Simplified Priestley–Taylor Model to Estimate Land-Surface Latent Heat of Evapotranspiration from Incident Shortwave Radiation, Satellite Vegetation Index, and Air Relative Humidity

Remote Sensing

Xiangyi Bei¹  Junming Yang¹  Xiaozheng Guo¹  Zhiqiang Xiao¹  Zijing Xie¹  Xiaotong Zhang¹  Ke Shang¹  Ruiyang Yu¹  Kun Jia¹  Yunjun Yao¹  Zhenhua Di¹ 

[1] Faculty of Geographical Science, Beijing Normal University, Beijing 100875, China;

关键词: SPT model;    GLASS product;    NDVI;    terrestrial latent heat flux;    eddy covariance;   

DOI  :  10.3390/rs13050902

来源: DOAJ

【 摘 要 】

An operational and accurate model for estimating global or regional terrestrial latent heat of evapotranspiration (ET) across different land-cover types from satellite data is crucial. Here, a simplified Priestley–Taylor (SPT) model was developed without surface net radiation (Rn) by combining incident shortwave radiation (Rs), satellite vegetation index, and air relative humidity (RH). Ground-measured ET for 2000–2009 collected by 100 global FLUXNET eddy covariance (EC) sites was used to calibrate and evaluate the SPT model. A series of cross-validations demonstrated the reasonable performance of the SPT model to estimate seasonal and spatial ET variability. The coefficients of determination (R²) of the estimated versus observed daily (monthly) ET ranged from 0.42 (0.58) (p < 0.01) at shrubland (SHR) flux sites to 0.81 (0.86) (p < 0.01) at evergreen broadleaf forest (EBF) flux sites. The SPT model was applied to estimate agricultural ET at high spatial resolution (16 m) from Chinese Gaofen (GF)-1 data and monitor long-term (1982–2018) ET variations in the Three-River Headwaters Region (TRHR) of mainland China using the Global LAnd-Surface Satellite (GLASS) normalized difference vegetation index (NDVI) product. The proposed SPT model without Rn provides an alternative model for estimating regional terrestrial ET across different land-cover types.

【 授权许可】

Unknown