不同时间尺度农田蒸散影响因子的通径分析

发布时间：2018-05-04 20:21

本文选题：通径分析 + 决策系数　；参考：《中国农业气象》2017年04期

【摘要】：基于2011-2015年冬小麦农田实测大型称重式蒸渗仪数据及农业气象观测数据,分析不同时间尺度农田蒸散量的分布特征,并利用通径分析方法对各时间尺度农田蒸散的影响因子进行辨识。结果表明:(1)冬小麦开花-乳熟期典型晴天小时尺度蒸散呈单峰变化,最大值为0.9~1.1mm·h~(-1),日累计蒸散量7.0~9.1mm·d~(-1);冬小麦全生育期多年平均蒸散总量为385.4mm,日平均蒸散量为2.6mm·d~(-1),最大日蒸散量11.0mm·d~(-1),变化趋势为前期较低、后期较高;在生育期尺度,播种-返青期的蒸散速率较小,多年平均值为1.1mm·d~(-1),返青后,农田蒸散速率加快,多年平均值为4.2mm·d~(-1)。(2)不同时间尺度蒸散变化的影响因子主要包括净辐射(Rn)、饱和水汽压差(VPD)、0cm地温(T_(g0))、20cm土壤水分(SW20)。在小时尺度,VPD对典型晴天蒸散变化的直接作用最大,其次为Rn,T_(g0)通过Rn路径对EThourly变化产生间接影响,对蒸散的综合决定能力排序依次为VPDT_(g0)Rn;在日尺度,Rn作为最关键的影响因子,对蒸散的直接影响最大,VPD对蒸散的间接影响最大,VPD、T_(g0)主要通过Rn路径间接影响蒸散,SW20再通过T_(g0)路径间接影响蒸散且为负效应,各因子决策系数排序依次为RnVPDT_(g0)SW20;在生育期尺度,T_(g0)和Rn是驱动蒸散变化的最主要因子并起直接影响作用,决策系数表明T_(g0)对蒸散变化的促进作用比Rn明显。
[Abstract]:Based on the data of measured large weighing lysimeter and agrometeorological observation data of 2011-2015 years of winter wheat field, the distribution characteristics of the evapotranspiration in different time scales were analyzed, and the influence factors of the evapotranspiration in each time scale were identified by means of path analysis. The results showed that: (1) the typical sunny hour ruler of the flowering and milk ripening period of Winter Wheat The maximum evapotranspiration is 0.9~1.1mm. H~ (-1), and the daily evapotranspiration is 7.0~9.1mm. D~ (-1). The average annual evapotranspiration of winter wheat is 385.4mm, the average daily evapotranspiration is 2.6mm. D~ (-1), the maximum daily evapotranspiration is 11.0mm. The trend is lower in the early stage and higher in the later period. The rate of dispersion is small, the average annual value is 1.1mm. D~ (-1). After returning to green, the evapotranspiration rate of farmland is quicker, the average value is 4.2mm. D~ (-1). (2) the influence factors of the variation of evapotranspiration in different time scales mainly include net radiation (Rn), saturated vapor pressure difference (VPD), 0cm ground temperature (T_ (G0)) and 20cm soil moisture. The direct effect of transformation is the largest, followed by Rn, T_ (G0) has an indirect effect on the change of EThourly through the Rn path. The order of the comprehensive determination of evapotranspiration is VPDT_ (G0) Rn in turn; in the daily scale, Rn is the most critical influence factor, and the direct influence on the evapotranspiration is the greatest. VPD has the greatest indirect effect on the evapotranspiration, VPD, and T_ mainly through the path indirect. The influence of evapotranspiration, SW20 and T_ (G0) path indirectly influenced the transpiration and negative effect. The order of factor decision coefficients of each factor was RnVPDT_ (G0) SW20, T_ (G0) and Rn were the main factors driving the change of evapotranspiration, and the decision coefficient showed that T_ (G0) promoted the Evapotranspiration to be more obvious than that of Rn.

【作者单位】：南京信息工程大学气象灾害教育部重点实验室/江苏省农业气象重点实验室/气象灾害预报预警与评估协同创新中心;中国科学院大学;中国科学院地理科学与资源研究所生态系统网络观测与建模重点实验室;
【基金】：公益性行业(气象)科研专项(GYHY201506001;GYHY201306046) 气象灾害教育部重点实验室(南京信息工程大学)开放课题(KLME1415) 江苏省农业气象重点实验室项目(KYQ1404)
【分类号】：S512.11;S161.4

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