricultural Science Procedia, 1, 456-461.
Wilson, F. D. (1984). Urban ecology: Urbanization and systems of cities. Annual Review of Sociology, 10(1), 283-307.
World Health Organization. (2018). Global action plan on physical activity 2018–2030: more active people for a healthier world. World Health Organization.
Xue, F., Gou, Z., & Lau, S. S. Y. (2017). Green open space in high-dense Asian cities: Site configurations, microclimates and users’ perceptions. Sustainable cities and society, 34, 114-125.
Xue, F., Gou, Z., & Lau, S. S. Y. (2017). Green open space in high-dense Asian cities: Site configurations, microclimates and users’ perceptions. Sustainable cities and society, 34, 114-125.