پیش‌نگری رخداد فرین‌های ترکیبی گرم-خشک (CDHE) در ایران

نوع مقاله : مقاله پژوهشی

نویسنده

گروه جغرافیا، دانشکده ادبیات و علوم انسانى دکتر على شریعتى، دانشگاه فردوسی مشهد، مشهد، ایران.

چکیده

رخدادهای فرین ترکیبی، به‌ویژه همزمانی گرما و خشکی، تهدیدی فزاینده برای جوامع و اکوسیستم‌های مناطق آسیب‌پذیر محسوب می‌شوند. این مطالعه با هدف ارزیابی و پیش‌نگری تغییرات فراوانی و طول دوره فرین ترکیبی گرم-خشک (CDHE) در ایران انجام شد. در این تحقیق، از شش مدل مشارکت‌یافته در CMIP6 استفاده شد. به‌منظور کاهش عدم‌قطعیت‌های مدل‌های منفرد و افزایش کارایی پیش‌نگری‌ها، از رویکرد همادی چندمدلی وزنی (WMME) مبتنی‌بر روش نمره مهارت وردایی بین‌سالی (IVS) استفاده شد. تحلیل‌ها بر اساس مقایسه دوره تاریخی (2014-1990) با دوره‌های آینده نزدیک تا دور، تحت دو سناریوی SSP2-4.5 و SSP5-8.5 انجام شد. یافته‌های دوره تاریخی نشان‌دهنده روند افزایشی و آماری معنادار در فراوانی (53/0 رخداد/دهه) و طول دوره (86/0 روز/دهه) رخدادهای CDHE است. پیش‌نگری‌ها نشان‌دهنده بی‎هنجاری افزایشی رخداد CDHE در سراسر کشور است. تحت سناریوی SSP2-4.5، فراوانی سالانه این رخدادها از متوسط 8/2 رخداد در دوره تاریخی به 2/8 رخداد تا پایان قرن افزایش می‌یابد. تحت سناریوی SSP5-8.5، این افزایش به مراتب شدیدتر بوده و فراوانی رخدادها تا 4/10 رخداد افزایش خواهد یافت. همچنین، طول دوره نیز افزایش قابل‌توجهی را تجربه خواهد کرد. به‌طوری‌که از متوسط پهنه‌ای 4/4 روز در دوره تاریخی به 6/20 روز تحت سناریو SSP2-4.5 و 36 روز تحت سناریو SSP5-8.5 خواهد رسید. نتایج به‌روشنی بر تشدید قابل‌توجه ریسک مخاطرات مرتبط با رخداد فرین‌های ترکیبی گرم-خشک در ایران طی قرن بیست‌ویکم تأکید دارد. این یافته‌ها ضرورت اتخاذ فوری استراتژی‌های سازگاری در برابر چالش‌های اقلیمی فزاینده را برجسته می‌سازد.

کلیدواژه‌ها

موضوعات

عنوان مقاله [English]

Projecting Future Compound Dry and Hot Extremes Events (CDHE) in Iran

نویسنده [English]

  • Abbas Ali Dadashi-Roudbari
Department of Geography, Faculty of Dr. Ali Shariati Letters and Humanities, Ferdowsi University of Mashhad, Mashhad, Iran.
چکیده [English]

Climate change has amplified the frequency of weather and climate extreme events, such as heatwaves, heavy precipitation, and droughts. These extreme events are increasingly likely to co-occur, resulting in what are known as Compound Extreme Events. Given its geographical location within the global arid and semi-arid belt and the inherent vulnerability of its ecosystems, Iran is recognized as a critical hotspot for the impacts of climate change. A growing body of scientific evidence indicates that the nation is increasingly affected by such compound events. Compound extremes, particularly the concurrence of heatwaves and drought, pose a significant and escalating threat to societies and ecosystems in vulnerable regions. This study aims to assess and project changes in the frequency and duration of Compound Dry-Hot Extremes (CDHE) across Iran. The data utilized in this research are twofold: observational data from synoptic weather stations and outputs from CMIP6 models. The observational dataset comprises daily maximum temperature and precipitation time series from 98 synoptic stations across the country for the 1990–2014 period. For future projections, this study employed six models from the CMIP6 ensemble. To mitigate the uncertainties inherent in individual models and enhance predictive performance, a Weighted Multi-Model Ensemble (WMME) approach was adopted, based on the Inter-annual Variability Skill (IVS) score method. The analysis involves comparison of a historical period (1990–2014) with near-future (2026–2050), mid-future (2051–2075), and far-future (2076–2100) periods under two shared socio-economic pathways (SSP): SSP2-4.5 and SSP5-8.5. The specific phenomenon investigated is the compound hot-dry event. A CDHE is identified by the simultaneous occurrence of two individual extremes, each defined by specific percentile thresholds. A hot event is defined as a day when the maximum temperature exceeds the 95th percentile of daily values for a given period. Concurrently, a dry event is characterized by daily precipitation falling below the 5th percentile for the same period. Analysis of the historical period reveals a statistically significant increasing trend in both the frequency (0.53 events/decade) and duration (0.86 days/decade) of CDHEs. Future projections indicate a positive anomaly, signifying an increase in CDHE occurrences. Under the SSP2-4.5 scenario, the annual frequency of these events is projected to rise from a historical average of 2.8 events to 8.2 events annually by the end of the century. The increase is substantially more severe under the SSP5-8.5 scenario, with the frequency escalating to 10.4 events per year. Similarly, the duration of these events is expected to lengthen considerably, increasing from a spatially averaged 4.4 days in the historical period to 20.6 days under SSP2-4.5 and a notable 36 days under SSP5-8.5. These results unequivocally highlight a significant intensification of risks associated with compound hot-dry extremes in Iran throughout the 21st century. These findings underscore the urgent necessity for implementing proactive adaptation strategies to address the escalating climate challenges.

کلیدواژه‌ها [English]

  • Compound Dry-Hot Extremes
  • Dry-Hot Extremes
  • climate change
  • CMIP6
  • Iran

مراجع

اسدی رحیم‌ بیگی، ن.؛ زرین، آ.؛ مفیدی، ع. و داداشی رودباری، ع. ع. (1402). پیش‌بینی فرین‌های بارشی ایران در آینده نزدیک (2028-2021) با استفاده از پروژه پیش‌بینی اقلیمی دهه‌ای (CMIP6-DCPP). مجله فیزیک زمین و فضا، 49(3)، 707-725.
خان سالاری، س. و محمدی، س. ع. (1402). پیش‌نگری بارش‌های فرین در ایران بر اساس رویکرد همادی مدل‌های CMIP6 در آینده نزدیک (2050-2026) با وزن‌دهی مبتنی‌بر رتبه. مجله فیزیک زمین و فضا، 49(3)، 727-746.
زرین، آ. و داداشی رودباری، ع. ع. (1400الف). پیش‌نگری دوره‌های خشک و مرطوب متوالی در ایران مبتنی‌بر برونداد همادی مدل‌های تصحیح شده اریبی CMIP6. مجله فیزیک زمین و فضا، 47(3)، 561-578.
زرین، آ. و داداشی رودباری، ع. ع. (1400ب). مدیریت ریسک خشکسالی در شرایط تغییر اقلیم: نقش سیاست‌های ملی و برنامه مدیریت خشکسالی (DMP). فصلنامه آب و توسعه پایدار، 8(1)، 107-112.
Adeyeri, O. E., Zhou, W., Ndehedehe, C. E., & Wang, X. (2024). Global vegetation, moisture, thermal and climate interactions intensify compound extreme events. Science of the Total Environment, 912, 169261.
Alizadeh-Choobari, O., & Najafi, M. S. (2018). Extreme weather events in Iran under a changing climate. Climate dynamics, 50(1), 249-260.
Asadi-RahimBeygi, N., Zarrin, A., Mofidi, A., & Dadashi-Roudbari, A. (2024). Near-term temperature extremes in Iran using the decadal climate prediction project (DCPP). Stochastic environmental research and risk assessment, 38(2), 447-466.
Chen, W., Jiang, Z., & Li, L. (2011). Probabilistic projections of climate change over China under the SRES A1B scenario using 28 AOGCMs. Journal of Climate, 24(17), 4741-4756.
Clima, T., & Te, W. (2023). Guidelines on the Definition and Characterization of Extreme Weather and Climate Events. World Meteorological Organization, Geneva, Switzerland.
Cutter, S. L. (2018). Compound, cascading, or complex disasters: what's in a name?. Environment: science and policy for sustainable development, 60(6), 16-25.
Ehret, U., Zehe, E., Wulfmeyer, V., Warrach-Sagi, K., & Liebert, J. H. E. S. S. (2012). HESS Opinions" Should we apply bias correction to global and regional climate model data?". Hydrology and Earth System Sciences, 16(9), 3391-3404.
Fang, P., Wang, T., Yang, D., Tang, L., & Yang, Y. (2025). Substantial increases in compound climate extremes and associated socio-economic exposure across China under future climate change. NPJ Climate and Atmospheric Science, 8(1), 17.
IPCC. (2021). Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change [Masson-Delmotte, V., P. Zhai, A. Pirani, S.L. Connors, C. Péan, S. Berger, N. Caud, Y. Chen, L. Goldfarb, M.I. Gomis, M. Huang, K. Leitzell, E. Lonnoy, J.B.R. Matthews, T.K. Maycock, T. Waterfield, O. Yelekçi, R. Yu, and B. Zhou (eds.)]. Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA, 2391 pp., doi:10.1017/9781009157896.
Jahanshahi, A., Booij, M. J., Patil, S. D., & Gupta, H. (2024). An ensemble-based projection of future hydro-climatic extremes in Iran. Journal of Hydrology, 642, 131892.
Jangi, M. R., Zarrin, A., Mofidi, A., & Dadashi-Roudbari, A. (2024). Intensifying heatwave trends in Iran based on observational data using excess heat factor (EHF). Natural Hazards, 120(2), 2073-2090.
Jiang, Z., Li, W., Xu, J., & Li, L. (2015). Extreme precipitation indices over China in CMIP5 models. Part I: Model evaluation. Journal of Climate, 28(21), 8603-8619.
Knutti, R., Rugenstein, M. A., & Hegerl, G. C. (2017). Beyond equilibrium climate sensitivity. Nature Geoscience, 10(10), 727-736.
Krishnan, R., Dhara, C., Horinouchi, T., Gotangco Gonzales, C. K., Dimri, A. P., Singh Shrestha, M., Swapna, P., Roxy, M. K., Son, S.-W., Ayantika, D. C., Cruz, F. A. T., & Qiao, F. (2025). Compound weather and climate extremes in the Asian region: science-informed recommendations for policy. Frontiers in Climate, 6, 1504475.
Liu, W., Sun, F., Feng, Y., Li, C., Chen, J., Sang, Y. F., & Zhang, Q. (2021). Increasing population exposure to global warm-season concurrent dry and hot extremes under different warming levels. Environmental Research Letters, 16(9), 094002.
Liu, Z., Jiao, L., & Lian, X. (2025). Changes in compound extreme events and their impacts on cropland productivity in China, 1985–2019. Earth's Future, 13(3), e2024EF005038.
Maraun, D., Shepherd, T. G., Widmann, M., Zappa, G., Walton, D., Gutiérrez, J. M., Hagemann, S., Richter, I., Soares, P. M. M., Hall, A., & Mearns, L. O. (2017). Towards process-informed bias correction of climate change simulations. Nature Climate Change, 7(11), 764-773.
Messori, G., Bevacqua, E., Caballero, R., Coumou, D., De Luca, P., Faranda, D., Kornhuber, K., Martius, O., Pons, F., Raymond, C., Ye, K., Yiou, P., & Zscheischler, J. (2021). Compound climate events and extremes in the midlatitudes: Dynamics, simulation, and statistical characterization. Bulletin of the American Meteorological Society, 102(4), E774-E781.
Ridder, N. N., Ukkola, A. M., Pitman, A. J., & Perkins-Kirkpatrick, S. E. (2022). Increased occurrence of high impact compound events under climate change. Npj Climate and Atmospheric Science, 5(1), 3.
Safaei, V., Zarrin, A., Mosaedi, A., & Dadashi-Roudbari, A. (2025). Intensifying droughts and their relationship with temperature and precipitation extremes in Iran. Theoretical and Applied Climatology, 156(9), 1-24.
Taylor, K. E. (2001). Summarizing multiple aspects of model performance in a single diagra
United Nations Office for Disaster Risk Reduction (UNDRR)/International Science Council (ISC) (2020). Hazard Definition and Classification Review – Technical Report; UNDRR: Geneva, 2020. https://www.undrr.org/publication/hazard-definition-and-classification-review-technical-report.
United Nations Office for Disaster Risk Reduction (UNDRR)/International Science Council (ISC) (2021). Hazard Information Profiles: Supplement to Hazard Definition and Classification Review – Technical Report; UNDRR: Geneva, 2021. https://www.undrr.org/publication/hazard information-profiles-hips.
Vaghefi, S. A., Keykhai, M., Jahanbakhshi, F., Sheikholeslami, J., Ahmadi, A., Yang, H., & Abbaspour, K. C. (2019). The future of extreme climate in Iran. Scientific reports, 9(1), 1464.
Wu, Y., Miao, C., Sun, Y., AghaKouchak, A., Shen, C., & Fan, X. (2021). Global observations and CMIP6 simulations of compound extremes of monthly temperature and precipitation. GeoHealth, 5(5), e2021GH000390.
Yang, Y., & Tang, J. (2023). Substantial differences in compound long‐duration dry and hot events over China between transient and stabilized warmer worlds at 1.5° C global warming. Earth's Future, 11(3), e2022EF002994.
Yang, Y., & Zhao, N. (2024). Future projections of compound temperature and precipitation extremes and corresponding population exposure over global land. Global and Planetary Change, 236, 104427.
Yu, H., Lu, N., Fu, B., Zhang, L., Wang, M., & Tian, H. (2022). Hotspots, co-occurrence, and shifts of compound and cascading extreme climate events in Eurasian drylands. Environment International, 169, 107509.
Yu, R., Dong, S., Han, Z., & Li, W. (2024). Increased exposure of rice to compound drought and hot extreme events during its growing seasons in China. Ecological Indicators, 167, 112735.
Zarrin, A., Dadashi-Roudbari, A., & Hassani, S. (2022). Future changes in precipitation extremes over Iran: Insight from a CMIP6 bias-corrected multi-model ensemble. Pure and Applied Geophysics, 179(1), 441-464.
Zhang, L., Yuan, F., & He, X. (2024). Probabilistic assessment of global drought recovery and its response to precipitation changes. Geophysical Research Letters, 51(1), e2023GL106067.
Zhang, W., Luo, M., Gao, S., Chen, W., Hari, V., & Khouakhi, A. (2021). Compound hydrometeorological extremes: Drivers, mechanisms and methods. Frontiers in Earth Science, 9, 673495.
فیزیک زمین و فضا
دوره 52، شماره 1
تاریخ انتشار الکترونیکی: 9 خرداد 1405
خرداد 1405
صفحه 161-178

فایل ها

هم رسانی

ارجاع به این مقاله

آمار