北京林业大学学报2018，Vol.40Issue(12)：1-8,8.DOI:10.13332/j.1000-1522.20180145
毛乌素沙地油蒿灌丛Priestley-Taylor模型系数研究
Priestley-Taylor model coefficient in a typical Artemisia ordosica shrubland in Mu Us Sandy Land of northwestern China
摘要
Abstract
[Objective] Estimating evapotranspiration (ET) based on the semi-empirical and semitheoretical Priestly-Taylor model (PT) mainly relies on accurately determining the appropriate value ofthe model coefficient α in a specific study area. This study expored the applicability of the model coefficient α. Localization studies have been conducted to more accurately estimate evapotranspiration in arid and semi-arid regions. [Method] This paper used the eddy covariance technique combined with micro-meteorological data to monitor the water and heat transfer processes of a typical Artemisia ordosica shrubland in growing season in Mu Us Sandy Land of northwestern China to quantify the seasonal variations in α coefficients. [Result] The results showed that the actual α coefficient had significant seasonal variations, peaking during the leafing period, and remaining relatively plateau during expanded leaf period and the leaf discoloration period. The maximum α coefficient was 0. 66 and the minimum value was 0. 03, averaging 0. 23 in growing season. There was a logarithmic positive correlation betweenα coefficient and canopy conductance and saturated vapor pressure difference in the growing season. Soil water content (30 cm belowground) and leaf area index were positively correlated with α coefficient.Evapotranspiration estimated from the PT model with α = 1. 26 and with α = 0. 50, which was calculated from the wind speed data at 2 m height, was significantly larger than the measured evapotranspiration.The recommended localization value of the improved PT model coefficient α was 0. 23, which gave better estimation of ET, linear gradient was 0. 72, R2 was 0. 57. [Conclusion] Therefore, the modified PT model can be used to accurately estimate evapotranspiration in arid and semi-arid regions.关键词
Priestley-Taylor模型系数/蒸散发/涡度相关法/半干旱区/油蒿Key words
Priestley-Taylor model coefficient/evapotranspiration/eddy covariance/semi-arid region/Artemisia ordosica分类
农业科技引用本文复制引用
梁椿烜,马景永,杨睿智,吴雅娟,田赟,贾昕,查天山,杨林..毛乌素沙地油蒿灌丛Priestley-Taylor模型系数研究[J].北京林业大学学报,2018,40(12):1-8,8.基金项目
国家自然科学基金项目(31670710、31670708) （31670710、31670708）
中央高校基本科研业务费专项(2015ZCQ-SB-02) （2015ZCQ-SB-02）
