Comparative Study on Calculation Methods for Reference Crop Evapotranspiration in Hill and Gully Area of the Loess Plateau
Abstract：Ten kinds of ET0 methods were compared based on the daily meteorological data during the years of 2000 to 2005 from Mizhi stations in hill and gully area of the Loess Plateau.The Penman-Monteith equation standardized by the Food and Agriculture Organization（FAO56-PM） was used to compare with other methods at daily,monthly and yearly scale.The results of linear regression,root mean squared error（RMSE） and mean bias error（MBE） showed that the correlation coefficients between Hargreaves,Turc and FAO56-PM were lower than 0.9,and the other methods were higher than 0.9 at daily scale.The RMSE between FAO56-PM and other methods were 0.35～1.78.Most methods had the high accuracy during winter（November,December and January） and spring（February,March and April）,however,the low accuracy during May to October.The annual ET0 estimated by Priestley-Taylor,FAO24-BC and Penman model were closed to FAO56-PM.The FAO24-Rad,Makkink,Hargreave and Turc equations with fewer parameters should be regulated by the meteorological elements in given local stations.
Keywords：reference crop evapotranspirationcomparative studycalculation methodshill and gully area of the Loess PlateauPenman-Montieth equation
Publication Date：2011-01-01
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)