不同时间步长的Hargreaves公式修正式适用性研究

Applicability on verified equations of Hargreaves at different time steps

为比较不同时间步长的Hargreaves公式修正式的适用性,利用哈尔滨市气象台48年的逐日气象数据,应用Penman-Monteith公式和Hargreaves公式计算了哈尔滨市参考作物蒸发蒸腾量(ET0)的日、旬、月值,基于两公式计算的ET0数据,采纳FAO推荐的方法建立了Hargreaves公式修正式模型,通过分析模型的判定系数及计算结果探讨不同时间步长Hargreaves公式修正式的适用性。结果表明,利用历年逐日、逐旬、逐月ET0值建立的Hargreaves公式修正式计算精度不是很高,而利用ET0多年平均值建立的Hargreaves公式修正式计算精度相对较高,但在同一时间步长或不同时间步长之间,不宜互换应用Hargreaves公式修正式。

Compare several verified Hargreaves equations and their applicability at different time steps,the daily,ten-day and monthly values of reference crop evapotranspiration（ET0） were calculated with Penman-monteith equation and Hargreaves equation,based on 48-year daily meteorological data of Harbin.Hargreaves equations were verified with FAO methodologies using ET0 values calculated from the two equations,and their applicability was analyzed according to the coefficients of determination and calculated results of the verified equations of Hargreaves.The research results showed that verified with the values of daily,ten-day and monthly ET0,the calculating accuracy of Hargreaves equation was not high,while the calculating accuracy of Hargreaves equations was high,verified with the values of daily,ten-day and monthly average ET0,and it was unfavorable to replace these verified Hargreaves equations at the same time steps or among different time steps.