西北干旱和半干旱地区地表蒸发计算方法评估应用

针对我国西北地区干旱和半干旱的气候特征，以及相对简单的地表覆盖特点，论证了互补相关模型计算西北地区蒸发量的可行性。通过中国科学院山东禹城试验站农田观测资料，分析了植被多样性分布对互补相关模型的影响。得出植被的多样性以及植被物候变化的非同步变化是造成互补相关模型中关键参数——大尺度平流参数季节变化的重要原因。并利用遥感反演参数和气象台站观测数据计算了覆盖类型相对单一的西北地区蒸发。结果表明，蒸发与地表覆盖类型的空间分布一致，与气象台站20 cm蒸发皿观测数据呈现空间互补特征，其季节变化与区域降水、温度和植被物候变化相吻合。  

Evaluation for a Method of Evapotranspiration in Arid and Semi-arid Regions of Northwest China

In view of the characteristics of the arid climate and simple land surface types in the northwest of China, Complementary Relationship Model (CRM) is discussed to evaluate its precision in calculation. By using the observational data from Yucheng experimental station which is located in Shangdong Province, the influence of vegetation diversity on CRM is analysed. The result shows that the distributions of vegetation diversity and no in-phase phenology are two important reasons that cause large-scale advection parameter, a primary parameter in CRM, to change with the seasons. At last, CRM is applied in the northwest of China. The real evapotranspiration from CRM is essentially uniform with the distribution of land surface types, and presents complementary characteristics compared with that from the 20 cm caliber evaporating dish, and similar seasonal change characteristic to precipitation, temperature, and phenology.