Impact of the Spatial Domain Size on the Performance of the Ts-VI Triangle Method in Terrestrial Evapotranspiration Estimation

Remote Sensing

Jing Tian²  Hongbo Su²  Xiaomin Sun¹  Shaohui Chen²  Honglin He¹ 

[1] Key Laboratory of Ecosystem Network Observation and Modeling, IGSNRR, CAS, A11 Datun Road, Beijing 100101, China; E-Mails:;Key Laboratory of Water Cycle and Related Land Surface Processes, Institute of Geographical Sciences and Natural Resources Research (IGSNRR), Chinese Academy of Sciences (CAS), A11 Datun Road, Beijing 100101, China; E-Mails:

关键词: triangle method;    evapotranspiration estimation;    spatial domain size;    limiting boundaries of T_s-VI space;   

DOI  :  10.3390/rs5041998

来源: mdpi

【 摘 要 】

This study aims to investigate the impact of the spatial size of the study domain on the performance of the triangle method using progressively smaller domains and Moderate Resolution Imaging Spectroradiometer (MODIS) observations in the Heihe River basin located in the arid region of northwestern China. Data from 10 clear-sky days during the growing season from April to September 2009 were used. Results show that different dry/wet edges in the surface temperature-vegetation index space directly led to the deviation of evapotranspiration (ET) estimates due to the variation of the spatial domain size. The slope and the intercept of the limiting edges are dependent on the range and the maximum of surface temperature over the spatial domain. The difference of the limiting edges between different domain sizes has little impact on the spatial pattern of ET estimates, with the Pearson correlation coefficient ranging from 0.94 to 1.0 for the 10 pairs of ET estimates at different domain scales. However, it has a larger impact on the degree of discrepancies in ET estimates between different domain sizes, with the maximum of 66 W·m⁻². The largest deviation of ET estimates between different domain sizes was found at the beginning of the growing season.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland