یاسمن لطفی - دانشجوی کارشناسی ارشد مهندسی منابع آب، گروه مهندسی آب، دانشکده مهندسی آب و خاک، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران
مهدی مفتاح هلقی - دانشیار گروه مهندسی آب، دانشکده مهندسی آب و خاک، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران
خلیل قربانی - دانشیار گروه مهندسی آب، دانشکده مهندسی آب و خاک، دانشگاه علوم کشاورزی و منابع طبیعی گرگان، گرگان، ایران

For projection of possible climate change impacts on agriculture and water resources climate models are used but there exist uncertainties in the outputs of these models. The aim of this study is to project the possible changes of precipitation and uncertainty involved in Hashem- Abad station, north of Iran, using general circulation models. For this purpose, precipitation observations for the baseline period of (۱۹۹۰–۲۰۱۰) were collected. Then the outputs of the ۸ GCM models (including ACCESS۱-۰, CanESM۲, CMCCCMS, GISSE۲H, HadGEM۲CC, MIROC۵, MIROCESM, and IPSLCM۵AMR) under the two scenarios of RCP ۴.۵ and RCP ۸.۵ were downscaled using change factor method and compared. The uncertainties of the GCM models for both emission scenarios were also investigated. Comparison of means of precipitation time series for the period ۲۰۱۰–۲۰۴۰ was performed by t-test. The results indicated a decreasing trend in most of the months. The GISSE۲H model projected the most significant decreasing trend of total monthly precipitation. The highest uncertainty was observed in July for the both scenarios. Besides, although the outputs of the models didn't show a significant difference in ۸۲% of the cases, the models’ uncertainty band indicated a major difference among the results. Further uncertainty analysis may be recommended for more scrutiny.  

تغییر اقلیم, مدل‌های گردش عمومی جو, عدم قطعیت, بارش