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作 者 ：郭家选^1,2;李玉中¹;严昌荣¹;赵全胜¹;梅旭荣¹

期 刊 ：应用生态学报 2006年 17卷 12期 页码：2357-2362

关键词：小麦；

摘 要 ：以华北平原冬小麦农田为研究对象，采用涡度相关技术和热红外遥感技术，研究了不同环境条件下土壤含水量与农田蒸散量及作物冠层温度的关系.结果表明，冬小麦在农田郁闭(LAI≥3)、晴天和土壤相对含水量低于田间持水量65%的情况下，蒸发比值日变化正午前后出现相对较低且平稳的变化趋势.在晴天情况下，农田潜热通量与作物冠层温度日变化和季节变化均呈极显著的非线性相关关系，而冠气温差、农田相对蒸散量则与0～100 cm土层的土壤相对含水量密切相关.以13:30～14:00的平均冠层温度值T_c、日最高气温T_{a max}和日净辐射总量Rn_d为统计数据，确立了冬小麦农田日蒸散量ET_d （mm）估算简化模式参数.

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_c, ℃) from 13:30 to 14:00, and daily maximum air temperature
(T_{a max},℃) during the field experiment, the parameters of simplified estimation
model for daily evapotranspiration were established.

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