区域蒸散发遥感模型研究的进展

本文主要介绍了目前常用的几类遥感蒸散发模型,包括基于能量平衡的单层与双层蒸散发模型、彭曼模型以及基于植被指数和地表温度的经验模型等,并对这些模型各自的优缺点分别进行了评述。由于地表水热过程的复杂性,在区域蒸散发模拟中仍存在很多亟待解决的问题,如地表特征参数和地表温度反演中的不确定性,遥感反演在不同时空尺度上扩展的困难以及由此带来的区域验证问题等。因此要提高区域蒸散发反演的精度,必须进一步提高遥感辐射传输模型的精度,降低遥感输入数据和反演参数中存在的不确定性,同时通过不同尺度的田间观测试验加强对地表水热传输机理等方面的研究。此外,遥感和陆面过程模型的结合能有效降低模型和数据中的不确定性,陆面过程同化模型能提供更为可靠的连续的地表水热过程模拟,是一个很有前途的发展方向。

Review of study on regional evapotranspiration modeling based on remote sensing

A review of research progress concerning the application of remote sensing for regional evapotranspiration(ET) estimation,including the surface energy balance models,Penman-Monteith equation,empirical models etc.,was presented. Problems and difficulties occurred to the progress in this field,including the retrieve of land surface parameters from remote sensing data,the scale problem and the validation of the remote sensing models were also outlined.It is pointed out that the future studies should devote to the radiation transfer models to reduce the uncertainty in the parameter retrieval,and field observations in different scales are also necessary for enhancing the understanding of the water and energy coupling transfer scheme between land and atmosphere.Additionally,the combination of remote sensing and land surface models can reduce the uncertainty in the modeling of land surface processes and remote sensing retrievals.Therefore,the land data assimilation system is promising in providing accurate and continuous prediction of the land surface fluxes.