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蒸散是地表水热交换的主要过程,其空间特征差异明显,而遥感技术的发展与应用使得区域蒸散估算成为现实。本文介绍了基于能量平衡法的单层与双层遥感蒸散模型,并对这2类遥感模型的优缺点分别进行了评述和比较。重点综述了近年来得到发展和应用的大气-陆地交换反演模型(ALEXI),阐述其主要结构、特色和过程。该模型通过耦合双层能量平衡模型(TSEB)和简化边界层模型,减少以往模型对台站气象数据的依赖,明显提高区域蒸散估算精度。研究表明,基于该模型的蒸散胁迫指数(ESI)具有很强的区域干旱监测能力。在今后研究中,多元遥感数据融合技术、陆面数据同化系统与遥感蒸散模型的结合将成为该领域的研究热点。
Evapotranspiration is the main process of surface water heat exchange, and its spatial characteristics are obviously different. However, the development and application of remote sensing technology makes regional evapotranspiration estimation a reality. In this paper, single-layer and double-layer remote sensing evapotranspiration models based on energy balance method are introduced, and the advantages and disadvantages of these two kinds of remote sensing models are respectively reviewed and compared. This paper mainly reviews the ALEXI model developed in recent years and its application, and expounds its main structure, characteristics and process. The model reduces the reliance of the previous model on station meteorological data by coupling the two-layer energy balance model (TSEB) and simplifying the boundary layer model, and obviously increases the estimation accuracy of regional evapotranspiration. Studies have shown that evapotranspiration stress index (ESI) based on this model has strong ability of regional drought monitoring. In the future research, the combination of multivariate remote sensing data fusion, land surface data assimilation system and remote sensing evapotranspiration model will become the research hotspot in this field.