东北丘陵半干旱区参考作物蒸散量计算方法比较

Comparative Study on Calculation Methods of Evapotranspiration of Reference Crop in Hilly Semi-Arid Area

利用FAO Penman-Monteith公式FAO、 Penman修正式和Priestley-Taylor公式对东北丘陵半干旱区观测到的气象数据进行了逐日参考作物蒸散量计算。结果显示,FAO Penman修正式的计算值比FAO Penman-Monteith公式的计算值平均偏大约16%,2种比较方法具有很好的相关性;而Priestley-Taylor公式的计算值与FAO Penman-Monteith公式的计算值相比,差异比较显著,是由于Priestley-Taylor公式没有考虑空气动力项对参考作物蒸散量的影响。因此,在东北丘陵半干旱区使用Priestley-Taylor公式计算参考作物蒸散量,必须根据不同月份对公式中的常数项重新进行修正。

It is important to estimate the reference crop evapotranspiration to accelerate researches on water cycle and transfer in semi-arid area of Northeast China. With detail data from local weather station in an experimental catchment named as Fuxin,the daily was calculated with FAO Penman-Montoith equation,FAO Penman equation and Priestley-Taylor equation,respectively. The results showed that the average calculated value from was FAO Penman 16% higher than that from FAO Penman-Monteith. Failing to consider aerodynamic influence in Priestley-Taylor equation should be the reason resulting in the difference. Therefore, if Priestley-Taylor equation was used to estimate reference crop evapotranspiration in the study area, the parameter in Priestley- Taylor equation should be modified in different months.