title: [Evapotranspiration of winter wheat field in North China Plain].
abstract: By using eddy covariance and remote sensing techniques, the relationships between winter wheat soil moisture content and farmland evapotranspiration or canopy temperature were analyzed at field scale under various environmental conditions in the North China Plain. The results showed that when the soil moisture content was below 65% of field capacity, the evaporative fraction under full canopy was low and stable during the middle part of clear days. Under clear sky condition, there was a good non-linear correlation between latent heat flux and crop canopy temperature with diurnal and seasonal patterns. The temperature difference between crop canopy and air as well as the relative evapotranspiration had a close link to the relative moisture content of 0 - 100 cm soil layer. Based on the in situ measurements of daily evapotranspiration amount (ET(d)), daily net radiation flux (Rn(d), mm), average canopy temperature (T(e), degrees C) from 13 : 30 to 14: 00, and daily maximum air temperature (T(a max), degrees C) during the field experiment, the parameters of simplified estimation model for daily evapotranspiration were established.
authors.affiliation: Water Resources and Dryland Farming Laboratory, Institute of Agricultural Environment and Sustainable Development, Chinese Academy of Agricultural Sciences, Beijing 100081, China. gsfmn@tom.com
authors.forename: Jiaxuan
authors.initials: J
authors.lastname: Guo
authors.forename: Yuzhong
authors.initials: Y
authors.lastname: Li
authors.forename: Chang-Rong
authors.initials: CR
authors.lastname: Yan
authors.forename: Quansheng
authors.initials: Q
authors.lastname: Zhao
authors.forename: Xurong
authors.initials: X
authors.lastname: Mei
mesh_terms: D002681:China; D018526:Plant Transpiration / Q000502:physiology*; D012621:Seasons; D012987:Soil / Q000032:analysis*; D014908:Triticum / Q000502:physiology*; D014867:Water / Q000032:analysis*
chemical_list: D012987:Soil; D014867:Water