اثر گسترش شهر بر شرایط آب و هوایی ایستگاه سینوپتیک مهرآباد

نوع مقاله : مقاله کامل

نویسندگان

1 دکترای اقلیم‏شناسی، پژوهشگر دانشگاه صنعتی مالک اشتر

2 استادیار اقلیم‏شناسی، دانشکدة جغرافیا، دانشگاه تهران

چکیده

تحقیق حاضر با هدف بررسی اثر گسترش شهرنشینی و تغییر کاربری شهر تهران بر شرایط اقلیمی ایستگاه سینوپتیک مهرآباد انجام شده است. برای اجرای این کار، داده‏های روزانة بارش، بیشینة دما، و کمینة دما طی دورة 1966-2016 از سازمان هواشناسی کشور اخذ شد. پس از کنترل کیفی داده‏ها، برای بررسی شرایط اقلیمی، نخست از آزمون من‏– کندال استفاده شد و در مرحلة بعد با استفاده از نرم‏افزار RClimDex تغییرات و روند 23 شاخص حدی اقلیمی، متشکل از شاخص‏های دوره‏ای، مطلق، مبتنی بر صدک، و آستانه‏ای متغیرهای دما و بارش روزانه استخراج شد. نتایج نشان داد همگام با افزایش جمعیت و رشد فیزیکی شهر تهران و قرارگیری ایستگاه سینوپتیک مهرآباد در محدودة شهری، هر دو پارامتر دمای کمینه و بیشینه در طی دورة آماری 1966-2016 از روند افزایشی برخوردار است؛ به‏طوری‏که دمای کمینة ایستگاه مهرآباد در دورة 1966-1975 حدود 9/10 درجة سانتی‏گراد بوده و در دورة 2005-2015 به حدود 7/13 درجة سانتی‏گراد افزایش یافته است. از نظر ‏شاخص‏های حدی، افزایشی قابل ملاحظه در ‏شاخص‏های حدی سرد و افزایش در ‏شاخص‏های حدی گرم وجود دارد. شاخص روزهای سرد، شب‏‏های سرد، روزهای همراهِ یخبندان، روزهای یخی با کاهش مواجه‏اند.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

The Effect of Urban Expansion on Climate Conditions of Mehrabad Synoptic Station

نویسندگان [English]

  • Firuz Ranjbar 1
  • Masoumeh Moghbel 2
1 PhD in Climatology, Researcher at Malek Ashtar University of Technology, Iran
2 Assistant Professor of Climatology, Faculty of Geography, University of Tehran, Iran
چکیده [English]

Introduction
The UN Population Demographics in 2014 has indicated that there is a reversal of the demographic trend of urban and rural areas, with the world's largest population (54%) living in urban areas. This trend is increasing, while by the year 1990, a small population lived in the cities. This undocumented development leads to major changes in the environment including a reduction in natural surfaces and the replacement of them by artificial and human land covers. Urban areas are often identified with impenetrable and constructional surfaces that often have a negative impact on ecosystems. Urbanization changed the natural landscape into built areas of completely different physical characteristics. The transformation in surface land covers has an important effect on energy balance and local climate. As a result, urban climate is formed from the climatic factors of the city that are changing with the impact of urban factors over time.
Materials and methods
In order to study the effects of urban expansion on climatic condition of Tehran, we extracted daily precipitation, minimum and maximum temperature data from Mehrabad synoptic station during a period of 50 statistical periods (1966-2016). Different methods and tests have been used to analyze trends and changes in climatic conditions. The trend in the cluster data series was studied using the Mann-Kendall test. The Mann-Kendall test is a base-rating nonparametric test for trend analysis which was first used by Mann for public applications in 1945 and revised by Kendall in 1948 and presented in a different way. Then, RClimDex software was used to extract the process of extreme weather indicators. This software has been developed by Zheng and Yang (2004 & 2005) at the Canadian Weather Service's Climate Research Branch. In the present study, 23 indicators of ETCCDI indicators were used using RClimDex. The indicators are divided into five groups based on percentiles, periodic indicators, absolute indices, threshold indicators and other indices such as temperature change overnight.
Results and discussion 
Based on non-graphical Mann-Kendall Test, both temperature parameters (minimum and maximum temperatures) have an increasing trend during the 1966-2016 period, which is more evident at the minimum temperature; while precipitation in the same period of time has been a slight downward trend. Based on the Mann-Kendall graphical test, when there is a significant trend in data, the lines ui and u'i interrupt each other. The results of the Man-Kendall test show that the increase in minimum temperature is higher than the maximum temperature. Moreover, during 1976-1986, Tehran experienced rapid physical growth and this period is coincided with an increase in temperature, which continued until the end of the period. Based on the analysis of the temperature extremes index, the cold day indices (TX10p) are facing a downward slope. On the other hand, the Hot Days Index (TX90p) faces an upward slope in the period of 1966-2016. In fact, it can be concluded that during the study period, the percentage of hot days in the Mehrabad station has an increasing trend and that of cold days has a decreasing trend. These results are consistent with the studies of Rahimzadeh et al. (2011), Niw et al. (2006) and Brown et al., 2010, on the trend of the temperature range of the night temperature.
Conclusion
In recent years, the spread of cities and their growth has had a great impact on the environmental conditions in different parts of the world. In the meantime, some cities have been experiencing rapid and significant growth. Urban change has today had widespread effects on urban climatic conditions. One of these effects is the change in the temperature of the cities (formation of the UHI) and the increase in night temperatures. The present research was carried out to investigate the effects of the expansion of Tehran on the climatic conditions of the Mehrabad synoptic station. The study of the climate conditions of the Mehrabad station shows that during the study period, the air temperature of the Mehrabad station has undergone a change. Thus, the minimum and maximum temperature is facing an increasing trend, which is, of course, more severe at the minimum temperature. The average minimum temperature of the Mehrabad station during the 1996-75 period was about 10.9 ° C, reaching about 13.7 ° C in the period 2005-2015. On the other hand, the average maximum temperature during the 1975-1996 periods was about 5.5 ° C 22 ° C. In the period 2015-2005, it reached about 23.6 ° C. In addition to temperature averages, temperature indices have also changed significantly at Mehrabad station so that cold and warm extreme events have decreasing and increasing trends, respectively. 

کلیدواژه‌ها [English]

  • Precipitation
  • temperature
  • extreme indices
  • urban expansion
  • Tehran
احمدی، ف. و رادمنش، ف. (1393). بررسی روند تغییرات متوسط دما‏ی ماهانه و سالانة نیمة شمالی کشور در نیم قرن اخیر، نشریة آب و خاک، 4: 855-865.
باقرپور، م.؛ سیدیان، س.م؛ فتح‏آبادی،ا. و محمدی، ا. (1396). بررسی کارایی آزمون من‏- کندال در شناسایی روند سری‏های دارای خودهمبستگی، نشریة علوم و مهندسی آبخیزداری ایران، 3: 11-22.
حجازی‏زاده، ز. و پروین، ن. (1388). بررسی تغییرات دما و بارش تهران طی نیم قرن اخیر، جغرافیا و برنامه‏ریزی منطقه‏ای، 43-56.
درگاه ملی آمار (https://www.amar.org.ir)
رجبی، آ. و سفاهن، ا. (1389). مدل گسترش فضایی کلان‏شهر تهران، دانشنامه، 3: 57-70.
رحیم‏زاده، ف.؛ دزفولی، ه. و پوراصغریان، آ. (1390). ارزیابی روند و جهش نمایه‏های حدی دما و بارش استان هرمزگان، مجلة جغرافیا و توسعه، 21: 97-116.
رنجبر سعادت‏آبادی، ع.؛ علی‏اکبری بیدختی، ع.ب. و صادقی حسینی، ع. (1384). آثار جز‏یرة گرما‏یی و شهرنشینی رو‏ی وضع هوا و اقلیم محلی در کلان‏شهر تهران بر اساس داده‏ها‏ی مهرآباد و ورامین، مجلة محیط‏شناسی، 39: 59-68.
رنجبر سعادت‏آبادی، ع. و آزادی، م. (1384). بررسی تغییرات میدان‏های دما و باد در کلان‏شهر تهران ناشی از توسعة شهری، تحقیقات جغرافیایی، 1(76): 171-188.
روشنی، م. (1382). بررسی تغییرات اقلیم سواحل جنوبی در‏یا‏ی خزر، پایان‏نامة کارشناسی ارشد، دانشکدة جغرافیا، دانشگاه تهران.
شمسی‏پور، ع.ا.؛ عزیزی، ق.؛ کریمی احمدآباد، م. و مقبل، م. (1392). مطالعة الگوی دمای سطوح فیزیکی در شرایط جوی متفاوت، مجلة پژوهش‏های جغرافیای طبیعی، 46(1): 59-76.
صادقی‏نیا، ع.ر.؛ علیجانی، ب. و ضیائیان، پ. (1391). ﺗﺤﻠﻴﻞ ﻓﻀﺎﻳﻲ- ﺣﺮارﺗﻲ زﻣﺎﻧﻲ ﺟﺰﻳﺮة ﻛﻼن‏ﺷﻬﺮ ﺗﻬﺮان ﺑﺎ اﺳﺘﻔﺎده از ﺳﻨﺠﺶ از دور و ﺳﻴﺴﺘﻢ اﻃﻼﻋﺎت ﺟﻐﺮاﻓﻴﺎﻳﻲ، جغرافیا و مخاطرات محیطی، 4: 1-17.
عطایی، ه. و فنایی، ر. (1392). ﺑﺮرﺳﻲ روﻧﺪ ﺗﻐﻴﻴﺮ ﺳﺮ‏ی‏ﻫﺎ‏ی دﻣﺎ‏ی ﺷﻬﺮ ﺷﻴﺮاز در ارﺗﺒﺎط ﺑﺎ ﺑﺮﻧﺎﻣﻪ‏رﻳﺰ‏ی ﺗﻮسعة ﺷﻬﺮ‏ی، مجلة پژوهش و برنامه‏ریزی شهری، 4(15): 57-76.
علیجانی، ب. و فرج‏زاده، ح. (1394). تحلیل روند شاخص‏های دمای فرین در شمال ایران، نشریة جغرافیا و برنامه‏ریزی، 52: 229-256.
فتحی، ا. (1394). روند شهرنشینی در ایران، مجلة آمار، 2: 8-15.
قرخلو، م. و زنگنه شهرکی، س. (1388). شناخت الگو‏ی رشد کالبد‏ی-‏ فضایی شهر با استفاده از مدل‏ها‏ی کمی (مطالعة مورد‏ی: شهر تهران)، مجلة جغرافیا و برنامه‏ر‏یز‏ی محیطی، 20(3): 40-19.
محمدی، ح. و تقوی، ف. (1384). روند شاخص‏های حدی دما و بارش در تهران، مجلة پژوهش‏های جغرافیایی، 53: 121-172.
مزیدی، ا. و نارنگی فرد، م. (1395). تأثیر توسعة شهری و تغییرات کاربری بر عناصر آب و هوایی شهر شیراز و فسا، نشریة تحقیقات کاربردی علوم جغرافیایی، 16(40): 131-154.
مقبل، م. (1388). بررسی تأثیر گرمایش جهانی بر نوسانات سطح آب دریای خزر (مطالعة موردی: غرب دریای خزر)، پایان‏نامة کارشناسی ارشد، دانشکدة جغرافیا، دانشگاه تهران.
Ahmadi, F. and Radmanesh, F. (2014). Trend Analysis of Monthly and Annual Mean Temperature of the Northern Half of Iran Over the Last 50 Years, Journal of Water and Soil, 28: 855-865.
Alijani, B. and Farajzadeh, H. (2015). The trend analysis of the extreme temperatures in northern Iran, Geography and Planning, 52: 229-256.
Atayi, H. and Fanayi, R. (2013). Investigation of the trend of temperature changes in Shiraz city in relation to urban development planning, Research and urban Planning, 15: 57-76.
Bagherpoor, M.; Seyedian, S.M.; Fathabadi, A.H. and Mohamadi, A. (2017). Study of Mann-Kendall Test Performance in Detecting the Series of Autocorrelation, Iran-Watershed Management Science & Engineering, 11(36): 11-22.
Brown, P. J.; Bradley, R. S.; Keimig, F. T. (2010). Changes in extreme climate indices for the northeastern United States, 1870–2005. Journal of Climate23(24), 6555-6572.
Cai, D.; Fraedrich, K.; Guan, Y.; Guo, S. and Zhang, C. (2017). Urbanization and the thermal environment of Chinese and US-American cities, Science of the Total Environment, 589: 200-211.
Fathi, A. (2015). Urbanization process in Iran, Statistics, 2: 8-15.
Gharakhlou, M. and Zanganeh Shahraki, S. (2009). Recognition of spatial-physical growth of the city using quantitative models (a case study of Tehran), Geography and Environmental Planning, 3: 19-40.
Hejazizadeh, Z. and Parvin, N. (2010). Study on changes in Tehran's temperature and precipitation over the recent century, Geography and regional planning, pp. 43-56.
Hua, L.J.; Ma, Z.G. and Guo, W.D. (2008). The impact of urbanization on air temperature across China, Theoretical and Applied Climatology, 93(3-4): 179-194.
Mazidi, A. and Narengi Fard, M. (2016). The Effect of Urban Development and Land Use Changes on Climate Elements in Shiraz and Fasa, Journal of Apllied Researches in Geographical Sciences, 40: 131-154.
Moghbel, M. (2009). The Impact of Global Warming on Caspian Sea Water Level Fluctuations, MSc Thesis, Faculty of geography, University of Tehran.
Moghbel, M. and Salim, R.E. (2017). Environmental benefits of green roofs on microclimate of Tehran with specific focus on air temperature, Humidity and CO 2 content, Urban Climate, 20: 46-58.
Mohammadi, H. and Taghavi, F. (2005). The trend of extreme temperature and precipitation parameters in Tehran, Physical Geography Research Quarterly, 53: 121-172.
Mohan, M. and Kandya, A. (2015). Impact of urbanization and land-use/land-cover change on diurnal temperature range: A case study of tropical urban airshed of India using remote sensing data, Science of the Total Environment, 506: 453-465.
Morabito, M.; Crisci, A.; Messeri, A.; Orlandini, S.; Raschi, A.; Maracchi, G. and Munafò, M. (2016). The impact of built-up surfaces on land surface temperatures in Italian urban areas, Science of The Total Environment, 551: 317-326.
New, M.; Hewitson, B.; Stephenson, D. B.; Tsiga, A.; Kruger, A.; Manhique, A.; ... & Mbambalala, E. (2006). Evidence of trends in daily climate extremes over southern and west Africa. Journal of Geophysical Research: Atmospheres111(D14).
Qiao, Z.; Tian, G. and Xiao, L. (2013). Diurnal and seasonal impacts of urbanization on the urban thermal environment: a case study of Beijing using MODIS data, ISPRS journal of photogrammetry and remote sensing, 85, 93-101.
Rahimzadeh, F.; Dezfoli, H. and Pour Asgharian, A. (2011). Evaluation of trend and mutation of extreme temperature and precipitation indexes in Hormozgan province, Geography and Development, 21: 97-116.
Rajabi, A. and Safahen, A. (2010). Spatial expansion of Tehran metropolis, Daneshnameh, 3: 57-70.
Ranjbar Saadatabadi, A. and Azadi, M. (2005). Investigation of changes in temperature and wind fields in Tehran city due to urban development, Geographical researches, 1(76): 171-188.
Ranjbar Saadatabadi, A.; Aliakbari bidokhti, A.A. and Sadeghi Hosseini, S.A. (2005). The effects of urban heat island and urbanization on the local climate and weather of Tehran metropolis based on Mehrabad and Varamin data, Journal of Environmental Studies, 39: 59-68.
Ren, G. and Zhou, Y. (2014). Urbanization effect on trends of extreme temperature indices of national stations over Mainland China, 1961–2008, Journal of climate, 27(6): 2340-2360.
Ren, G.; Zhou, Y.; Chu, Z.; Zhou, J.; Zhang, A.; Guo, J. and Liu, X. (2008). Urbanization effects on observed surface air temperature trends in North China, Journal of Climate, 21(6): 1333-1348.
Roshani M. (2001). Investigating the Climate Change of the South Coast of the Caspian Sea, MSc Thesis, Faculty of geography, University of Tehran.
Sadeghinia, A.R.; Alijani, B. and Ziaeian, P. (2012). Spatial-temporal analysis of UHI in Tehran metropolitan area using remote sensing and GIS, Geography and Environmental Disasters, 4: 1-17.
Shamsipour, A.A.; Azizi, GH.; Karimi Ahmadabad M. and Moghbel, M. (2013). Study on physical surfaces temperature pattern in different weather condition, Physical Geography Research Quarterly, 1: 59-76.
Sillmann, J.  and Roeckner, E. (2008). Indices for extreme events in projections of anthropogenic climate change, Climatic Change, 86: 83-104.
Tam, B.Y.; Gough, W.A. and Mohsin, T. (2015). The impact of urbanization and the urban heat island effect on day to day temperature variation, Urban Climate, 12: 1-10.
Zhang, X., & Yang, F. (2004). RClimDex (1.0) user manual. Climate Research Branch Environment Canada, 22.
Zhang, X. et al. (2005). Trends in Middle East climate extreme indices from 1950 to 2003, Journal of Geophysical Research, Vol. 110.