ویژگی‌های بارش زراعی و فرین‌های آن در استان مرکزی در دوره آماری 1371-1370 تا 1400-1399

نوع مقاله : مقالات پژوهشی

نویسندگان

• سکینه خان سالاری ¹
• محمود امیدی ²
• مژگان فلاح زاده ²

¹ پژوهشگاه هواشناسی و علوم جوّ، تهران، ایران

² اداره کل هواشناسی استان مرکزی، اراک، ایران

https://doi.org/10.22067/jsw.2023.84421.1332

چکیده

با توجه به گرمایش جهانی و تغییر اقلیم و افزایش خشکسالی و رخدادهای بارشی فرین، آشنایی با ویژگی­های بارش منطقه به منظور مدیریت منابع آب، به­ویژه در زمان وقوع بارش­های سیل­آسا و تبدیل خطرآفرینی این رخدادها به افزایش ذخایر آبی با مدیریت صحیح از اهمیت ویژه­ای برخوردار است. در پژوهش حاضر ویژگی­های بارش در استان مرکزی در دوره آماری 30 ساله (از سال زراعی 1371-1370 تا 1400-1399) با روش­های آماری، مورد تحلیل و سپس با نرم افزارArcGIS  توزیع مکانی آنها ترسیم و بررسی شد. همچنین روند تغییرات بارش در مقیاس زمانی ماهانه، فصلی و سالانه با استفاده از آزمون من-کندال مورد مطالعه قرار گرفت. علاوه بر این بارش فرین بااستفاده از چهار شاخص بارش فرین شامل مجموع بارش فرین (R95p)، تعداد روزهایی که در سال مورد بررسی، مقدار بارش در آنها از آستانه بارش فرین آن ایستگاه بیشتر باشد (R95d)، شدت مطلق بارش فرین (AEPI) و کسری از کل بارندگی ناشی از رخدادهای فراتر از آستانه بارش فرین (R95pT) که بیانگر نسبت بارش فرین به بارش سالانه در روزهای بارانی (بارش روزانه بیش از یک میلی­متر) است، مورد تحلیل و بررسی قرار گرفت. نتایج این مطالعه نشان می­دهد به‌طور متوسط بیشینه شاخص R95pT، 53 درصد از بارش سال را شامل می­شود که در صورت آگاهی از زمان وقوع این فرین­ها مدیریت سیلاب­ها و استفاده بهینه از منابع آبی از نتایج آن است که بیش از 20 درصد این بارش­های فرین در فروردین ماه رخ داده است. در این راستا طبق بررسی توزیع مکانی بارش در استان مرکزی، بیشینه وقوع مقدار میانگین بارش سالانه و فصلی به استثنای فصل تابستان در جنوب­غرب و کمینه آن در مناطق شرقی استان مرکزی قرار دارد و به­طور متوسط بیشترین بارش در فصل زمستان و سپس در بهار و پاییز رخ داده است. همچنین فروردین­ماه با ضریب تغییرات 8/0 و میانگین بارش ماهانه در طول دوره آماری مورد مطالعه برابر با 6/55 میلی­متر پربارش­ترین ماه است و به دلیل وقوع اکثر بارش­های فرین در این ماه بیشترین ارزش ذخیره­سازی و مدیریت آب را در بین ماه­های سال را دارد. همچنین از دیدگاه مقدار بارش میانگین ماهانه، بعد از فروردین ماه، به­ترتیب ماه­های آذر، اسفند و آبان با میانگین بارش ماهانه 3/39، 2/38 و 3/36 میلی­متر در اولویت مدیریت ذخیره­سازی آب قرار دارند. نتیجه بررسی روند تغییرات بارش ماهانه، فصلی و سالانه با استفاده از آزمون ناپارامتریک من-کندال روند یکپارچه­ای را نشان نمی­دهد اما می­توان در حالت کلی گفت تقریبا در اکثر ایستگاه­های هواشناسی استان مرکزی که مورد مطالعه قرار گرفته­اند حداقل در سطح اطمینان 90% در بارش بهمن ماه روند کاهشی معنی­دار وجود دارد. نتایج بررسی شاخص­های بارش فرین بیانگر وقوع بیشترین مقدار آستانه بارش فرین در ایستگاه شازند (28 میلی­متر) و کمترین آن در ایستگاه ساوه (15 میلی­متر) است.

کلیدواژه‌ها

• استان مرکزی
• ویژگی‌های بارش
• بارش فرین
• گرمایش جهانی
• شاخص‌های بارش فرین

موضوعات

• هواشناسی کشاورزی

عنوان مقاله [English]

Analysis of Crop Precipitation and Its Extreme Events in Markazi Province During the Statistical Period of 1991-1992 to 2020-2021

نویسندگان [English]

• Sakineh Khansalari ¹
• Mahmood Omidi ²
• Mozhgan Fallahzadeh ²

¹ Atmospheric Science and Meteorological Research Center, Tehran, Iran

² Markazi Province Meteorological Administration, Arak, Iran

چکیده [English]

Introduction
Due to global warming and climate change, droughts and extreme precipitation events are increasing. Therefore, it is of special importance to know the characteristics of precipitation in the region in order to manage water resources effectively especially during torrential rainfall events. This can help to reduce the risk of these events and increase water reserves with proper management. These precipitation characteristics which are the objectives of the present study, include the temporal-spatial distribution of precipitation in different parts of the study area, as well as the number of days with and without precipitation and the maximum precipitation occurring in the region. Also, these precipitation characteristics should give us information about extreme precipitation events.
 
Materials and Methods
This research analyzed the characteristics of precipitation in Markazi province over a 30-year period (from the crop year 1991-1992 to 2020-2021) using statistical methods and the spatial distribution was drawn and analyzed with ArcGIS software. This province includes the 12 meteorological stations of Arak, Mahalat, Saveh, Tafresh, Ashtiyan, Komeijan, Khondab, Shazand, Khomein, Delijan, Farmahin and Gharqabad, which the precipitation data of these stations were investigated. The trend of precipitation changes in monthly, seasonal, and annual time scales were also examined using the Mann-Kendall test. Moreover, extreme precipitation was assessed using four indices: total extreme precipitation (R95p), number of days with precipitation above the station’s extreme precipitation threshold (R95d), absolute intensity of extreme precipitation (AEPI) and the fraction of total rainfall from events exceeding the extreme threshold (R95pT). The latter index represents the ratio of extreme precipitation to annual precipitation in rainy days (daily rainfall above 1 mm).
 
Results and Discussion
This study reveals that, on average, 53% of the annual precipitation is accounted for by the maximum index of R95pT, which indicates the percentage of extreme precipitation that occurred at each station relative to its the precipitation of the corresponding year. Knowing the timing of these extreme events can help to manage floods and optimize water resources. More than 20% of these precipitations occurred in March. The spatial distribution of rainfall in Markazi province shows that the south-west regions have the highest average annual and seasonal rainfall, except for the summer season, while the eastern regions have the lowest. The winter season has the highest rainfall on average, followed by spring and autumn. March is the rainiest month with a coefficient of variation of 0.8 and an average monthly rainfall of 55.6 mm during the studied period. Due to most extreme precipitation events occurring in this month, it has the highest importance for water storage and management throughout the year. The average precipitation in March ranges from 32.6 mm (Saveh station) to 91.6 mm (Shazand station) across the stations of the province. The maximum rainfall in this month varies from 124.4 to 254.6 mm among the stations of the Markazi province, which is a considerable amount compared to the provincial average crop year. The standard deviation of precipitation in this month is between 28.7 and 61.3 mm, and the coefficient of variation at the stations of the province is between 0.6 and 0.9. Moreover, in terms of average monthly rainfall 22Nov-21Dec, 20Feb-19Mar, and 23Oct-21Nov are the next priority months for water storage management after 20Mar-19Apr, with average monthly rainfall of 39.3, 38.2, and 36.3 mm, respectively. The Mann-Kendall non-parametric test results did not reveal a consistent trend, but it showed that most of the meteorology stations in Markazi province had a significant decreasing trend in the rainfall in 21Jan-19Feb at a 90% confidence level. The analysis of extreme precipitation indices indicated that Shazand station had the highest extreme precipitation threshold value (28 mm), while Saveh and Delijan stations had the lowest (15 mm). The extreme precipitation threshold average of 30 years in other meteorological stations of Markazi province are 21mm in Arak, 17mm in Tafresh, 21mm in Khomeyn, 19mm in Mahallat, 17mm in Komeijan, 16mm in Farmahin, 21mm in Khondab, 17mm Gharqabad and 18mm in Ashtiyan.
 
Conclusion
The spatial distribution of rainfall in Markazi Province shows that the southwest regions have the highest average annual and seasonal precipitation, except for summer, while the east regions have the lowest. The average monthly rainfall also indicates that March has the highest rainfall among all months of the year, and that about 20% of the annual extreme precipitation occurs in this month.

کلیدواژه‌ها [English]

• Characteristics of precipitation
• Extreme precipitation
• Global warming
• Extreme precipitation indices
• Markazi province

©2023 The author(s). This is an open access article distributed under Creative Commons Attribution 4.0 International License (CC BY 4.0), which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source.

مراجع

1. Alizadeh, A. (2015). Principles of applied hydrology, Imam Reza University Publications.
2. Ataee, H., & Fanaee, R. (2012). Studying the climate change of Markazi province by Mann-Kendall method. Nivar, 36(77-76), 37-48.
3. Behnia,R. (1997). Cold season cereals wheat, barley, oat, rye. Tehran University Publications.
4. Allan, R.P., & Soden, B.J. (2008). Atmospheric warming and the amplification of precipitation extremes. Science, 321(5895), 1481–1484. https://doi.org/10.1126/science.1160787
5. Choi, G., Collins, D., Ren, G., Trewin, B., Baldi, M., Fukuda, Y., Afzaal, M., Pianmana, T., Gomboluudev, P., Huong, P.T.T., Lias, N., Kwon, W-.T., Boo, K-.O., Cha, Y-.M., & Zhou, Y. (2009). Changes in means and extreme events of temperature and precipitation in the Asia-Pacific Network region, 1955-2007. International Journal of Climatology, 29(13), 1906–1925. https://doi.org/10.1002/joc.1979
6. Cui, D., Wang, C., & Santisirisomboon, J. (2019). Characteristics of extreme precipitation over eastern Asia and its possible connections with Asian summer monsoon activity. International Journal of Climatology, 39(2), 711–723. https://doi.org/10.1002/joc.5837
7. Dollan, I.J., Maggioni, V., & Johnston, J. (2022). Investigating temporal and spatial precipitation patterns in the Southern Mid-Atlantic United States. Frontiers in Climate, 3. https://doi.org/10.3389/fclim.2021.799055
8. Ebodé, V.B. (2022). Analysis of the spatio-temporal rainfall variability in Cameroon over the period 1950 to 2019. Atmosphere, 13(11), 1769. https://doi.org/10.3390/atmos13111769
9. Fatichi, S., & Caporali, E. (2009). A comprehensive analysis of changes in precipitation regime in Tuscany. International Journal of Climatology: A Journal of the Royal Meteorological Society, 29(13), 1883-1893. https://doi.org/10.1002/joc.1921
10. Halabian, A., & Ghasemi Siani, A. (2021). Analysis of the spatial and temporal trend in precipitation on Caspian basin using GPCC data. Watershed Engineering and Management, 13(2), 283-294. http://doi.org/10.22092/ijwmse.2020.125399.1610
11. Han, H., Hou, J., Jiang, R., Gong, J., Bai, G., Kang, Y., Qi, W., Li, Y., & Li, B. (2021). Spatial and temporal variation of precipitation characteristics in the semiarid region of Xi’an, northwest China. Journal of Water and Climate Change, 12(6), 2697–2715. https://doi.org/10.2166/wcc.2021.048
12. Kendall, M.G. (1975). Rank Correlation Methods, Charles Griffin: London, UK.
13. Ling, M., Han, H., Wei, X., & Lv, C. (2021). Temporal and spatial distributions of precipitation on the Huang-Huai-Hai Plain during 1960–2019, China. Journal of Water and Climate Change, 12(6), 2232–2244. https://doi.org/10.2166/wcc.2021.313
14. Mann, H.B. (1945). Nonparametric tests against trend, Econometrica, 13, 245-259.
15. Mir Mosavi, H., Doustkamian, M., & Setode, F. (2016). Analyzing spatial autocorrelation patterns of heavy and super heavy showers of Iran. Geography and Environmental Planning, 27(3), 67-86. http://doi.org/10.22108/gep.2017.97958
16. Papalexiou, S.M., &Montanari, A. (2019). Global and regional increase of precipitation extremes under global warming. Water Resources Research, 55, 4901–4914. https://doi.org/10.1029/2018WR024067
17. Panahi, A., Hosseini, S. M., Khoramabadi, F., & Ghavibonyad, F. (2021). The study of spatial-temporal changes in the trend of autumn precipitation in Northwest Iran. Climate Change Research, 2(8), 67-82. http://doi.org/10.30488/ccr.2021.320407.1066
18. Peng, Y., Zhao, X., Wu, D., Tang, B., Xu, P., Du, X., & Wang, H. (2018). Spatiotemporal variability in extreme precipitation in China from observations and projections. Water, 10(8), 1089. https://doi.org/10.3390/w10081089
19. Rasooli, A. A., Roshani, R., & Ghasemi, A. R. (2013). Analyzing the spatial-temporal changes of annual precipitation of Iran. Geographical Researches, 28(1), 205-224.
20. Shiu, C.-J., Liu, S. C., Fu, C., Dai, A., & Sun, A. (2012). How much do precipitation extremes change in a warming climate? Geophysical Research Letters, 39(17), L17707. https://doi.org/10.1029/2012GL052762
21. Tang, B., Hu, W., & Duan, A. (2021). Future projection of extreme precipitation indices over the Indochina Peninsula and South China in CMIP6 models. Journal of Climate, 34(21), 8793-8811. https://doi.org/10.1175/JCLI-D-20-0946.1
22. Wang, Y., Ding, Y.Y., & Miao, Q.L. (2012). Spatial and temporal variations of extreme precipitation events in Northeast China. Advanced Materials Research, 573–574, 395–399. https://doi.org/10.4028/www.scientific.net/amr.573-574.395
23. Wu, C., Huang, G., Yu, H., Chen, Z., & Ma, J. (2013). Spatial and temporal distributions of trends in climate extremes of the Feilaixia catchment in the upstream area of the Beijiang River Basin, South China. International Journal of Climatology, 34, 3161–3178. https://doi.org/10.1002/joc.3900
24. Zhai, P., Zhang, X., Wan, H., & Pan, X. (2005). Trends in total precipitation and frequency of daily precipitation extremes over China. Journal of Climate, 18(7), 1096-1108. https://doi.org/10.1175/JCLI-3318.1
25. Zhang, K., Pan, S., Cao, L., Wang, Y., Zhao, Y., & Zhang, W. (2014). Spatial distribution and temporal trends in precipitation extremes over the Hengduan Mountains region, China, from 1961 to 2012. Quaternary International, 349, 346–356. https://doi.org/https://doi.org/10.1016/j.quaint.2014.04.050
26. Zhang, X., Alexander, L., Hegerl, G.C., Jones, P., Tank, A.K., Peterson, T.C., Trewin, B., & Zwiers, F.W. (2011). Indices for monitoring changes in extremes based on daily temperature and precipitation data. Wiley Interdisciplinary Reviews: Climate Change, 2(6), 851–870. https://doi.org/10.1002/wcc.147
27. Zhang, X., Zhang, J., Zhang, X., Yang, M., Pan, X., Liu, C., & Yang, S. (2021). Study on Precipitation Evolution Characteristics in Tongzhou District of Beijing in Recent 65 Years. https://doi.org/10.3233/ATDE210206