水分胁迫条件下膜下滴灌作物蒸发蒸腾量计算模式的研究

Evapotranspiration estimation model for film-mulched and drip-irrigated crop under water stress condition

研究了充分供水和水分胁迫条件下膜下滴灌棉花的需水规律,确定了膜下滴灌棉花作物系数Kc的分布规律,根据作物水分胁迫指标CWSI的物理意义,建立了水分胁迫条件下CWSI和作物实际蒸发蒸腾量ETa的函数关系。依据实测的ET0、Kc以及不同水分处理各生育阶段的CWSI值,计算出干旱缺水条件下膜下滴灌棉花的ETa,同实测值相比单生育阶段的计算值相对误差在16%以下,全生育期相对误差不到4%。

The water use characters of cotton with drip-irrigation under film mulch were measured under the condition of sufficient and deficient water, and the crop coefficients （Kc） were determined for different growth stages. Based on the physical meaning of crop water stress index （CWSI）, the function relationship between CWSI and crop actual evapotranspiration （ETa） was established. The ETa of cotton with drip-irrigation under film mulch could be calculated by the measurement value of ET0, Kc and CWSI of different stages. The relative error between calculated and measured ETa. was less than 16% in single growth stage, and less than 4% for whole growth period.