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【目的】用Penman-Monteith(P-M)简化公式代替标准的Penman-Monteith公式计算参考作物的潜在蒸腾量。【方法】通过2008～2010年鄯善试验站的气象资料,对Penman-Monteith简化公式(忽略饱和差项)计算的参考作物潜在腾发量(ET0)与FAO推荐的P-M公式计算的参考作物潜在腾发量(ET0(PM))进行比较。【结果】Penman-Monteith简化公式计算的ET0年值略小于Penman-Monteith公式计算的年值,其绝对偏差为75～114 mm,相对偏差为10.5%～14.3%,变异系数分别为0.04和0.06,简化公式的计算稳定性略好于标准的PM公式。两种方法计算的参考作物潜在腾发强度的月变化相近,统计分析的标准差分别为0.80和0.83,变异系数分别为0.23和0.2。空气动力学项中的饱和差项是Penman-Monteith简化公式和标准Penman-Monteith公式的主要差别,通过回归分析表明两种公式计算的参考作物潜在腾发量具有显著的线性相关性,各月a值很接近,差值最大为0.08,最小仅为0.004 1,较好的说明了空气动力学项中的饱和差项对参考作物潜在腾发量的影响较小。【结论】在极端干旱区可利用Penman-Monteith简化公式代替标准的Penman-Monteith公式计算参考作物的潜在蒸腾量。
【Objective】 Potential transpiration of reference crops was calculated by Penman-Monteith (P-M) simplified formula instead of standard Penman-Monteith formula. 【Method】 Based on the meteorological data of Shanshan test station from 2008 to 2010, the reference crop potential (ET0) calculated by Penman-Monteith’s simplified formula (ignoring the saturated difference term) and the FAO reference PM formula Evapotranspiration (ET0 (PM)) for comparison. 【Result】 The results of Penman-Monteith simplification formula showed that the annual value of ET0 was calculated by Penman-Monteith formula with the absolute deviation of 75-114 mm, the relative deviation of 10.5% -14.3%, the coefficient of variation of 0.04 and 0.06, respectively. The computational stability of the simplified formula is slightly better than the standard PM formula. The monthly variations of potential evapotranspiration of reference crops calculated by the two methods were similar, with standard deviations of 0.80 and 0.83 for statistical analysis and coefficients of variation of 0.23 and 0.2 respectively. The main difference between the Penman-Monteith formula and the standard Penman-Monteith formula is the saturation difference in the aerodynamics term. Regression analysis shows that the potential evapotranspiration of the reference crops calculated by the two formulas has a significant linear correlation. Each month a The value is very close, the maximum difference is 0.08, the minimum is only 0.004 1, which better shows that the difference of the saturated part in the aerodynamic term has less influence on the potential evapotranspiration of the reference crop. 【Conclusion】 The potential evapotranspiration of reference crops can be calculated by Penman-Monteith’s simplified formula instead of standard Penman-Monteith formula in the extremely arid region.