بررسی روند نمایه‌های دوره سرما، فصل رشد، دمای مطلق کمینه و بیشینه در استان فارس

نوع مقاله : مقاله پژوهشی

نویسندگان

1 1- کارشناس ارشد هواشناسی کشاورزی، بخش مهندسی آب، دانشکده کشاورزی، دانشگاه شیراز

2 2- دانشیار بخش مهندسی آب و مرکز پژوهش‌های جوی اقیانوسی، دانشکده کشاورزی، دانشگاه شیراز

چکیده

در این پژوهش تحلیل روند نمایه‌های دمایی هواشناسی کشاورزی در پنج ایستگاه هواشناسی در استان فارس مطالعه شد. ده نمایه هواشناسی‌کشاورزی شامل نمایه‌های دوره‌سرما (آخرین‌یخبندان‌بهاره، اولین‌یخبندان‌پاییزه، طول‌دوره‌یخبندان، تعداد‌روزهای‌یخبندان و ساعات‌سرمادهی)، نمایه‌های فصل رشد (آغاز، پایان و طول‌فصل‌رشد) و نمایه‌های دمای مطلق سالانه (کمینه و بیشینه) با استفاده از داده‌های دمای هوای بیشینه و کمینه روزانه بررسی شدند. آزمون من-کندال و تحلیل روند خطی به ترتیب برای تعیین وجود و اندازه (شیب) روند استفاده شدند. آزمون من-کندال دنباله‌ای نیز برای یافتن نقطه آغاز ناگهانی و بررسی روند در زیردوره‌ها به کار گرفته شد. روند کاهشی معنی‌دار در اغلب نمایه‌های دوره سرما در ایستگاه باجگاه (دانشکده کشاورزی) و روند افزایشی معنی دار در نمایه ساعات سرمادهی در ایستگاه شیراز مشاهده شد. در میان نمایه‌های دوره سرما، نمایه طول‌روزهای‌یخبندان بیشترین مقدار روند را دارا بود. یک روند کاهشی معنی‌دار برای طول دوره و تعداد‌روزهای‌یخبندان با شیب Day/Decade 12- و 9- از سال 1986 در باجگاه مشاهده شد. همچنین نمایه ساعات‌سرمادهی در ایستگاه‌های باجگاه و شیراز به ترتیب با شیب Hour/ Decade 68- و 66- روند کاهشی معنی‌دار داشتند. نتایج این دو ایستگاه نشان داد که شروع فصل‌رشد زودرس، تأخیر در پایان‌فصل رشد و افزایش طول دوره‌رشد رخ داده است. در اغلب نمایه‌ها نقطه تغییر روند در ایستگاه‌های باجگاه و شیراز به ترتیب در دهه 1980 و 1970 به دست آمد. همچنین تغییر روند معنی‌دار نمایه‌های کمینه و بیشینه مطلق‌سالانه در ایستگاه کوشکک دیده شد.

کلیدواژه‌ها


عنوان مقاله [English]

Trend analysis of frost period, growing season, absolute minimum and maximum temperature in Fars province

نویسندگان [English]

  • Sousan Esfandiari 1
  • Amin Shirvani 2
1 Irrigation Dep., Agriculture Faculty, Shiraz University, Shiraz, Iran
2 Shiraz University
چکیده [English]

Agricultural productions and management strategies can be highly affected by long term changes and variability in temperature. Agrometeorological indices are commonly used to evaluate how weather and climate conditions affect crop production. The extreme temperature-based indices are important tools for monitoring agrometeorological indices. In this study, trend analysis of extreme temperature-based agrometeorological indices for five stations including Abadeh, Fasa, Shiraz, Badjgah and Kooshkak in Fars province was studied. The Abadeh, Fasa, Shiraz stations are synoptic stations and Badjgah and Kooshkak stations are agrometeorological stations. Ten indices including frost indices (last spring frost, first fall frost, length of frost period, number of frost days and chilling hours), growing season indices (start, end and length of growing season) and annual absolute temperature indices (minimum and maximum temperature) were investigated in the present study. Using daily minimum and maximum temperature data, time series of these ten indices were separately produced over a long period. The autocorrelation function for these constructed time series were plotted and used to check serially correlated time series indices. For each station, those time series indices, which were serially correlated, were transformed to produce an uncorrelated pre-whitened time series. For example, last spring frost in Shiraz station, and start of growing season in Badjgah station were serially correlated and it is necessary to be pre-whitened. The autocorrelation function for all indices in Kooshkak station have indicated that all correlations were statistically insignificant and therefore no necessary to pre-whitening. The nonparametric Mann-Kendal test which is commonly used to trend analysis was used to determine the existence of trend in time series agrometeorological indices. The linear trend which is commonly applied to quantify time series changes was applied to determine the amount (slope) of time series agrometeorological indices. The sequential Mann-Kendal test was also applied to determine initiation of abrupt trend changes and explore in sub-periods of time series agrometeorological indices. The applied sequential Mann-Kendal test indicated a significant jump in the air temperature at Fasa station in 1984. This station had a re-location in 1984 (personal communication with Fasa station). Therefore, the Fasa station was removed for further analysis in this study. This was also applied to determine initiation of abrupt trend changes and explore in sub-periods of time the results of both Mann-Kendall and linear trend indicated that the trends of time series agrometeorological indices were different for various stations.

A significant decreasing trend was observed for most frost indices in Badjgah station, which is an agrometeorological station at agriculture collage of Shiraz University. A significant decreasing trend, at 5% significance level, was observed for length of period and number of frost days, respectively, with -9 and -12 Day/Decade slope in Badjgah from 1986 such that the length of frost period and number of frost days had largest decreasing trend among frost indices. Also, a significant decreasing linear trend were observed for chilling hours in Badjgah and Shiraz stations with -68 and -66 Hour/ Decade slope. For all growing season indices trend existence was observed in Badjgah and Shiraz stations, except start of growing season in Badjgah. An earlier start, delay in end, and increasing in the length of growing season were observed in both Badjgah and Shiraz stations. For most indices, a change was occurred in 1970s and 1980s in Badjgah and Shiraz, respectively. A significant trend in the annual absolute maximum and minimum temperature was observed in Kooshkak station (near to Marvdasht) using the Mann-Kendall analysis at 5% significance level. In this station, a change had occurred in the absolute annual minimum temperature in 1992. In the other hand, after 1979 a change had occurred in the absolute annual maximum temperature in Kooshkak station. A significant downward trend for Absolute minimum temperature has been started from 1999 and this trend has continued up to the end of studied year.

For each station, the studied indices were indicated different trends and beginning time. A significant trend was observed in all of frost period and growing season indices at Badjgah station. The information of first fall frost and last spring frost is vital for harvest and planning crops. Decreasing trend of chilling hours in Shiraz and Badjgah stations have indicated that dormancy period is longer and plants need more time to exit from dormancy period.

کلیدواژه‌ها [English]

  • Trend
  • agrometeorological indices
  • sequential Mann-Kendal test
  • change point
  1.  

    1. Abtahi, M., Safe, M. (2012). Rain and temperature trends in Namak lake basin (Iran) during the last half- century. International Journal of Science and Nature. 3: 137-146.
    2. Azizi, Gh., Roshani, M. (1387). The study of Climate change in south coast Caspian Sea using
      Mann-Kendall technique. Physical Geography Research. 68: 13-24.
    3. Bootsma, A. (1994). Long term (100 yr) climatic trends for agriculture at selected locations in Canada. Climatic Change. 26(1), 65-88.
    4. Erlat, E., Türkeş M. (2011). Analysis of observed variability and trends in numbers of frost days in Turkey for the period 1950–2010. International Journal of Climatology. 32 (12): 1889-1898.
    5. Darand, M. (1392). Evaluation of Changes in Extreme Temperature Indices Over the Kurdistan Province During Last Half Century.  Journal of Natural Environment Hazards. 2: 75-92.
    6. Easterling, D. R., (2002). Recent changes in frost days and the frost-free season in the United States. Bulletin of the American Meteorological Society. 83 (9). 1327-1332.
    7. Fernández-Long, M.E., Müller, G. V., Beltrán-Przekurat, A., Scarpati, O. E., (2012). Long-term and recent changes in temperature-based agroclimatic indices in Argentina. International Journal of Climatology. 33 (7): 1673–1686.
    8. Frich, P., Alexander, LV. Della–Marta, P., Gleason, B., Haylock., M., Tank, K., Teterson, T., (2002). Observed coherent changes in climatic extremes during the second half of the twentieth century. Climatic Change. 19: 193–212.
    9. Ghorbani, Kh., Valizadeh, E. (1393). Studying frost and chilling dates affecting agriculture under climate change (Case study: Mashhad, Tabriz and Qazvin). Journal of Water and Soil Conservation. 21: 197-214.
    10. Gocic, M., Trajkovic, S. (2013). Analysis of changes in meteorological variables using Mann-Kendall and Sen's slope estimator statistical tests in Serbia. Global and Planetary Change.100: 172–182.
    11. Hamed, K.H., Rao, A.R., (1998). A modified Mann–Kendall trend test for autocorrelated data. Journal of Hydrology. 204: 182–196.
    12. Jahandideh, M., Shirvani, A., (1391). Trend Analysis for the Precipitation Time Sub-Series in Fars Province.  Water Engineering. 5: 73-84.
    13. Katz, R. W., Brown, B. G. (1992). Extreme events in a changing climate: Variability is more important than averages. Climatic Change. 21: 289–302.
    14. Koocheki, A., Nassiri Mahallati, M., Jafari, L. (1394). Evaluation of Climate Change Effect on Agricultural Production of Iran: I. Predicting the Future Agroclimatic Conditions. Iranian Journal of Field Crops Research. 13: 651-664.
    15. Lashkari, H., Keikhosravi, Gh., (1396). Changing Temperature Trend and zoning beginning, end of the Glacial in Tehran.  Journal of Natural Environment Hazards. 6: 63-86.
    16. Li, Z., Zhen, F. L. Liu., W. Z. Flanagan, D. C. (2010). Spatial distribution and temporal trends of extreme temperature and precipitation events on the Loess Plateau of China during 1961–2007. Quaternary International, 226(1): 92-100.
    17. Mearns, L. O., Katz, R. W., Schneider, S. H., (1984.) Extreme high-temperature events: Changes in their probabilities with changes in mean temperature. Journal of Applied Meteorology.23: 1601–
    18. Menzel, A., Jakobi, G., Ahas, R., Scheifinger, H., Estrella, N., (2003). Variations of the climatological growing season (1951–2000) in Germany compared with other countries. International Journal of Climatology. 23(7): 793-812.
    19. Moonen, AC., Ercoli, L., Mariotti, M., Masoni, A., (2002). Climate change in Italy indicated by agrometeorological indices over 122 years. Agricultural and Forest Meteorology. 111: 13–27 DOI: 10.1016/S0168-1923 (02) 00012-6.
    20. Mohamadi, H., Taghavi, F., (1384). Precipitation and temperature extreme indices trend in Tehran. Physical Geography Research. 53: 151-172.
    21. Pascale, A.J., Damario, E.A., (2004). Bioclimatolog´ıaAgr´ıcolay Agroclimatolog ´ıa. Editorial Facultad de Agronom´ıa – Universidad de Buenos Aires: Buenos Aires, 550 PP.
    22. Potop, V., Zahranicek, P., Tuerkott, L., Stepanek, P., Soukup, J., (2014). Risk analysis of the first and last frost occurrences during growing season of vegetables in the Elbe River lowland. IDOJARAS, 118(1): 1-17.
    23. Rahimzadeh, F., Asgari, A., Fattahi, E., (2009). Variability of extreme temperature and precipitation in Iran during recent decades. International Journal of Climatology.29.3: 329-343.
    24. Rezaei, P., Abed, H., (1389). Investigating the Freezing Trend Variation in Guilan Focusing on the Minimum Temperature. Geography And Environmental Studies. 1: 39-48. ‏
    25. Sayemuzzaman, M., Jha, M. K., (2014). Seasonal and annual precipitation time series trend analysis in North Carolina, United States. AtmosphericResearch.137: 183-194.
    26. Scheifinger, H., Menzel, A., Koch, E., Peter, C., (2003). Trends of spring time frost events and phenological dates in Central Europe. Theoretical and Applied Climatology. 74(1), 41-51.
    27. Schwartz, MD., Rein, A., Anto, A., (2006). Onset of spring starting earlier across the northern hemisphere. Global Change Biology. 12:343–351, DOI: 10.1111/j.1365–2486.2005.01097.
    28. Shen, S. S. P., Yin, H., Cannon, K., Howard A., Chenter, S., (2005). Temporal and spatial changes of the agroclimate in Alberta, Canada, from 1901 to 2002. Journal of Applied Meteorology. 44(7): 1090-1105.
    29. Shirvani, A., (2015). Change point analysis of mean annual air temperature in Iran. Atmospheric Research.160: 91-98.
    30. Skaggs, K.E., Irmak, S. (2012). Long-Term Trends in Air Temperature Distribution and Extremes, Growing Degree Days, and Spring and Fall Frosts for Climate Impact Assessments on Agricultural Practices in Nebraska. Journal of Applied Meteorology and Climatology. 51: 2060–2073.
    31. Sneyers, R., (1990). On the statistical analysis of series of observations. World Meteorological Organization. Technical Note 143, Geneva, Switzerland.
    32. Sohrabi, M., Ryu, H., Alijani, B., (2013). Spatial and Temporal Analysis of Climatic Extremes in the Mountainous Regions of Iran. The International Journal of climate change. 4: 18-36.
    33. Stocker, T.F, Qin. D., Plattner. G. K., Tignor, M., Allen, S.K., Boschung, J., Nauels, A., Xia, Y., Bex, V., Midgley, P.M., (2013). Climate Change. The physical science basis. Intergovernmental Panel on Climate Change. Working Group, I Contribution to the IPCC Fifth Assessment Report (AR5). Cambridge University Press. New York.
    34. Tabari, H., Hosseinzadeh Talaee, P. (2011). Analysis of Trends in Temperature Data in Arid and Semi-Arid Regions of Iran. Global and Planetary Change. 79: 1-10.
    35. Trenberth, KE., Jones, PD., Ambejnje, P., Bojariu, R., Easterling, D., Klein, Tank, A., Parker, D., Rahimzadeh, F., Renwic., JA., Rusticucci, M., Soden, B., Zhai, P. (2007). Observations: Surface and Atmospheric Climate Change. In The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change Solomon S Qin D Manning M Chen Z Marquis M Averyt KB Tignor M Miller HL(eds). Cambridge University Press: Cambridge. U.K. 987pp.
    36. Zarenistanak, M., Dhorde, A., G., Kripalani, R. H. (2014). Temperature analysis over southwest Iran: trends and projections. Theoretical Applied Climatology. 116.1-2: 103-117.