不同ET0计算方法在川中丘陵地区的比较及改进

为了获取川中丘陵地区参考作物蒸散量(ET0)在气象资料短缺条件下不同类型的简化计算方法,选用FAO-56Penman-Monteith(PM)法、Hargreaves法、Hargreaves校正法、Priestley-Taylor法和Irmark-Alleen拟合法计算简阳站1999-2005年逐日的ET0。以PM公式为标准,对其他4种方法进行评价及改进。结果表明,Hargreaves校正法计算误差最小,Irmark-Alleen拟合法和Hargreaves法次之,Priestley-Taylor法计算误差最大。通过灵敏度分析,得出川中丘陵地区影响ET0的主要气象因子是相对湿度,因此该文对在湿润气候条件下应用的Priestley-Taylor法和Irmark-Alleen拟合法的参数进行逐月修正,改进后的计算方法精度得到明显提高。Hargreaves校正法、该文提出的Priestley-Taylor修正法和Irmark-Alleen拟合改进法可以作为川中丘陵地区气象资料短缺条件下ET0的简化计算方法。

Comparison and improvement of different calculation methods for ET0 in hilly area of central Sichuan Basin

In order to obtain simplified calculation methods of ET0 in the conditions of lacking meteorological data in hilly area of central Sichuan Basin, the daily ET0 in Jianyang station from 1999 to 2005 was calculated by FAO-56 Penman-Monteith method, Hargreaves method, Hargreaves correction method, Priestley-Taylor method and Irmark-Alleen fitting method. ET0 calculated by PM method was used as the standard, Hargreaves correction method and Priestley-Taylor method had the minimum error, followed by Irmark-Alleen fitting method and Hargreaves method. Through the sensitivity analysis, the main meteorological factor affecting ET0 was relative humidity in hilly area of central Sichuan Basin. Therefore, the parameters of Irmark-Alleen fitting method used in humid climate were corrected month by month in the paper, and the calculation precision was improved obviously after correcting. Hargreaves correction method, Priestley-Taylor method and Irmark-Alleen fitting change method would be used for the calculation of ET0 in the conditions of lacking meteorological data in hilly area of central Sichuan Basin.