基于Penman-Monteith方程的节水灌溉稻田蒸散量模型

为利用Penman-Monteith方程直接计算非充分灌溉条件下的稻田蒸散量，该文根据国家“863”节水农业重大专项试验资料，在K-P表层阻抗模型修正研究基础上，提出改进的稻田蒸散量模拟模型。结果表明：根据土壤相对含水率修正后的K-P模型较好地模拟了水稻表层阻抗，且反映出不同土壤水分状况下表层阻抗的变化规律；采用改进的Penman-Monteith方程模拟水分胁迫条件下的稻田蒸散量后，误差从改进前的18.57%降低至10.84%，且对冠层未完全覆盖条件下的稻田蒸散量也具有较好的模拟效果；土壤含水率、空气温度和空气湿度是改进的Penman-Monteith方程最为敏感的因子，它们的准确观测对于提高模型的估算精度至关重要；模型回归系数（c1、c0）的变化对模型估算结果的影响较小。表明当某一特定作物的回归系数值确定后，改进的Penman-Monteith方程可应用于不同地区、不同灌溉模式下作物蒸发蒸腾量的估算。

Estimation of rice evapotranspiration under controlled irrigation by using Penman-Monteith method

Based on the experimental data from the 863 National Key Project on water-saving agriculture, evapotranspiration of paddy rice under controlled irrigation condition was estimated by using a mended Penman-Monteith method presented in this paper with a variable canopy resistance.Results showed that canopy resistance could be estimated better by adopting Penman-Monteith model which modified by soil moisture content. Variation of canopy resistance under different water conditions was revealed at the same time.R...