Effects of a low-permeability layer on unstable flow pattern and land-sourced solute transport in coastal aquifers

2021 ◽  
pp. 126397
Author(s):  
Jiaxu Zhang ◽  
Chunhui Lu ◽  
Chengji Shen ◽  
Chenming Zhang ◽  
Jun Kong ◽  
...  
Keyword(s):  
Solute Transport ◽  
Flow Pattern ◽  
Coastal Aquifers ◽  
Low Permeability ◽  
Unstable Flow

Simulation of solute transport across low-permeability barrier walls

2006 ◽  
Vol 85 (3-4) ◽  
pp. 247-270 ◽  
Author(s):  
Philip T. Harte ◽  
Leonard F. Konikow ◽  
George Z. Hornberger
Keyword(s):  
Solute Transport ◽  
Permeability Barrier ◽  
Low Permeability

scholarly journals Editorial of Special Issue “Advances in Groundwater Flow and Solute Transport: Pushing the Hidden Boundary”

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 457
Author(s):  
Hongbin Zhan ◽  
Quanrong Wang ◽  
Zhang Wen
Keyword(s):  
Numerical Methods ◽  
Groundwater Flow ◽  
Solute Transport ◽  
Vadose Zone ◽  
Regional Scale ◽  
Chemical Transport ◽  
Low Permeability ◽  
Special Issue ◽  
Flow And Transport ◽  
Wide Range

The theme of this special issue is to explore the new territories beyond conventional subsurface flow and transport theories. We have selected 12 articles in this special issue and these articles cover a wide range of problems including (1) Non-Fickian chemical transport in various environments; (2) Non-Darcian flow; (3) Flow and transport in low-permeability media; (4) Vadose zone process; (5) Regional scale groundwater flow and groundwater-surface interaction; (6) Innovative numerical methods. The major contributions of these papers are summarized in this editorial.

scholarly journals SOLUTE TRANSPORT MODELLING IN LOW-PERMEABILITY HOMOGENEOUS AND SATURATED SOIL MEDIA

2021 ◽  
Vol 36 (2) ◽  
pp. 25-32
Author(s):  
Muhammad Zaheer ◽  
Hadayat Ullah ◽  
Saad Ahmed Mashwani ◽  
Ehsan ul Haq ◽  
Syed Husnain Ali Shah ◽  
...  
Keyword(s):  
Solute Transport ◽  
Preferential Flow ◽  
Relative Concentration ◽  
Breakthrough Curves ◽  
Saturated Soil ◽  
Low Permeability ◽  
Transport Modelling ◽  
Variation Of Parameters ◽  
Solute Transport Modeling ◽  
Soil Media

Fickian and non-Fickian behaviors were often detected for contaminant transport activity owed to the preferential flow and heterogeneity of soil media. Therefore, using diverse methods to measure such composite solute transport in soil media has become an important research topic for solute transport modeling in soil media. In this article, the continuous-time random walk (CTRW) model was applied to illustrate the relative concentration of transport in low-permeability homogeneous and saturated soil media. The solute transport development was also demonstrated with the convection-dispersion equation (CDE) and Two Region Model (TRM) for comparison. CXTFIT 2.1 software was used for CDE and TRM, and CTRW Matlab Toolbox v.3.1 for the CTRW simulation of the breakthrough curve. It was found that higher values of determination coefficient (R2) and lower values of root mean square error (RMSE) concerning the best fits of CDE, TRM, and CTRW. It was found that in the comparison of CDE, TRM, and CTRW, we tend to use CTRW to describe the transport behavior well because there are prevailing Fickian and non-Fickian transport. The CTRW gives better fitting results to the breakthrough curves (BTCs) when β has an increasing pattern towards 2.00. In this study, the variation of parameters in three methods was investigated and results showed that the CTRW modeling approach is more effective to determine non-reactive contaminants concentration in low-permeability soil media at small depths.

scholarly journals Impact of Low- or High-Permeability Inclusion on Free Convection in a Porous Medium

Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-11
Author(s):  
Min Yan ◽  
Chunhui Lu ◽  
Jie Yang ◽  
Yifan Xie ◽  
Jian Luo
Keyword(s):  
Porous Media ◽  
Free Convection ◽  
Solute Transport ◽  
Large Scale ◽  
Effective Area ◽  
Source Zone ◽  
Sensitivity Analyses ◽  
Low Permeability ◽  
High Permeability ◽  
The Impact

Density-driven free convection in porous media is highly affected by large-scale heterogeneity, typical of which are low- or high-permeability inclusions imbedded in homogeneous porous media. In this research, we applied the modified Elder problem to investigate the impact of low- or high-permeability inclusions on the migration of a dense, unstable salt plume. Sensitivity analyses were conducted in terms of the permeability contrast, the effective area (the area of the inclusion beneath the source zone), and the distance of the inclusion from the source zone, all of which were found to play a significant role in controlling the total mass flux released from the source into the media. Results show that (1) a high-permeability inclusion has stronger effects than low-permeability inclusion, due to significantly unbalanced solute distributions caused by accelerated solute transport, (2) the inclusion with a larger effective area has more potential to influence free convection, (3) free convection is more sensitive to the low-/high-permeability inclusion vertically closer to the source zone, and (4) free convection is more susceptible to the low-permeability inclusion horizontally closer to the source zone. For high-permeability inclusions, the inclusion horizontally closer to the source zone influences the transport process more significantly at the early stage, and conversely, the inclusion far from the source zone has a later impact. The results obtained could offer significant implications for understanding unstable density-driven flow and solute transport in porous media with structured heterogeneity.

1215 PIV Measurement of Planar Abrupt Contraction Flow and the Appearance of Unstable Flow Pattern

2010 ◽  
Vol 2010.47 (0) ◽  
pp. 463-464
Author(s):  
Takahiro YAJIMA ◽  
Asahiko ANAZAWA ◽  
Nobuyuki FUJISAWA ◽  
Takayuki YAMAGATA
Keyword(s):  
Flow Pattern ◽  
Unstable Flow ◽  
Contraction Flow ◽  
Piv Measurement ◽  
Abrupt Contraction

Solute transport influenced by unstable flow in beach aquifers

2019 ◽  
Vol 125 ◽  
pp. 68-81 ◽  
Author(s):  
Chengji Shen ◽  
Chenming Zhang ◽  
Jun Kong ◽  
Pei Xin ◽  
Chunhui Lu ◽  
...  
Keyword(s):  
Solute Transport ◽  
Unstable Flow

scholarly journals An Experimental Study on Solute Transport in One-Dimensional Clay Soil Columns

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Muhammad Zaheer ◽  
Zhang Wen ◽  
Hongbin Zhan ◽  
Xiaolian Chen ◽  
Menggui Jin
Keyword(s):  
Solute Transport ◽  
Dispersion Equation ◽  
Transport Process ◽  
Breakthrough Curve ◽  
Small Scale ◽  
Low Permeability ◽  
Late Time ◽  
Time Behavior ◽  
One Dimensional ◽  
Advection Dispersion

Solute transport in low-permeability media such as clay has not been studied carefully up to present, and we are often unclear what the proper governing law is for describing the transport process in such media. In this study, we composed and analyzed the breakthrough curve (BTC) data and the development of leaching in one-dimensional solute transport experiments in low-permeability homogeneous and saturated media at small scale, to identify key parameters controlling the transport process. Sodium chloride (NaCl) was chosen to be the tracer. A number of tracer tests were conducted to inspect the transport process under different conditions. The observed velocity-time behavior for different columns indicated the decline of soil permeability when switching from tracer introducing to tracer flushing. The modeling approaches considered were the Advection-Dispersion Equation (ADE), Two-Region Model (TRM), Continuous Time Random Walk (CTRW), and Fractional Advection-Dispersion Equation (FADE). It was found that all the models can fit the transport process very well; however, ADE and TRM were somewhat unable to characterize the transport behavior in leaching. The CTRW and FADE models were better in capturing the full evaluation of tracer-breakthrough curve and late-time tailing in leaching.

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