Venlo型温室内参考作物蒸散量计算方法比较研究

Comparison of Different Methods for Calculating the Evapotranspiration in Venlo-type Greenhouse

【目的】明确温室内参考作物蒸散量(ET_0)计算方法。【方法】通过实测Venlo型温室内气象数据,并对FAO-56Penman-Monteith(FAO-56 P-M)中隐含的空气动力阻力r*a进行修正,以修正后的Penman-Monteith法作为计算温室内ET_0的标准方法,对其他4种常用的ET_0计算方法:FAO-56 P-M法、FAO-24 Penman法、Irmak-Allen(I-A)法、Priestley-Taylor(P-T)法进行了对比分析。【结果】试验期间温室内日ET_0变化范围为0.49~6.04 mm/d,平均为2.43mm/d;4种计算方法与Penman-Monteith(P-M)修正法均具有良好的线性关系(R2>0.90),FAO-24 Penman法与P-M修正法计算结果最为接近(RMSE=0.40 mm/d,NSE=0.93),其次为I-A法(RMSE=0.67 mm/d,NSE=0.81)、P-T法(RMSE=0.76 mm/d,NSE=0.76),而在大田条件下广泛应用的FAO-56 P-M法表现最差(RMSE=1.18 mm/d,NSE=0.41)。【结论】4种ET_0计算方法中,I-A法应用最简便,可作为气象资料短缺条件下该地区温室ET_0的简化计算方法。

【Objective】Different methods are available for calculating the reference crop evapotranspiration（ET0）,and the purpose of this paper is to compare their applications in irrigated greenhouses.【Method】Experiment was carried out in a Venlo-type greenhouse with the meteorological factors in the house measured. The FAO-56 Penman-Monteith formula was modified using a fixed aerodynamic resistance r＊a. We compared four commonly-used models to calculate the evapotranspiration： the FAO-56 Penman-Monteith, the FAO-24 Penman-Monteith method,the Priestley-Taylor and the Irmak-Allen, with the Penman-Monteith modified（P-MM） as the control.【Result】During the experimental period, the daily ET0 varied from 0.49 to 6.04 mm/d with an average of 2.43 mm/d. The evapotranspiration calculated using all models was linearly correlated（R^2〉0.9） to the values calculated from the P-MM,with the FAO-24 having RMSE=0.40 mm/d and NSE=0.93, the Irmak-Allen having RMSE=0.67 mm/d and NSE=0.81, and the Priestley-Taylor having RMSE=0.76 mm/d and NSE=0.76. The FAO-56 Penman-Monteith model was widely used in the field, but its application to the greenhouse was unsatisfactory with RMSE=1.18 mm/d and NSE=0.41.【Conclusion】Comparing all available models showed that the Irmak-Allen model is most suitable for calculating ET0 in the greenhouses.