Regional evapotranspiration estimation based on a two-layer remote-sensing scheme in Shahe River basin

35th International Symposium on Remote Sensing of Environment

地球科学;生态环境科学

Yin, Jian^1,2 ; Wang, Huixiao^1

College of Water Sciences, Beijing Normal University, Beijing, China^1

School of Resources and Environment, Anqing Normal University, Anqing, China^2

关键词: Disaster monitoring;    Eddy correlations;    Estimation systems;    Large aperture scintillometers;    Regional evapotranspiration;    Remote sensing data;    Retrieval systems;    Surrounding regions;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/17/1/012141/pdf
DOI  :  10.1088/1755-1315/17/1/012141

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

Land surface evapotranspiration (ET) derived from remote sensing data has significant meaning for plant growth monitoring, crop yield assessment, disaster monitoring and understanding energy and water cycle in river basin area and surrounding regions. In the study, we developed a land surface ET remote sensing retrieval system to estimate the daily ET in Shahe river basin using the TMETM+ images. The system is based on the two-layer ET model and includes three parts: inversion of the evaporation ration using two-layer model, calculation of total daily net radiation, and estimation of daily ET based on evaporation fraction method. The results show that the average daily ET is about 2.28mm of the typical days in spring, and 2.97mm in summer, 1.59mm in autumn, and 0.5mm in winter. The ET in upstream areas covered by forest is higher than that in the downstream covered by settlement and farmland. In summer the difference of ET between the upper reaches and lower reaches is smaller compared to the other three seasons. The measurements by large aperture scintillometer and eddy correlation instrument were used for validation. By comparing the observed data with the estimated data, we found the estimation system had a high precision with the relative error between 0 and 16% (mean error of 11.1%), and the variance 0.77mm.