تعیین مناسب‌ترین شاخص برای خشکسالی‌های مناطق بارشیِ ایران

نوع مقاله : مقاله پژوهشی

نویسندگان

1 دانشجوی دکتری جغرافیا و اقلیم‌شناسی، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران

2 استادیار گروه جغرافیای طبیعی، دانشگاه خوارزمی، تهران، ایران

3 استاد گروه جغرافیا، واحد علوم و تحقیقات، دانشگاه آزاد اسلامی، تهران، ایران

چکیده

خشکسالی­ها از جمله مهم­ترین بلایای طبیعی هستند که به سه شکل اقلیمی، هیدرولوژی و کشاورزی دیده می­شوند. با توجه به واقع شدن کشور ایران در قلمرو آب و هواهای خشک جهان و در نتیجه حساسیت زیاد کشور به این مسئله، ضرورت مطالعه و بررسی پیرامون مسائل مربوط به خشکسالی مهم­تر و بیشتر جلوه می­نماید. در همین راستا تحقیق حاضر خشکسالی اقلیمی را مد نظر قرار داده و کاربرد شاخص­های معتبر خشکسالی را بر روی مناطق مختلف کشور ارزیابی نموده است. بدین منظور کل پهنه ایران را به صورت مناطق شش گانه بارشی در نظر گرفته و از بین تمامی ایستگاه­های موجود که دارای آمار هواشناسی کامل­تر و معتبرتری نسبت به بقیه ایستگاه­ها بودند، انتخاب شدند. سپس از بین شاخص­های خشکسالی اقلیمی شش شاخص RAI,SIAP,PNPI,DI,Z و SPI را برگزیده و خشکسالی هر کدام از مناطق مختلف بارشی به وسیله این شاخص­ها تعیین گردید و نتایج را با ضریب همبستگی اسپیرمن بین بارندگی و رتبه شاخص­ها با یکدیگر مقایسه نموده و مشخص شد که کدام شاخص برای چه منطقه بارشی بهتر عمل می­کند؛ نهایتاً معلوم گردید که شاخص DI با دارا بودن بالاترین ضریب همبستگی اسپیرمن مناسب­ترین شاخص برای کل پهنه جغرافیایی ایران است.

کلیدواژه‌ها


عنوان مقاله [English]

Determining the most suitable index for droughts rainfall region in Iran

نویسندگان [English]

  • A Vakhshoori 1
  • Z Jafar Poor 2
  • P Kardavani 3
چکیده [English]

       Droughts are the most important natural disasters. Droughts exist in 3 forms Climate, Hydrology and Agriculture. Due to the location of Iran in the realm of global dry climates and high sensitivity to this issue in country, it is necessary to study and investigate about the problems related to droughts. For this purpose, this presented research is considered the climate drought and evaluated the valid indicators of drought on the various regions of country. In this order, the whole area of Iran considered as six regions of rainfall and among all existing stations, the stations which have the more perfect and valid statistics of aerology rather than others were selected. Then among the climate drought indicators, six indicators Z, DI, PNPI, SIAP, RAI and SPI were selected and the drought of each various regions of rainfall were defined through these indicators and results was compared using Spearman's correlation coefficient between rainfall and indicators ranking and it was found that the best indicator for each region of rainfall; Finally it was found that the DI indicator has the highest Spearman's correlation coefficient and it will be the most appropriate indicator for whole area of Iran.

کلیدواژه‌ها [English]

  • rainfall region
  • Climate drought
  • Indicators of climate drought
  • Spearman's correlation coefficient
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