بررسی تأثیرات افزایش ارتفاع بر کیفیت هوای بلوک شهری، نمونه موردی: بلوک مسکونی شهری در مرکز شهر اصفهان
محورهای موضوعی : فصلنامه علمی و پژوهشی پژوهش و برنامه ریزی شهریملیحه سادات سیدالعسکری 1 , امیر حسین پیمان راد 2 , فرهاد رجائی 3
1 - کارشناس معماری دفتر تسهیلگری و نوسازی
2 - کارشناس نظارت دفتر تهسیلگری و نوسازی بافت فرسوده شیراز
3 - استاد حق التدریس دانشگاه آزاد اسلامی واحد ارومیه
کلید واژه: دما, لوک شهری, ارتفاع ساختمان‌ها, سرعت باد, ضریب جابه جایی عمودی, Envi-met,
چکیده مقاله :
با افزایش جمعیت شهرنشینی، شهرها به سمت بلند مرتبه سازی و متراکم شدن در حرکت هستند. شهر اصفهان به دلیل مهاجرپذیری و افزایش جمعیت در سال‌های اخیر شاهد افزایش بی رویه ساخت و ساز و بلند مرتبه سازی هست.این در حالی است که این شهر به دلیل وجود چندین کارخانه و پالایشگاه در نزدیک شهر و ترافیک بالا به یکی از شهرهای آلوده در ایران تبدیل شده است. بر طبق آمار مرکز هواشناسی اصفهان در سال 92، 67 روز هوای شهر ناسالم بوده است.که این روزهای آلوده بیشتر در طول زمستان به دلیل پدیده وارونگی هوا است.در این پژوهش اثرات بلند مرتبه سازی و تغییرات ارتفاع ساختمان‌ها را در یک بلوک شهری، در مرکز شهر اصفهان، در 15 سال قبل،شرایط موجود و 15 سال آینده با نرم افزار ENVI-met مورد سنجش قرار گرفته است. در طول زمستان تأثیرات افزایش ارتفاع ساختمان‌ها بر دمای بلوک شهری، سرعت باد در حالت افقی (سطح عابر پیاده) و ضریب جابه جایی عمودی بررسی شده است. نتایج نشان می‌دهد که در زمستان با افزایش ارتفاع، دمای بلوک شهری تا میزان 0.025 درجه کاهش می‌یابد. سرعت باد افقی (در سطح عابر پیاده) تا 0.2 M/S افزایش می‌یابد، که این ناخوشایند است. از سوی دیگر ضریب جا‌به‌جایی عمودی در زمستان با افزایش ارتفاع کاهش می‌یابد. این تغییرات در دما، سرعت باد در نزدیک سطح زمین و ضریب جابه جایی در زمستان سبب افزایش پدیده وارونگی هوا در این بلوک شهری و راکد شدن هوای نزدیک زمین و در نتیجه تجمع آلاینده‌ها در سطح عابر پیاده می‌شود.
According to the increase of urban population cities are going to be high rise and compact. Meanwhile because of the presence of a large number of factories and some refineries near the city and also it's’ heavy traffic it has become one of the most polluted cities in Iran. Refer to statistics from Isfahan Meteorology center in the year of 1392 this city had 67 day with unhealthy Weather that most of this state occurred in the winter because of inversion phenomenon. In this research the effect of high rise construction and changes in the elevation of buildings in an urban block located in the center of Isfahan in 15 years ago, now and 15 years later has been evaluated by ENVI-MET software. During the winters the effects of buildings evaluation’s rise on the temperature of urban block, wind velocity in the horizontal state (pedestrian level) and the vertical movement factor has been investigated. The results show that in the winter due to the elevation increase the temperature of urban block decreases by 0.025 °C also the horizontal wind velocity (pedestrian level) increases by 0.2 m/s that is unpleasant. Meanwhile the vertical movement factor in the winters decreases due to rise in elevation. This changes in the temperature, wind velocity near the ground level and the movement factor in the winter cause increase of inversion occurrence in this urban block so air at near of the ground level.
Kolokotsa D, Psomas A, Karapidakis E, 2009, Urban heat island in southern Europe: the case study of Hania, Crete, Solar Energy, Vol 83.pp 1871–1883
Taleb D, Abu-Hijleh B, 2012, Urban heat islands: Potential effect of organic and structured urban configurations on temperature variations in Dubai, UAE. Renewable Energy, Vol 50, pp 747-762
Chao Y a, Edward N a, Leslie K, 2013, Improving air quality in high-density cities by understanding the relationship between air pollutant dispersion and urban morphologies. Building and Environment, Vol 71, pp245-258
Givoni B, 1998, Climate Considerations in Building and Urban Design, John Wiley & Sons, New York.( B Givoni - 1998 - books.google.com)
Hoppe P, 2002, Different aspects of assessing indoor and outdoor thermal comfort. Energy and Building, Vol 34, pp 661–665
Ratti C, Di Sabatin S, Britter R, 2005, Urban texture analysis with image processing techniques: winds and dispersion. Theoretical and Applied Climatology, Vol 84, pp77–90.
Toudert F, Mayer H, 2005, Numerical study on the effects of aspect ratio and orientation of an urban street canyon on outdoor thermal comfort in hot and dry climate. Building and Environment, Vol 41, pp 94–108
Thapar H, Yannas S, 2008, Microclimate and Urban Form in Dubai. Environment & Energy
Buccolieri R, Sandberg M, Di Sabatino S, 2010, City breathability as quantified by the exchange velocity and its spatial variation in real inhomogeneous urban geometries: An example from central London urban area. Atmospheric Environment, Vol 44, pp 1894-1903
Okeil A, 2010, A holistic approach to energy efficient building forms. Energy and Buildings, Vol 42(9), pp 1437-1444
Taleb H, Taleb D, 2014, Enhancing the thermal comfort on urban level in a desert area: Case study of Dubai United Arab Emirates. Urban Forestry & Urban Greening, Vol 13, pp253–260
Bruse M, 2014, www.envi-met.de.
Tong N, Leung D, 2012, Effects of building aspect ratio, diurnal heating scenario, and wind speed on reactive pollutant dispersion in urban street canyons. Journal of Environmental Sciences, Vol 24, pp 2091–2103
Nishizawa S, Sawachi T, Maruta E, 2008, Evaluation of effect of the wind pressure fluctuation for cross ventilation in the residential district. Proceedings of the Air Infiltration and Ventilation Centre Conference, Kyoto, Japan; 2008.
Eeftens M, Beekhuizen J, Beelen R, Wang M, Vermeulen R, Brunekreef B, Huss A, Hoek G, 2013, Quantifying urban street configuration for improvements in air pollution models, Atmospheric environment, Vol 72, pp 1–9
Hang J, Li Y, Sandberg M, Buccolieri R, Di Sabatino S, 2012, The influence of building height variability on pollutant dispersion and pedestrian ventilation in idealized high-rise urban areas. Building and Environment, Vol 56 ,pp 346-360
Wu W, Zhang Y, Gao J, He J, 2014, A temperature inversion-induced air pollution process as analyzed from Mie LiDAR data. Science of the Total Environment, Vol 479–480, pp 102–108
S Janha, Frans K, Olofson G, Patrik U, Pettersson A, Hallquist M, 2006, Evolution of the urban aerosol during winter temperature inversion episodes. Atmospheric Environment, Vol40, pp 5355–5366
Wallace J, Kanaroglou P, 2009, The effect of temperature inversions on ground-level nitrogen dioxide (NO2) and fine particulate matter (PM2.5) using temperature profiles from the Atmospheric Infrared Sounder (AIRS). Science of the Total Environment, Vol 407 ,pp5085–5095
Wallace J, Corr D, Kanaroglou P, 2010, Topographic and spatial impacts of temperature inversions on air quality using mobile air pollution surveys. Science of the Total Environment, Vol 408 ,pp 5086–5096
Malingowski J, Atkinson D, Fochesatto J, Cherry J, Stevens E, 2014, An observational study of radiation temperature inversions in Fairbanks, Alaska. Polar Science, Vol 8, pp 24-39
_||_Kolokotsa D, Psomas A, Karapidakis E, 2009, Urban heat island in southern Europe: the case study of Hania, Crete, Solar Energy, Vol 83.pp 1871–1883
Taleb D, Abu-Hijleh B, 2012, Urban heat islands: Potential effect of organic and structured urban configurations on temperature variations in Dubai, UAE. Renewable Energy, Vol 50, pp 747-762
Chao Y a, Edward N a, Leslie K, 2013, Improving air quality in high-density cities by understanding the relationship between air pollutant dispersion and urban morphologies. Building and Environment, Vol 71, pp245-258
Givoni B, 1998, Climate Considerations in Building and Urban Design, John Wiley & Sons, New York.( B Givoni - 1998 - books.google.com)
Hoppe P, 2002, Different aspects of assessing indoor and outdoor thermal comfort. Energy and Building, Vol 34, pp 661–665
Ratti C, Di Sabatin S, Britter R, 2005, Urban texture analysis with image processing techniques: winds and dispersion. Theoretical and Applied Climatology, Vol 84, pp77–90.
Toudert F, Mayer H, 2005, Numerical study on the effects of aspect ratio and orientation of an urban street canyon on outdoor thermal comfort in hot and dry climate. Building and Environment, Vol 41, pp 94–108
Thapar H, Yannas S, 2008, Microclimate and Urban Form in Dubai. Environment & Energy
Buccolieri R, Sandberg M, Di Sabatino S, 2010, City breathability as quantified by the exchange velocity and its spatial variation in real inhomogeneous urban geometries: An example from central London urban area. Atmospheric Environment, Vol 44, pp 1894-1903
Okeil A, 2010, A holistic approach to energy efficient building forms. Energy and Buildings, Vol 42(9), pp 1437-1444
Taleb H, Taleb D, 2014, Enhancing the thermal comfort on urban level in a desert area: Case study of Dubai United Arab Emirates. Urban Forestry & Urban Greening, Vol 13, pp253–260
Bruse M, 2014, www.envi-met.de.
Tong N, Leung D, 2012, Effects of building aspect ratio, diurnal heating scenario, and wind speed on reactive pollutant dispersion in urban street canyons. Journal of Environmental Sciences, Vol 24, pp 2091–2103
Nishizawa S, Sawachi T, Maruta E, 2008, Evaluation of effect of the wind pressure fluctuation for cross ventilation in the residential district. Proceedings of the Air Infiltration and Ventilation Centre Conference, Kyoto, Japan; 2008.
Eeftens M, Beekhuizen J, Beelen R, Wang M, Vermeulen R, Brunekreef B, Huss A, Hoek G, 2013, Quantifying urban street configuration for improvements in air pollution models, Atmospheric environment, Vol 72, pp 1–9
Hang J, Li Y, Sandberg M, Buccolieri R, Di Sabatino S, 2012, The influence of building height variability on pollutant dispersion and pedestrian ventilation in idealized high-rise urban areas. Building and Environment, Vol 56 ,pp 346-360
Wu W, Zhang Y, Gao J, He J, 2014, A temperature inversion-induced air pollution process as analyzed from Mie LiDAR data. Science of the Total Environment, Vol 479–480, pp 102–108
S Janha, Frans K, Olofson G, Patrik U, Pettersson A, Hallquist M, 2006, Evolution of the urban aerosol during winter temperature inversion episodes. Atmospheric Environment, Vol40, pp 5355–5366
Wallace J, Kanaroglou P, 2009, The effect of temperature inversions on ground-level nitrogen dioxide (NO2) and fine particulate matter (PM2.5) using temperature profiles from the Atmospheric Infrared Sounder (AIRS). Science of the Total Environment, Vol 407 ,pp5085–5095
Wallace J, Corr D, Kanaroglou P, 2010, Topographic and spatial impacts of temperature inversions on air quality using mobile air pollution surveys. Science of the Total Environment, Vol 408 ,pp 5086–5096
Malingowski J, Atkinson D, Fochesatto J, Cherry J, Stevens E, 2014, An observational study of radiation temperature inversions in Fairbanks, Alaska. Polar Science, Vol 8, pp 24-39