参考作物蒸发蒸腾量计算方法在海河流域的适用性

Comparison of methods for calculating reference crop evapotranspiration in Haihe River basin of China

参考作物蒸发蒸腾量(ET0)的计算公式很多,各公式所需参数各异,为寻找一种所需资料少而又精度较高的替代方法,选用1998年FAO-56分册推荐的Penman-Monteith(PM)、Hargreaves、Irmark-Allen等6种方法分别计算海河流域10个典型气象站30a的参考作物蒸发蒸腾量,并以PM公式为标准,对其他方法进行评价。结果表明,10个站点中除了五台山地区,Hargreaves与FAO-24Radiation这2种方法更接近于PM方法的计算结果,其误差较小,在海河流域缺少辐射和风速资料的站点,可以利用Hargreaves方法来代替PM方法;在五台山地区,可以考虑在Hargreaves基础上对其参数进行适当调整。

There are a lot of estimation methods for reference crop evapotranspiration（ET0） ,however,different parameters are required. Therefore,it is particularly important to find accurate alternative methods. Based on the data of ten weather stations in Haihe River basin for 30 years,ET0 was estimated with six methods,such as FAO-56 Penman-Monteith（PM） ,Hargreaves and Irmark-Allen etc. taking PM equation as the standard,the other methods were evaluated. The results showed that for stations except Wutaishan station in Haihe River basin,the estimated ET0 by the Hargreaves and the FAO-24 Radiation equations were closer to the values of ET0 estimated by the PM method than. by other methods. Therefore,it is concluded that Hargreaves methods can replace the PM method at these stations which are short of radiation and wind speed data;whereas,in Wutaishan Mountain area,the empirical parameters of the Hargreaves equations should be changed before being used in given local stations.