基于互补相关原理的区域蒸散量估算模型比较

利用黄河流域1981~2000年期间的气象、水文资料,结合卫星遥感信息和数字高程模型,检验了平流-干旱、CRAE (Complementary Relationship Areal Evapotranspiration)、Granger等互补相关模型在不同时间尺度、不同气候类型区域上的计算精度,讨论了不同气候因子对计算误差的影响,并分析了模型参数的变化规律。结果表明：平流-干旱模型、CRAE和Granger模型估算的年蒸散量除了干旱年份外,误差都在10%以下。平流-干旱模型估算的月蒸散量比较合理,而CRAE模型与Granger模型都存在冬季月蒸散量估算过高的问题。平流-干旱模型与Granger模型的水量平衡闭合误差空间分布比较一致,计算效果是比较理想的,而CRAE模型的水量平衡闭合误差比较大。互补相关模型在湿润和干旱的条件下以及在可利用能量比较高和比较低的条件下,计算效果比较差。互补相关模型的经验参数在不同年型、不同气候类型区域有不同的最优值。

Comparison of Different Complementary Relationship Models for Regional Evapotranspiration Estimation

Based on meteorological and hydrological data in the Yellow River Basin covering 1981-2000, Advection-Aridity model, CRAE model and Granger model were validated at different temporal scales and in different climatic conditions by means of remote sensing and digital elevation model. Different climatic factors' effects on performance of models and variation characteristics of empirical parameters were analysed. Results show that with the exception of several extreme arid years, annual errors of Advection-Aridity model, CRAE model and Granger model were less than 10%. Monthly evapotranspirations from Advection- Aridity model were rational. However, CRAE model and Granger model overestimates monthly evapotranspirations during the winter. Spatial distribution of water balance closure errors for Advection-Aridity model is similar to that of Granger model. The closure errors for Advection-Aridity model and Granger model are less than that of CRAE model. In arid and humid climates or under more and less available energy conditions, Advection-Aridity model, CRAE model and Granger model did not perform very well.