• 研究论文 •

不同参考温度取值对三温模型反演植被蒸腾精度的影响

1. 北京大学深圳研究生院环境与能源学院, 广东深圳 518055
• 收稿日期:2021-06-08 接受日期:2021-07-05 出版日期:2022-04-20 发布日期:2021-08-02
• 通讯作者: 鄢春华,邱国玉
• 作者简介:(qiugy@pkusz.edu.cn)
*(yanch@pku.edu.cn);
• 基金资助:
国家自然科学基金(42001022);中国博士后科学基金(2019M660330)

Effects of different reference temperature values on the accuracy of vegetation transpiration estimation by three-temperature model

XIONG Bo-Wen, LI Tong, HUANG Ying, YAN Chun-Hua*(), QIU Guo-Yu*()

1. School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen, Guangdong 518055, China
• Received:2021-06-08 Accepted:2021-07-05 Online:2022-04-20 Published:2021-08-02
• Contact: YAN Chun-Hua,QIU Guo-Yu
• Supported by:
National Natural Science Foundation of China(42001022);China Postdoctoral Science Foundation(2019M660330)

Abstract:

Aims Parameterization of reference temperature has always been the key and difficult part in calculating evapotranspiration and its evaporation and transpiration components by using three-temperature model. In this paper, the best value of reference temperature was determined by quantifying and comparing the influence of different reference temperature values on the accuracy of transpiration estimation by three-temperature model.

Methods Based on the Bowen ratio and thermal infrared observation data of a typical urban lawn, sensitivity analysis and error analysis were carried out on the input variables involved in the sub-model of the three-temperature model to determine the most critical variables for the accuracy of transpiration estimation. Then the influence of input variables parameterization on the calculation of transpiration was quantified and compared to determine the best value of reference temperature.

Important findings When using the three-temperature model, the best estimation is to select the maximum temperature of the whole piece of paper as the reference leaf temperature (R2 = 0.91, root mean square error (RMSE) = 0.078 mm·h-1). When the maximum value of the vegetation canopy temperature was used as the reference temperature, it is directly assumed that the transpiration at the maximum temperature of the vegetation is zero (there is a certain transpiration rate in fact). Therefore, it is easy to underestimate the actual transpiration, resulting in that the estimation accuracy of the three-temperature model was slightly lower than the accuracy of using the maximum value of the reference leaf temperature, but the estimation effect is still good (R2 = 0.87, RMSE = 0.080 mm·h-1). Therefore, considering the limitations of the reference leaf settings, if the reference leaf temperature cannot be measured in practical applications, the maximum temperature of the vegetation canopy as the reference temperature can be used to achieve good estimate results.