عدم قطعیت مقادیر شدت-فراوانی بارش‌های حداکثر در اثر تغییر اقلیم آتی (مطالعه موردی: استان خراسان رضوی)

نوع مقاله: مقاله پژوهشی

نویسنده

استادیار/ دانشکده مهندسی عمران، دانشگاه صنعتی جندی شاپور

چکیده

گرمایش جهانی خصوصیات بارش‌های حدی را دستخوش تغییراتی خارج از دامنه تغییرات درونی اقلیم کرده است. در این تحقیق تحلیلی از نحوه تغییر مقادیر شدت-مدت-فراوانی بارش(IDF) تحت 10 سناریوی اقلیمی مشتق شده از مدل‌های اقلیم جهانی و سناریوی انتشار A1B برای دوره 2040- 2021 در استان خراسان رضوی ارائه شده است. مقادیر IDF برای 23 ایستگاه مورد بررسی تحت سناریوهای اقلیمی آینده در 3 سطح ریسک (25%، 50% و 75%) توسط یک روش ترکیبی پیشنهادی شامل: (1) تصویر سازی سناریوی بارش روزانه آتی توسط یک مدل ریزمقیاس نمایی ناپارامتریک توسعه داده شده برای مناطق خشک و نیمه خشک، (2) استخراج مقادیر IDF براساس روابط چندک-فراوانی بارش بین بارش‌های ساعتی و روزانه در ترم سری‌های حداکثر سالانه، برآورد شده‌اند. نتایج نشان می‌دهد که شدت بارش‌ها در سطح ریسک 50% نسبت به دوره پایه 2012-1993 بین 23-% تا 3/7% تغییر خواهد کرد. در این بین تداوم‌های کمتر نسبت به بیشتر دامنه تغییرات مثبت تری داشته و در دوره‌‌های بازگشت بالاتر دامنه تغییرات وسیعتر خواهد بود. بطور کلی مناطق مرکزی و جنوبی افزایش کمتری را نسبت به نواحی شمالی استان شاهد خواهند بود. همچنین مناطق پرباران شدت سیل خیزی بیشتری را پیش رو خواهند داشت؛ و در مقابل مناطق کم باران کاهش شدیدتری را متحمل می‌شوند. درسطوح ریسک کم نیز مقادیر شدت‌های حداکثر در آینده افزایش خواهد یافت؛ که این موضوع باید در طراحی سازه‌های پراهمیت مورد توجه خاص قرار گیرد.

کلیدواژه‌ها

موضوعات


عنوان مقاله [English]

Uncertainty of extreme rainfall intensity and frequency under future climate change impact: Khorasan-Razavi province

نویسنده [English]

  • H. Seyed Kaboli
Assistant Professor, Department of Civil Engineering, Jundi Shapur University of Technology, Dezful, Iran
چکیده [English]

Global Warning has caused the characteristics of extreme rainfall changed out of range of the internal variability of climate. In this research, an analysis is presented from how variation in intensity, Duration-and Frequency (IDF) of rainfall under 10 climate scenarios derived climate models and A1B emission scenario for 2021-2040 periods in Khorasan-Razavi province. The IDF values for 23 raingage have projected under future climate scenarios in 3 risk levels (25%, 50% and 75%) by a proposed combined approach include: (1) Develop a nonparametric downscaling model to projection of future daily rainfall in arid and semi-arid regions, (2) Establishing frequency-quantile relationships between the t-hour and daily rainfall based annual maximum for estimating the IDF values. Under risk level 2, the results show a wide range of between -23% to +7.3% in rainfall intensity than baseline (1993-2012). The short-duration rainfalls change in more positive range then long-durations; and for return periods of more than 10-year, the range of changes will be wide in this area. Generally, central and southern regions will be received slight increase than northern regions. Also, the high rainfall regions will be ahead a more severe flooding, while the low rainfall regions will be suffered a more severe decrease. Also, in low risk level, rainfall intensity will be increased in the future period; it can be warning to design hydraulic infrastructures with high emphasis.

کلیدواژه‌ها [English]

  • Climate change
  • Extreme rainfall
  • Khorasan-Razavi
  • Uncertainty
  • Downscaling

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