为提高地表能量平衡系统(SEBS)模型在干旱水分胁迫条件下估算地表通量的精度,引入归一化植被水分指数(NDWI)作为干旱水分胁迫信息,以线性、指数、S曲线3种不同形式结合到SEBS模型的kB^-1系数中,使得kB^-1。随着水分胁迫的增加而减小,从而提高SEBS模型估算地表通量的精度。以黑河流域盈科绿洲为研究区域,选取2008—2009年的气象和通量观测数据对模型进行标定和验证。研究结果表明:存在干旱水分胁迫时,与原始SEBS模型相比,考虑干旱水分胁迫信息的SEBS模型能够更为准确地估算地表通量。这种方案能够较为有效地改善原始SEBS模型低估感热通量高估潜热通量的现象,将感热通量的偏差减小35W/m^2,潜热通量的偏差减小25W/m^2。
To improve the accuracy of land surface fluxes estimated by the Surface Energy Balance System (SEBS) under drought water stress conditions, the normalized difference water index (NDWI) as drought water stress information is integrated into SEBS to modify the value of parameter ( kB^-1) based on linear, exponential, and S-curve equations, which decreases with the increase in water stress. The proposed scheme is calibrated and validated by mete- orological and fluxes observations in 2008--2009 from the Yingke oasis station of Heihe river basin, China. Results show that the revised SEBS model can significantly improve the land surface flux estimation in arid and semi-arid regions under drought water stress conditions. The issues of underestimation of sensible heat fluxes and overestimation of latent heat fluxes with the standard SEBS can be significantly improved by the revised SEBS. Biases in estimated sensible and latent heat fluxes'are reduced by 35 W/m^2and 25 W/m^2, respectively.