Open AccessFlow Focusing in Unsaturated Fracture Networks: A Numerical Investigation
Author(s) -
Zhang Keni,
Wu YuShu,
Bodvarsson G. S.,
Liu HuiHai
Publication year - 2004
Publication title -
vadose zone journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.036
H-Index - 81
ISSN - 1539-1663
DOI - 10.2136/vzj2004.0624
Subject(s) - flow (mathematics) , permeability (electromagnetism) , geology , geotechnical engineering , fracture (geology) , vadose zone , mechanics , matrix (chemical analysis) , computer simulation , scale (ratio) , flow network , petrology , materials science , mathematics , chemistry , physics , composite material , mathematical optimization , quantum mechanics , membrane , groundwater , biochemistry
A numerical modeling study is presented to investigate flow–focusing phenomena in a large‐scale fracture network, constructed using field data collected from the unsaturated zone of Yucca Mountain, Nevada, the proposed repository site for high‐level nuclear waste. The two‐dimensional fracture network for an area of 100 by 150 m contains more than 20000 fractures. Steady state unsaturated flow in the fracture network is investigated for different boundary conditions and rock properties. Simulation results indicate that flow paths are generally vertical, and that horizontal fractures mainly provide pathways between neighboring vertical paths. In addition to fracture properties, flow–focusing phenomena are also affected by rock–matrix permeability, with lower matrix permeability leading to a high degree of flow focusing. The simulation results further indicate that the average spacing between flow paths in a layered system tends to increase and flow tends to become more focused, with depth.