基于通径分析法的漳河灌区参考作物蒸发蒸腾量变化成因研究

Study of the Causes of Reference Evapotranspiration in Zhanghe Irrigation Area Based on Path Analysis Method

选取漳河灌区1974—2014年逐日气象数据,运用Excel软件和SPSS 24.0软件对4项主控因子和参考作物蒸发蒸腾量(ET0)进行趋势分析和通径分析。结果表明,多年平均气温(T)和平均相对湿度(RH)均呈显著性上升趋势,多年日照时数(n)和ET0呈不显著性下降趋势,多年平均风速(u)呈显著性下降趋势。日平均相对湿度(RH)与ET0呈负相关,其余主控因子与ET0均为正相关,日照时数(n)和平均风速(u)的相关性最高。日照时数(n)的决定系数、对回归方程R2的贡献和对ET0的直接效果均为各主控因子中最大,是影响ET0的决策变量。

Daily meteorological data of Zhanghe irrigation area from 1974 to 2014 were collected,the trend and path analysis of four main control factors and ET 0 were carried out by Excel and SPSS 24.0.The results show that:the annual average temperature and average relative humidity were significantly increased,sunshine hours and ET 0 showed no significant decline,and the annual mean wind speed presented a significant downward trend.The correlation between sunshine hours and average wind speed was the highest,and the daily average relative humidity was negatively correlated with ET 0,meanwhile the remaining main control factors were positively correlated with ET 0.Sunshine hours’s decision coefficient,its contribution to the regression equation of R 2 and the rate of the direct effect of ET 0 were the biggest,therefore,sunshine hours are the decision variable affecting the ET 0.