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运用涡度相关仪、包裹式茎流计对半干旱区玉米蒸散和蒸腾进行连续观测,并对田间土壤水势及其周围气象因子进行同步监测,分析了玉米蒸散和蒸腾在不同时间尺度上的变化过程及其影响因素,结果表明:①涡度相关仪测定的日蒸散量和茎流计测定的日腾量变化规律一致,相关性较好,但日内蒸散速率和蒸腾速率的变化受环境因子的影响而呈现不同的变化特征;②不同深度土壤水分状况对玉米蒸散和蒸腾存在不同影响。对玉米蒸散起较大作用的是地表以下10~15cm深处的土壤水势,而对玉米蒸腾起较大作用的是15~20cm深处的土壤水势;③在不同时间尺度上,太阳辐射始终是影响玉米蒸散和蒸腾的最主要气象因子;但在日内变化上,玉米蒸散速率和蒸腾速率与太阳辐射和饱和水汽压差均存在较好的相关关系。
The evapotranspiration and transpiration of maize in the semi-arid area were monitored continuously by using the eddy covariance analyzer and the wrapped stemflow meter. The soil water potential and the surrounding meteorological factors in the field were monitored simultaneously. The changes of transpiration and transpiration of maize at different time scales were analyzed The results showed that: (1) The daily evapotranspiration measured by eddy covariance was consistent with that of the Stem flow, and the correlation was good. However, the variation of transpiration rate and evapotranspiration rate were affected by environmental factors Which showed different characteristics of variation; (2) Soil moisture at different depths had different effects on evapotranspiration and transpiration of maize. The greater the role of maize evapotranspiration is the soil water potential at the depth of 10 ~ 15cm below the surface, while the greater the role of maize transpiration is the depth of 15 ~ 20cm soil water potential; ③ in different time scales, the solar radiation is always The main meteorological factors affecting the transpiration and transpiration of maize were the same. However, there was a good correlation between the transpiration rate and the transpiration rate of solar radiation and the pressure difference of saturated vapor in the diurnal variation.