摘要
本文用有压管道水击理论 ,解释了垂直饱和土柱出流通量随时间变化滞后于土柱顶部输入水头阶跃变化的原因 .当用Darcy定律分析土壤水流时 ,土柱出流通量随时间变化有一个跳跃间断 ;当用毛管模型分析土壤水流时 ,土柱出流通量随时间变化呈连续递增趋势 .在实际应用中 ,由于无法求得水击弹性波传播速度 ,可以参照土壤溶质传递函数分析方法 .实验结果和理论分析说明 ,阶跃输入下 ,土壤水分通量如同溶质通量一样 ,同样携带土壤系统对其作用的信息 ,表明用水分通量作传递函数分析信号是可行的 .
The hysteresis phenomenon,that the variation of soil water output flux at the bottom of a vertical saturated column is lagged behind the step changing input from the top,is explained according to the water hammer theory.An output jumping to final flux is found when Dacy's law is applied to the analysis of soil water flow.A monotonic increase of output flux is obtained based on the capillary tube model.It is recommended that the statistical equation should be applied to the determination of output flux,since the elastic wave propagation velocity is always unknown.Experimental result and theoretical analysis show that soil water carries information of soil system just as the transfer of dilute in soil,under the condition of step changing input.This indicates that water flux can be used as a signal for transfer function analysis.
出处
《水利学报》
EI
CSCD
北大核心
2001年第9期28-34,共7页
Journal of Hydraulic Engineering
基金
国家自然科学基金资助项目 ( 5 95 790 2 4)
关键词
均匀饱和土柱
水击
弹性波
土壤
水分
土柱
transfer function
step changing input
water hammer
elastic wave
