潜在蒸散发公式2种修正方法及其在闽江流域的应用研究

Potential Evapotranspiration Equations:Two Modification Methods and Their Application in Minjiang River Basin

各类潜在蒸散发经验估算法具有区域性的特点,实际运用时需要进行修正。常用的修正方法是通过线性回归法对经验公式的计算结果进行修正,并没有将修正反映到经验公式中的系数上。本研究提出一种系数修正的方法,通过逐月误差比例校正来修正经验公式中的参数,称之为误差比例校正法。以FAO推荐的Penman-Monteith法为标准,比较经线性回归法、误差比例校正法2种方法修正前后6种经验估算法(Blaney-Criddle、Hargreaves、Hamon、Makkink、Priestley and Taylor、Rohwer)在闽江流域的计算精度,从而对误差比例校正法的修正效果及稳健性进行探讨。结果表明:逐月误差比例校正法整体上具有较好的修正效果,可以较大程度提高6种经验方法在该区域的计算精度;常用的线性回归法虽计算较误差比例校正法稍复杂,但其修正效果及稳健性略优于误差比例校正法。

As the application of different empirical equations for computing potential evapotranspiration（ET0） has been regionally restricted,modification is needed.A commonly used modification method is to correct the results of empirical equations by liner regression without amending their coefficients.This study is providing a new way to modify the coefficients using monthly relative error correction,namely the relative error modification method.To study the effect and stability of the relative error modification method,six different representative empirical equations,including those of BlaneyCriddle,Hargreaves,Hamon,Makkink,Priestley-Taylor and Rohwer,were compared with PenmanMonteith equation which was set as the standard for testing the effect of applicability and the stability for each equation in Minjiang River Basin.The results showed that 1） performances of the six empirical equations could be significantly improved by the relative error modification method,and 2） the commonly used linear regression method performed a little better than the relative error correcting method though it was a bit more complicated than the relative error modification method.