Evaluation of actual evapotranspiration measured by large-scale weighing lysimeters in a humid alpine meadow, northeastern Qinghai-Tibetan Plateau

NWIPB OpenIR

	Evaluation of actual evapotranspiration measured by large-scale weighing lysimeters in a humid alpine meadow, northeastern Qinghai-Tibetan Plateau
	Dai, Licong; Fu, Ruiyu; Guo, Xiaowei; Ke, Xun; Du, Yangong; Zhang, Fawei; Li, Yikang; Qian, Dawen; Zhou, Huakun; Cao, Guangmin
	2021
发表期刊	HYDROLOGICAL PROCESSES
卷号	35 期号:4
摘要	The accurate estimation of evapotranspiration (ET) is essential for assessing water availability and requirements of regional-scale terrestrial ecosystems, and for understanding the hydrological cycle in alpine ecosystems. In this study, two large-scale weighing lysimeters were employed to estimate the magnitude and dynamics of actual evapotranspiration in a humid alpine Kobresia meadow from January 2018 to December 2019 on the northeastern Qinghai-Tibetan Plateau (QTP). The results showed that daily ETa averaged 2.24 +/- 0.10 mm day (-1) throughout the study period, with values of 3.89 +/- 0.14 and 0.81 +/- 0.06 mm day(-1) during the growing season and non-growing season, respectively. The cumulative ETa during the study period was 937.39 mm, exceeding precipitation (684.20 mm) received at the site during the same period by 37%, suggesting that almost all precipitation in the lysimeters was returned to the atmosphere by evapotranspiration. Furthermore, the cumulative ETa (805.04 mm) was almost equal to the maximum potential evapotranspiration estimated by the FAO-56 reference evapotranspiration (ET0) (801.94 mm) during the growing season, but the cumulative ETa (132.25 mm) was 113.72% less than the minimum equilibrium ETeq) (282.86 mm) during the non-growing season due to the limited surface moisture in frozen soil. The crop coefficient (K-c) also showed a distinct seasonal pattern, with a monthly average of 1.01 during the growing season. Structural equation model (SEM) and boosted regression tree (BRT) show that net radiation and air temperature were the most important factors affecting daily ETa during the whole study period and growing season, but that non-growing season ETa was dominated by soil water content and net radiation. The daily K-c was dominated by net radiation. Furthermore, both ETa and K-c were also affected by aboveground biomass.
关键词	alpine ecosystem boosted regression trees hydrological cycles Qinghai‐ Tibetan Plateau structural equation models
文献类型	期刊论文
条目标识符	http://210.75.249.4/handle/363003/60822
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	Dai, Licong,Fu, Ruiyu,Guo, Xiaowei,et al. Evaluation of actual evapotranspiration measured by large-scale weighing lysimeters in a humid alpine meadow, northeastern Qinghai-Tibetan Plateau[J]. HYDROLOGICAL PROCESSES,2021,35(4).
APA	Dai, Licong.,Fu, Ruiyu.,Guo, Xiaowei.,Ke, Xun.,Du, Yangong.,...&Cao, Guangmin.(2021).Evaluation of actual evapotranspiration measured by large-scale weighing lysimeters in a humid alpine meadow, northeastern Qinghai-Tibetan Plateau.HYDROLOGICAL PROCESSES,35(4).
MLA	Dai, Licong,et al."Evaluation of actual evapotranspiration measured by large-scale weighing lysimeters in a humid alpine meadow, northeastern Qinghai-Tibetan Plateau".HYDROLOGICAL PROCESSES 35.4(2021).