temperature- and radiation based methods against the standard fao penman- monteith for estimating the reference evapotranspiration (et0) in gorgan

نویسندگان

پدرام عطارد

دانشیار گروه جنگل داری و اقتصاد جنگل، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران سید محمد معین صادقی

دانشجوی دکتری جنگل‏شناسی و اکولوژی جنگل، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران امید فتحی زاده

دانشجوی دکتری جنگل داری، دانشکدة منابع طبیعی و علوم دریایی، دانشگاه تربیت مدرس، نور، مازندران مریم السادات مطهری

کارشناس ارشد جنگل‏شناسی و اکولوژی جنگل، دانشکدة منابع طبیعی، دانشگاه تهران، کرج، ایران سعید راهبری سی سخت

چکیده

the fao penman - monteith (f-p-m) method is now broadly accepted as the standard for estimating the reference evapotranspiration (et0). the method is also now used for evaluating the temperature-based [blaney-criddle (b-c) and hargreaves-samani (h-s)] and radiation-based [jensen-haise (j-h) and turc (tc)] methods. the objective was to compare the et0 estimated by the b-c, h-s, j-h, tc methods with that estimated by the f-p-m method in a semiarid climate using the meteorological data recorded in hashem-abad agro-meteorological station, gorgan. the mean value of et0 was 3.13 mm.day-1 using the f-p-m method. at daily scale, tc method showed the lowest rmse (root mean square error), 0.98 mm.day-1. at monthly scale, in compare to the other methods, the rmse values by tc method were lower in april as well as from september to march, averaged 0.06 mm.day-1 with the percentage error of 3%. during the summer season, july and august, however, b-c method suggested the lowest rmse value than those of the others (rmse 0.32 mm.day-1 with the percentage error of 6%). the h-s method behaves the best for monthly estimation (rmse 0.42 mm.day-1, the percentage error of 7%) during may to june. the f-p-m method for estimating et0 requires data often not recording in the meteorological stations; hence et0 should be estimated using the proposed simpler methods in compare to the f-p-m. the adaptation of the methods to different climates should be essentially tested by the standard f-p-m method.

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عنوان ژورنال:

جنگل و فرآورده های چوب

جلد ۶۸، شماره ۲، صفحات ۳۵۹-۳۶۹

کلمات کلیدی

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