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On the importance of hysteresis and heterogeneity in the numerical simulation of unsaturated flow

Nakagawa, Kei; Saito, M. and Berndtsson, Ronny LU (2012) In Hydrological Research Letters 6. p.59-64
Abstract
Soil hydraulic properties in field scale porous media are distributed with large spatial heterogeneity. Thus, detailed understanding of micro-physical properties leading to macro-scale heterogeneity is important for generalizing purposes in modeling. Hysteretic water retention properties greatly affect solute transport under unsaturated condition. In this study, laboratory infiltration experiments were carried out to investigate the importance of hysteresis in numerical modeling of water flow under heterogeneous distribution of hydraulic conductivity. Soil water content was observed by time domain reflectometry using small printed circuit board probes (PCBP). The PCBP observations were compared to results from numerical simulations... (More)
Soil hydraulic properties in field scale porous media are distributed with large spatial heterogeneity. Thus, detailed understanding of micro-physical properties leading to macro-scale heterogeneity is important for generalizing purposes in modeling. Hysteretic water retention properties greatly affect solute transport under unsaturated condition. In this study, laboratory infiltration experiments were carried out to investigate the importance of hysteresis in numerical modeling of water flow under heterogeneous distribution of hydraulic conductivity. Soil water content was observed by time domain reflectometry using small printed circuit board probes (PCBP). The PCBP observations were compared to results from numerical simulations involving saturated-unsaturated seepage analysis and two-phase flow with/without hysteresis effects. Observations were compared to both uniform and heterogeneous parameter modeling. Differences between unsaturated-saturated and two-phase flow were quite small in the numerical results for soil water content. The uniform parameter model, however, could not properly reproduce experimental water content change. The numerical results of water content change including hysteresis matched better observations for the unsaturated-saturated and two-phase flow cases. Results displayed that it is important to take heterogeneity and hysteresis into consideration in the numerical modeling in both two-phase and saturated-unsaturated flow analysis. (Less)
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in
Hydrological Research Letters
volume
6
pages
59 - 64
ISSN
1882-3416
language
English
LU publication?
yes
id
a65e79f6-c05e-4e9a-9e1c-233df17f01d0 (old id 3327911)
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http://www.hrljournal.org/archives/1083
date added to LUP
2013-01-04 14:07:58
date last changed
2016-04-16 06:29:53
@article{a65e79f6-c05e-4e9a-9e1c-233df17f01d0,
  abstract     = {Soil hydraulic properties in field scale porous media are distributed with large spatial heterogeneity. Thus, detailed understanding of micro-physical properties leading to macro-scale heterogeneity is important for generalizing purposes in modeling. Hysteretic water retention properties greatly affect solute transport under unsaturated condition. In this study, laboratory infiltration experiments were carried out to investigate the importance of hysteresis in numerical modeling of water flow under heterogeneous distribution of hydraulic conductivity. Soil water content was observed by time domain reflectometry using small printed circuit board probes (PCBP). The PCBP observations were compared to results from numerical simulations involving saturated-unsaturated seepage analysis and two-phase flow with/without hysteresis effects. Observations were compared to both uniform and heterogeneous parameter modeling. Differences between unsaturated-saturated and two-phase flow were quite small in the numerical results for soil water content. The uniform parameter model, however, could not properly reproduce experimental water content change. The numerical results of water content change including hysteresis matched better observations for the unsaturated-saturated and two-phase flow cases. Results displayed that it is important to take heterogeneity and hysteresis into consideration in the numerical modeling in both two-phase and saturated-unsaturated flow analysis.},
  author       = {Nakagawa, Kei and Saito, M. and Berndtsson, Ronny},
  issn         = {1882-3416},
  language     = {eng},
  pages        = {59--64},
  series       = {Hydrological Research Letters},
  title        = {On the importance of hysteresis and heterogeneity in the numerical simulation of unsaturated flow},
  volume       = {6},
  year         = {2012},
}