夏玉米农田蒸散量的变化特征及相关性分析

Variation Characteristics and Correlation Analysis of Evapotranspiration in Summer Maize Cropland

为了解夏玉米农田蒸散量特征,并根据蒸散特征指导农田灌溉,利用2018—2020年涡度相关系统获得的通量数据和气象数据,对夏玉米农田的蒸散量进行了分析,得到了夏玉米农田蒸散量的变化特征,通过对其与主要影响因素的相关性分析和拟合分析,得到了蒸散量与其主要影响因素的函数关系。相关性分析表明:夏玉米蒸散量与光合有效辐射、水汽压差均呈二次多项式关系;而与净辐射通量呈线性关系。利用单变量函数和双变量函数对蒸散量与其影响因素的关系进行拟合,结果表明:双变量函数的拟合效果优于单变量函数。

To understand the characteristics of evapotranspiration in summer maize cropland and guide farmland irrigation according to evapotranspiration,the flux data and meteorological data measured by the eddy covariance system from 2018 to 2020 were used to analyze the evapotranspiration of summer maize farmland,and the variation characteristics of evapotranspiration of summer maize farmland were obtained.The correlation between evapotranspiration and influencing factors was analyzed,and the functional relationships between evapotranspiration and main influencing factors were obtained by relationship fitting.Correlation analysis showed that the relationship between evapotranspiration and photosynthetically active radiation and water vapor pressure difference was quadratic polynomial,and evapotranspiration was linear with the net radiation flux.Furthermore,the univariate and bivariate functions were used to fit the relationship between evapotranspiration and its influencing factors.The results showed that the bivariate function was better than the univariate function.