不同方法计算ET0及对长时间序列气象因素的响应

ET0 calculated by different methods and its response to long time series meteorological factors

本文以FAO-56 P-M方法计算值为标准,分析比较9种ET0计算方法在南京地区的适用性,在此基础上分析气象要素对ET0年际变化趋势及影响。结果表明:Allen拟合模型计算结果在全年、各季都是最接近P-M模型计算的标准结果,Trajkovic、Ravazzani et al.(2012)、Modified Hargreaves的结果精度在其后。Priestley-Taylor、Romanenko以及Hargreaves Samani方法结果精度都不好,不能代替P-M方法计算ET0。1961—2012年用P-M模型计算的年平均ET00总体趋于上升,导致这种变化的气象因素是大气净辐射Rn,其次是水汽压饱和差VPD,气温影响在2005年后削弱。

Based on FAO-56 P-M method,this paper compares and analyzes the applicability of nine ET0 calculation methods in Nanjing,and on this basis,analyzes the inter annual variation trend and influence of meteorological factors on ET0.The results show that the calculation results of Allen fitting model are the closest to the standard results of P-M model in the whole year and each season,and the results of trajkovic,ravazzani et al.(2012)and modified Hargreaves are lower than those of other methods.Priestley Taylor,romanenko and Hargreaves samani methods have poor accuracy,which can not replace the p-m method to calculate ET0.From 1961 to 2012,the annual average ET0 calculated by P-M model tended to increase.The meteorological factor leading to this change was atmospheric net radiation RN,followed by vapor pressure saturation difference VPD,and the influence of temperature weakened after 2005.