基于SPAC系统的作物腾发量模型的试验研究

Experimental study on crop evaportranspiration model based on SPAC system

通过田间试验对河北省2004年和2005年棉花、冬小麦和夏玉米不同生育期的冠层温度、地表温度和叶面积指数进行测定,根据能量平衡方程和空气动力学方程,结合当地气象资料推导出作物腾发量模型,并与棉花、冬小麦和夏玉米不同生育期实际腾发量比较发现:作物腾发量模型计算值不仅反映了这3种作物不同生育期腾发量的变化规律,而且与实际腾发量平均值的相对误差2004年分别为8.46%、4.76%和12.85%,2005年分别为3.42%、1.65%和0.84%,因此可以利用作物腾发量模型来计算作物腾发量,该研究为监测土壤墒情和确定作物缺水指标提供了理论依据。

The canopy temperature, land surface temperature and leaf area index of cotton, winter wheat and summer corn in different growth periods were determined basing on the field experiment in the year of 2004 and 2005. The model of crop evaportranspiration was established on the foundation of the local meteorological data, energy balance equation and aerodynamic equation, and calculated values of the crop evapotranspiration model were compared with actual evapotranspiration of cotton, winter wheat and summer corn in different growth speriods. The results show that the calculating values of the crop evaportranspiration model not only indicate the variation rule of these three kinds of crop evaportranspiration in different growth periods, but also indicate relatively error of the average values between calculating value and actual evapotranspiration with 8.46%, 4.76% and 12.85% in 2004 respectively; 3.42%, 1.65% and 0.84% in 2005 respectively. So the model of crop evaportranspiration can be used to calculate crop evaportranspiration, and it also provides the theoretical foundation for monitoring the soil moisture and calculating the crop water stress index.