干旱区生态环境知识资源中心(Arid): Analysis of the Diurnal Pattern of Evaporative Fraction and Its Controlling Factors over Croplands in the Northern China

Arid

	Analysis of the Diurnal Pattern of Evaporative Fraction and Its Controlling Factors over Croplands in the Northern China
	Yang Dawen; Chen He; Lei Huimin
来源期刊	Journal of Integrative Agriculture
ISSN	2095-3119
出版年	2013
卷号	12 期号:8 页码:1316-1329
英文摘要	A key issue of applying remotely sensed data to estimate evapotranspiration (ET) for water management is extrapolating instantaneous latent heat flux (LE) at satellite over-passing time to daily ET total. At present, the most commonly used extrapolation methods have the same assumption that evaporative fraction (EF) can be treated as constant during daytime (so-called EF self-preservation). However, large errors are reported by many documents over various ecosystems with the same approach, which indicates that further analysis of the diurnal pattern of EF is still necessary. The aim of this study is to examine the diurnal pattern of EF under fair weather conditions, then to analyze the dependencies of EF to meteorological and plant factors. Long-term flux observations at four sites over semi-arid and semi-humid climate regions in the northern China are used to analyze the EF diurnal pattern. Results show that the EF self-preservation assumption no longer holds over growing seasons of crops. However, the ratio of reference ET to available energy is almost constant during the daytime, which implies the climate factors do not have much effect on the variability of EF. The analysis of diurnal pattern of air temperature, vapor pressure deficiency (VPD), and relative humidity (RH) confirms the assumption that ET diurnal pattern is mainly influenced by stomatal regulation.
英文关键词	evaporative fraction daily evapotranspiration meteorological factor vegetation fraction northern China
类型	Article
语种	英语
开放获取类型	Other Gold
收录类别	CSCD
WOS研究方向	Geology
CSCD记录号	CSCD:4922168
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/335260
作者单位	Yang Dawen, Department of Hydraulic Engineering, Tsinghua University, State Key Laboratory of Hydroscience and Engineering, Beijing 100084, China.; Chen He, Department of Hydraulic Engineering, Tsinghua University, State Key Laboratory of Hydroscience and Engineering, Beijing 100084, China.; Lei Huimin, Department of Hydraulic Engineering, Tsinghua University, State Key Laboratory of Hydroscience and Engineering, Beijing 100084, China.
推荐引用方式 GB/T 7714	Yang Dawen,Chen He,Lei Huimin. Analysis of the Diurnal Pattern of Evaporative Fraction and Its Controlling Factors over Croplands in the Northern China[J],2013,12(8):1316-1329.
APA	Yang Dawen,Chen He,&Lei Huimin.(2013).Analysis of the Diurnal Pattern of Evaporative Fraction and Its Controlling Factors over Croplands in the Northern China.Journal of Integrative Agriculture,12(8),1316-1329.
MLA	Yang Dawen,et al."Analysis of the Diurnal Pattern of Evaporative Fraction and Its Controlling Factors over Croplands in the Northern China".Journal of Integrative Agriculture 12.8(2013):1316-1329.