The sap flow velocity and the micro-meteorological environment of Sophora japonica f.pendula were measured from Aug.to Oct.2006 with sap flow gauge based on heat balance principle and auto-weather station in Ludong Un...The sap flow velocity and the micro-meteorological environment of Sophora japonica f.pendula were measured from Aug.to Oct.2006 with sap flow gauge based on heat balance principle and auto-weather station in Ludong University.The time lag effect of sap flow compared to meteorological factors was analyzed,and the regressive analysis between comprehensive affecting factor put forward by principal component analysis and sap flow was conducted.The time lag effect analysis results showed that the sap flow lag effect existed compared to total solar radiation,wind speed and photosynthetically active radiation,and the lag time was 10 min,20 min and 10 min,respectively.The time lag effect was the reason of water storage adjustment of leaves,branches and trunks.The sap flow lag time to total solar radiation and photosynthetically active radiation was shorter than wind,because solar radiation affected tree transpiration directly,and the wind affected tree transpiration through affecting boundary resistance of leaves.In the case sap flow time lag considered or not,the determination coefficients between comprehensive meteorological affecting factor and sap flow were 0.830 and 0.944,respectively,and the determination coefficient ascending 13.735% because of lag effect considered.In conclusion,the fitted precision would be improved with the time lag effect of trunk sap flow compared to micro-meteorological factors considered.展开更多
该文利用单环入渗的概化解,对不同土地利用方式下烟台棕壤土的饱和导水率进行了研究,同时分析了不同单环直径对求解饱和导水率产生的影响。研究结果表明:草地、裸地和道路的入渗速率、累积入渗量和饱和导水率呈现依次降低的变化趋势,利...该文利用单环入渗的概化解,对不同土地利用方式下烟台棕壤土的饱和导水率进行了研究,同时分析了不同单环直径对求解饱和导水率产生的影响。研究结果表明:草地、裸地和道路的入渗速率、累积入渗量和饱和导水率呈现依次降低的变化趋势,利用直径为20、30和45 cm的入渗环得到的饱和导水率具有明显的差异性。根据求解的饱和导水率计算的累积入渗量非常接近实测值,整体相对误差很小,草地、裸地和道路,在5、7和40 m in后浮动在5%以内;在15、43和55 m in后变化幅度小于1%。20、30和45 cm入渗环累积入渗量计算值的相对误差初始阶段波动较大,随后逐渐趋于平稳。展开更多
文摘The sap flow velocity and the micro-meteorological environment of Sophora japonica f.pendula were measured from Aug.to Oct.2006 with sap flow gauge based on heat balance principle and auto-weather station in Ludong University.The time lag effect of sap flow compared to meteorological factors was analyzed,and the regressive analysis between comprehensive affecting factor put forward by principal component analysis and sap flow was conducted.The time lag effect analysis results showed that the sap flow lag effect existed compared to total solar radiation,wind speed and photosynthetically active radiation,and the lag time was 10 min,20 min and 10 min,respectively.The time lag effect was the reason of water storage adjustment of leaves,branches and trunks.The sap flow lag time to total solar radiation and photosynthetically active radiation was shorter than wind,because solar radiation affected tree transpiration directly,and the wind affected tree transpiration through affecting boundary resistance of leaves.In the case sap flow time lag considered or not,the determination coefficients between comprehensive meteorological affecting factor and sap flow were 0.830 and 0.944,respectively,and the determination coefficient ascending 13.735% because of lag effect considered.In conclusion,the fitted precision would be improved with the time lag effect of trunk sap flow compared to micro-meteorological factors considered.
文摘该文利用单环入渗的概化解,对不同土地利用方式下烟台棕壤土的饱和导水率进行了研究,同时分析了不同单环直径对求解饱和导水率产生的影响。研究结果表明:草地、裸地和道路的入渗速率、累积入渗量和饱和导水率呈现依次降低的变化趋势,利用直径为20、30和45 cm的入渗环得到的饱和导水率具有明显的差异性。根据求解的饱和导水率计算的累积入渗量非常接近实测值,整体相对误差很小,草地、裸地和道路,在5、7和40 m in后浮动在5%以内;在15、43和55 m in后变化幅度小于1%。20、30和45 cm入渗环累积入渗量计算值的相对误差初始阶段波动较大,随后逐渐趋于平稳。
