非均匀地表蒸散遥感研究综述  

Remote sensing research of evapotranspiration over heterogeneous surfaces: A review

作　　者：周倜[1,2] 彭志晴[1,2] 辛晓洲[1] 李福根[1,2] 

机构地区：[1]中国科学院遥感与数字地球研究所遥感科学国家重点实验室,北京100101 [2]中国科学院大学,北京100049

出　　处：《遥感学报》2016年第2期257-277,共21页NATIONAL REMOTE SENSING BULLETIN

基　　金：中国科学院重点部署项目(编号:KZZD-EW-TZ-18);国家自然科学基金(编号:41371360)~~

摘　　要：本文评述了目前常用的遥感估算地表蒸散方法,包括地表能量平衡模型、Penman-Monteith类模型、温度—植被指数特征空间方法、Priestley-Taylor类模型和其他方法。然而使用这些方法估算地表蒸散时会面临严重的尺度效应,而产生尺度效应的根本原因之一是地表异质性,在分析了非均匀下垫面对水热通量遥感反演造成的影响后,介绍了面积加权、校正因子补偿与温度降尺度3种尺度误差纠正方法;并从地面观测实验的角度简述了非均匀下垫面水热通量真实性检验的研究;最后探讨了将来建立更具时空代表性的非均匀下垫面地表蒸散遥感估算模型可能会面临的一些挑战。This review surveys the most currently used evapotranspiration estimation methods based on remote sensing. The methods are divided into different categories, including surface energy balance models, Penman–Monteith models, land surface temperature–vegetation index space methods, Priestley–Taylor models, empirical statistical methods, complementary methods, and land process assimilation models. These methods are mainly focused on two problems. The first problem is how to deal with aerodynamic surface temperature used in gradient diffusion equation. One-source models have two major solutions. One is to use remotely sensed radiative temperature as a direct substitution for aerodynamic surface temperature or use semi-empirical relations to obtain the surface–atmospheric differential temperature.In two-source models, the heat fluxes are decomposed by component temperature. The second problem is how to calculate surface resistance that influences heat flux exchange from the soil surface and canopy layers. This process is complicated to calculate at the local scale.Basing from the two problems, scientists combined the features and superiority of remote sensing, such as the relationship between various vegetation indices and surface parameters with the fundamental theory of these methods, and developed these methods from saturated surface toward unsaturated surface to calculate evapotranspiration.However, severe scale effects emerge when these methods are used in heterogeneous surfaces. Surface heterogeneity influences the driving force of evapotranspiration estimation. Thus, three methods to correct scale error over heterogeneous surfaces are shown in detail： area weighting method, correction factor method, and land surface temperature downscaling（or thermal spatial sharpening） method. The core concepts of these methods are to couple high and low spatial resolution satellite data and statistically quantify the inhomogeneity in mixed pixels to correct the scale error in evapotranspiration estimation. In met

关 键 词：遥感 蒸散 模型 尺度效应 非均匀下垫面 地面实验 

分 类 号：P426.2[天文地球—大气科学及气象学] TP79[自动化与计算机技术—检测技术与自动化装置]