文章摘要
向 龙,余钟波,Jarai Mon,Li Chen.大空隙流变化对溶质运移的影响试验研究[J].水利学报,2010,41(8):
大空隙流变化对溶质运移的影响试验研究
The quantificational experiment on the movement of macro-pore flow and its impacts on solute movement
  
DOI：
中文关键词: 大空隙流  特征半径指数  有效孔隙度  溶质运移  基模势
英文关键词: macro-pore flow  representative pore radius  EHP  solute transport  matric potential
基金项目:
作者单位
向 龙 1. 河海大学 水文学与水资源及水利工程国家重点实验室，江苏 南京 210098；2. 河海大学 水文与水资源学院，江苏 南京 210098；3. Geoscience department of UNLV，Las vegas，USA 89119 
余钟波 1. 河海大学 水文学与水资源及水利工程国家重点实验室，江苏 南京 210098；2. 河海大学 水文与水资源学院，江苏 南京 210098；3. Geoscience department of UNLV，Las vegas，USA 89119 
Jarai Mon Geoscience department of UNLV，Las vegas，USA 89119 
Li Chen Desert research institution， las vegas，USA 89119 
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中文摘要:
      本试验设计3个来自Armagosa沙漠研究站的相似原状土柱在基模势为0、-2、-5、-10cm水头状态下，分别进行保守溶质置换试验，获取12条溶质穿透曲线。改进的特征半径指数用于定量分离各基模势区间，并计算有效水力传导孔隙度描述大空隙流的变化过程。同时，基于对流扩散方程 （CDE） 的确定性双区模型用于拟合各个状态下溶质运动的特征参数。试验结果显示，改进后的特征半径指数和大孔隙有效传导空隙度能很好定量大空隙流变化。在大空隙流发生时，溶质运移主要受到大空隙流对流作用影响，机械弥散作用变化不大。随着大空隙流的衰减，大空隙流与基质流的侧向交换过程逐渐成为溶质穿透过程的主要影响因素。大空隙流发生与基模势的关系有利于进一步分离研究土壤非均质流与溶质交互过程。
英文摘要:
      To focus on analyzing and evaluating the macro-pore flow affecting the transport of refilledcontaminants in Armagosa desert soil，the quantification research between soil potential and macropore flow should be understood，and distinguish the influence of preferential flow affecting on solute transport in porous media. Three undisturbed soil columns from Armagosa Desert Research Site （ADRS） were designed for conducting Br displace experiments in laboratory at various matric heads， such as 0，-2，-5，and -10cm as 12 breakthrough curves （BTC） were obtained. A modified representative mean pore radius（MRMPR） was applied to separate the effective hydraulic porosity （EHP） among different matric potential ranges. The deterministic two-region model based on convection-dispersion equation （CDE） was utilized to simulate solute transport at different steady states. The results showed that MRMPR and EHP can be used to quantitatively analyze the change of macro-pore flow and to estimate the generation of macro-pore flow with the help of hydraulic contributions. When macro-pore flow occurred，the solute transport was mainly controlled by water convection while the mechanical dispersivity changed a little. With the decrease of macro-pore flow，the lateral exchange between matric flow and macro-pore flow became crucial factors influencing the solute transport. The relationship between macro-pore flow and matric potential was in favor of investigating mutual processes among heterogeneous flow in soil.
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