基于预报气温和HS公式估算麦季参考作物蒸散量

Estimation of Reference Crop Evapotranspiration in Wheat Season Based on Forecast Temperature and HS Formula

为了精准评价基于预报气温和Hargreaves-Samani (HS)公式计算参考作物蒸散量的可行性和准确性,基于1961—2017年新乡历史气象数据以Penman-Monteith (PM)公式计算结果对HS公式参数进行了校正,采用预报气温数据通过修正后的HS公式计算2018—2020年冬小麦生长季节的参考作物蒸散量。以Penman-Monteith计算的参考作物蒸散量为对照值进行对比,结果表明用Hargreaves-Samani(HS)公式和预报气温估算的日参考作物蒸散量与Penman-Monteith计算的参考作物蒸散量相关程度较高,平均绝对误差为0.48 mm/d,均方根误差为0.64 mm/d,决定系数为0.84,拟合度为0.96。说明在华北地区用日预报气温资料采用Hargreaves-Samani(HS)公式估算参考作物蒸散量这一方法可行,这为农业灌溉预报提供了理论和方法上的保证,并且对指导当地农业水资源配置具有参考意义。

In order to accurately evaluate the feasibility and accuracy of calculating reference crop evapotranspiration(ET0)based on predicted temperature and Hargreaves samani(HS)formula,the parameters of HS formula were corrected by using the historical meteorological data of Xinxiang from 1961 to 2017 and the results of Penman Monteith(PM)formula.The reference crop evapotranspiration in the growing season of winter wheat from 2018 to 2020 was calculated by using the predicted temperature data and the modified HS formula.Comparing the reference crop evapotranspiration calculated by penman Monteith,the results showed that the estimated daily reference crop evapotranspiration by Hargreaves samani(HS)formula was highly correlated with the reference crop evapotranspiration calculated by penman Monteith.The average absolute error was 0.48 mm/d,the root mean square error was 0.64 mm/d,coefficient of determination was 0.84 and the fitting degree was 0.96.Therefore,it was feasible to use Hargreaves samani(HS)formula to estimate reference evapotranspiration with daily forecast temperature data in Huanghuaihai area,which provided a theoretical and methodological guarantee for agricultural irrigation prediction,and had reference significance for guiding the allocation of local agricultural water resources.