西安地区Priestley—Taylor和Hargreaves方法应用比较

Comparison with the application of Priestley-Taylor and Hargreaves methods in Xi'an

以世界粮农组织推荐的Penman-Monteith方法作为计算参考作物蒸发蒸腾量的标准,对Priestley-Taylor和Hargreaves方法在西安地区的适用性问题进行了探讨,分别建立了这两个公式的回归关系式,并且对这两种方法进行修正。结果表明:Hargreaves方法在西安地区有着较好的准确度,相对误差较小。而Priestley—Taylor方法得到的结果虽然与Penman—Monteith方法计算结果呈相同的变化趋势,相关系数R2=0.94,但计算值有较大的差异;经过修正后相对误差明显减小。因此,在气象资料有限的条件下,可以直接用Hargreaves方法来计算参考作物蒸发蒸腾量;而Priestley-Taylor方法必须经过修正后才能使用。

The paper has taken the Penman--Monteith formula nominated by the Food and Agricultural of theUnited Nations as a criteria to calculate the reference crop evapotranspiration, discussed the applicabity of two methods as Priestley--Taylor and Hargreaves and modified these founding these two methods by set up regressive relations. The results have shown the Hargreaves method had a preferable veracity in Xi＇an, and the relative error was a less. While the Priestley--Taylor method had the same trend with the Penman--Monteith formular, and the correlativity was 0.94, but the different was not negligible. After modified, the relative error was minimized clearly. So under the limited weather data condition, the Hargreaves method can be directly calculated the reference crop evapotranspiration. And Priestley-Taylor method must be modified then can be calculated the reference crop evapotranspiration.