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蒸散发是干旱、半干旱地区内陆河流域水分消耗的主要途径,利用遥感估算流域尺度上的蒸散发对内陆河流域水循环和水资源的合理利用具有重要的指导意义.基于2012年开展的黑河流域生态-水文过程综合遥感观测联合试验(Hi WATER)的观测资料和高分辨率的ASTER影像,分别利用SEBAL模型和改进的SEBAL(M-SEBAL)模型估算黑河中游不同时期戈壁、绿洲等不同下垫面的蒸散发,通过涡动观测数据对比分析了SEBAL模型和M-SEBAL模型估算戈壁、绿洲蒸散发的精度.结果表明:SEBAL模型在绿洲低估感热通量,高估潜热通量;在戈壁高估感热通量,低估潜热通量.M-SEBAL模型充分考虑不同下垫面地表辐射温度与植被覆盖度之间的关系,能很好地反映不同植被覆盖区域的湍流通量的异质性,估算黑河中游戈壁、绿洲蒸散发的精度高于SEBAL模型.
Evapotranspiration is the main way of water consumption in inland river basins in arid and semi-arid regions, and the use of remote sensing to estimate evapotranspiration at river basin scales has important guiding significance for the rational utilization of water cycle and water resources in inland river basins.On the basis of Using the observation data of Hi WATER and high resolution ASTER images of the Heihe River Basin, the SEBAL model and the improved SEBAL (M-SEBAL) model were used to estimate the differences between the Gobi Desert and the oasis at different stages of the middle reaches of the Heihe River The evapotranspiration on the underlying surface and the eddy data were used to analyze the accuracy of SEBAL and M-SEBAL models in estimating evapotranspiration of the Gobi and Oasis.The results show that the SEBAL model underestimates the sensible heat flux in oasis and overestimates the latent heat flux, The sensible heat flux is overestimated in Gobi and the latent heat flux is underestimated.M-SEBAL model fully considers the relationship between surface radiation temperature and vegetation coverage of different underlying surfaces and can well reflect the turbulent fluxes of different vegetation cover areas Heterogeneity, accuracy of estimation of evapotranspiration in the middle reaches of Heihe Gobi and oasis is higher than SEBAL model.