Simulation of vadose zone flow processes via inverse modeling of modified multistep outflow for fine‐grained soils

2020 ◽  
Vol 84 (5) ◽  
pp. 1592-1605
Author(s):  
Amir Bahrami ◽  
Fateme Aghamir
Keyword(s):  
Vadose Zone ◽  
Inverse Modeling ◽  
Fine Grained ◽  
Flow Processes ◽  
Multistep Outflow

scholarly journals Inverse modeling of vadose zone flow processes using squared ε-insensitivity loss function

2010 ◽  
Vol 58 (3) ◽  
Author(s):  
Navin Twarakavi ◽  
Hirotaka Saito ◽  
Jirka Šimůnek ◽  
M. Van Genuchten
Keyword(s):  
Loss Function ◽  
Vadose Zone ◽  
Inverse Modeling ◽  
Flow Processes

Fluid migration in the vadose zone from 3-D inversion of resistivity monitoring data

Geophysics ◽  
1998 ◽  
Vol 63 (1) ◽  
pp. 41-51 ◽  
Author(s):  
Stephen Park
Keyword(s):  
Vadose Zone ◽  
Fluid Migration ◽  
Inversion Process ◽  
Resistivity Tomography ◽  
Capillary Action ◽  
Fine Grained ◽  
Fluid Concentration ◽  
Resistivity Inversion ◽  
Systematic Development ◽  
Precipitation Events

The movement of a small plume of fresh water through the vadose zone was monitored using surface resistivity tomography and pole‐pole potential measurements. Sets of potential measurements on a square grid at several times throughout the experiment show gradual, progressive, and systematic development of low‐resistivity zones that are inferred to be loci of fluid concentration. A procedure for inverting percentage changes in potentials is developed here and used to map maximum potential changes of 13% into resistivity decreases of up to 40% through 3-D resistivity inversion. The resulting patterns are complex, with both resistivity increases and decreases needed to match the observed data. The resistivity reductions show a spatial connection to the plume’s source and are suggestive of the fluid migration. Resistivity increases generally appear to form rims surrounding the decreases and may be artifacts of the inversion process. However, some isolated increases in the surface layer may be caused by evaporation of fluid from previous precipitation events. Interpretation of the complex patterns may limit the usefulness of this method for monitoring fluid migration. Nonetheless, the resulting pattern of resistivity reductions may show details of fluid migration that are unavailable with more conventional monitoring techniques. In this experiment, comparison of the volume with reduced resistivity with the volume of injected water predicts only a 0.5% increase in saturated porosity, demonstrating that fluid flow in the vadose zone was most likely controlled by the distribution of fine‐grained clays and silts and occurred by capillary action.

Vadose Zone, Part I : Characterization and Flow Processes

2003 ◽  
Author(s):  
Yoram Rubin
Keyword(s):  
Porous Media ◽  
Water Flow ◽  
Governing Equation ◽  
Vadose Zone ◽  
Stochastic Analysis ◽  
Transport Processes ◽  
Richards Equation ◽  
Saturated Porous Media ◽  
Flow And Transport ◽  
Flow Processes

Many of the principles guiding stochastic analysis of flow and transport processes in the vadose zone are those which we also employ in the saturated zone, and which we have explored in earlier chapters. However, there are important considerations and simplifications to be made, given the nature of the flow and of the governing equations, which we explore here and in chapter 12. The governing equation for water flow in variably saturated porous media at the smallest scale where Darcy’s law is applicable (i.e., no need for upscaling of parameters) is Richards’ equation (cf. Yeh, 1998)

scholarly journals Planning MAR Schemes Using Physical Models: Comparison of Laboratory and Field Experiments

2019 ◽  
Vol 9 (18) ◽  
pp. 3652
Author(s):  
Jana Sallwey ◽  
Felix Barquero ◽  
Thomas Fichtner ◽  
Catalin Stefan
Keyword(s):  
Vadose Zone ◽  
Laboratory Experiments ◽  
Field Experiments ◽  
Managed Aquifer Recharge ◽  
Physical Models ◽  
Aquifer Recharge ◽  
Operational Parameters ◽  
Flow Processes ◽  
Models Comparison ◽  
Other Regarding

Infiltration experiments in the context of managed aquifer recharge (MAR) are often conducted to assess the processes influencing the operation of full-scale MAR schemes. For this, physical models such as laboratory experiments and, less often, field experiments are used to determine process specifics or operational parameters. Due to several assumptions, scale-related limitations, and differing boundary conditions, the upscaling of results from the physical models is not straightforward. Investigations often lead to over- or underestimations of flow processes that constrain the translation of results to field-like conditions. To understand the restrictions and potential of different physical models for MAR assessment, surface infiltration experiments in different scales and dimensions, which maintained the same operational parameters, were conducted. The results from the different setups were compared against each other regarding the reproduction water flow in the vadose zone and the influence of parameters such as soil type and climate. Results show that mostly qualitative statements can be made, whereas quantitative analysis through laboratory experiments is limited.

scholarly journals Inverse modeling of large-scale spatially distributed vadose zone properties using global optimization

2004 ◽  
Vol 40 (6) ◽  
Author(s):  
Jasper A. Vrugt ◽  
Gerrit Schoups ◽  
Jan W. Hopmans ◽  
Chuck Young ◽  
Wesley W. Wallender ◽  
...  
Keyword(s):  
Global Optimization ◽  
Vadose Zone ◽  
Inverse Modeling ◽  
Large Scale ◽  
Spatially Distributed
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