宁夏荒漠草原区参考作物蒸散量估算方法比较

Comparison of Many Equations for Calculating Reference Corp Evapotranspiration in Hungriness Grassland Areas of Ningxia

利用宁夏荒漠草原区银川和盐池2007—2010年逐日气象资料,以FAO56Penman-Montieth(PM)方程计算结果为标准,根据决定系数(R2)、均方根误差(RMSE)、平均偏差(MBE)和一致性指数(IOA),在日、月和年的不同时间尺度上分析评价8种ET0估算模型。结果表明,Kimberly、Penman模型计算的日ET0与PM模型的R2大于0.970,IOA高于0.980,二者计算的ET0与PM模型最为接近。大部分方法估算精度在冬春季(11月—次年4月)高,而在5—10月则较低。Kimberly、Penman模型估算的年ET0与PM模型计算值最为接近。对于PriestlyTaylor、Makkink和Hargreave等参数较少的模型,在使用时应利用气象数据进行系数校正。

Reference crop evapotranspiration（ET0）was estimated based on the daily meteorological data of Yinchuan and Yanchi in hungriness grassland areas of Ningxia over 2007—2010.The FAO 56PenmanMonteith（PM）equation was used as standard to analyze and evaluate eight different ET0 methods by determination coefficient（R2）,root mean squared error（RMSE）,mean bias error（MBE）and index of agreement（IOA）at daily,monthly and yearly dimensions.The results showed that R2 between Kimberly and Penman equations and PM equation were more than 0.97,and IOA were higher than 0.98 at daily dimension.The ET0 values estimated by Kimberly and Penman equations were closer to ET0 calculated by PM equations compared to the other equations.Most of the eight methods were more accurate from November to April while they were less accurate from May to October.The annual ET0 estimated by Kimberly and Penman models was closer to PM model.The parameters of Priestly-Taylor,Makkink and Hargreave equations should be adjusted by the local meteorological factors to get the fitted effectiveness.