Macroscopic relationship for preferential flow in the vadose zone:Theory and validation

作     者：LIU HuiHai1 & ZHANG RenDuo2 1 Earth Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 947200, USA 2 School of Environmental Science and Engineering, Sun Yat-sen University, Guangzhou 510275, China 

作者机构：Earth Science Division Lawrence Berkeley National Laboratory Berkeley CA 947200 USA School of Environmental Science and Engineering Sun Yat-sen University Guangzhou 510275 China 

出 版 物：《Science China(Technological Sciences)》 (中国科学（技术科学英文版）)

年 卷 期：2009年第52卷第11期

页      面：3264-3269页

核心收录：

学科分类：08[工学] 0815[工学-水利工程] 

主　　题：preferential flow constitutive relations vadose zone hydrology 

摘      要：Preferential flow commonly observed in unsaturated soils allows rapid movement of solute from the ground surface or vadose zone to the groundwater, bypassing a significant volume of unsaturated soil and increasing the risk of groundwater contamination. A variety of evidence indicates that complex preferential flow patterns observed from fields are fractals. This paper discusses a macroscopic relationship for modeling preferential flow in the vadose zone. Conceptually, the flow domain can be divided into active and inactive regions. Flow occurs preferentially in the active region (characterized by fractals), and inactive region is simply bypassed. The portion of the active region was found to be a power function of saturation. The validity of this macroscopic relationship is demonstrated by its consistency with field observations and the related numerical experiments.