Hydraulic Conductivity Tab

Return to chapter overviewReturn to Top

 

 

 

 

 

SVFlux

 

 

Hydraulic Conductivity Typical Ranges

 Typical ranges for values of hydraulic conductivity for various materials may be seen in the following chart.

 

 Hydraulic Conductivity chart showing range of hydraulic conductivity (Reference: Holtz and Kovacs. An Introduction to Geotechnical Engineering, pp 210)

 

Saturated Hydraulic Conductivity

The saturated hydraulic conductivity, ksat value is the hydraulic conductivity of the material in the x-direction when the pressure is zero. Press the Units button to display the specified ksat in metric and imperial units for each time unit option. This dialog is strictly for reference.

 

NOTE:

 

SVFLUX requires that every material have a ksat value. The model will remain unsolvable until each material used in the model has a ksat value defined.
 

 

Unsaturated Hydraulic Conductivity

There are 9 mutually exclusive options available for the unsaturated hydraulic conductivity. The Modified Campbell, van Genuchten and Mualem, Brooks & Corey, Gardner, and Leong and Rahardjo hydraulic conductivity curve estimation methods are discussed in the Unsaturated Hydraulic Conductivity Estimation Methods section. Press the button to the right of each option to open its estimation dialog. If estimation data is present the button will display a blue Y while it will be a red X if there is no data entered.

 

The estimation methods are provided to allow a smooth representation of the unsaturated hydraulic conductivity curve. SVFLUX allows the use of laboratory data but it should be noted that linear interpolation is used to determine points between measured laboratory points. This interpolation may not be ideal under some circumstances.

 

If the None option is selected the ksat value will be used. If the Laboratory Data option is selected the data entered in the Laboratory Data section of the tab will be used.

 

Anisotropy

Materials in the field are often stratified and as a result, their properties may vary directionally. This directional variation may be simulated in SVFLUX through the anisotropy parameters. In particular, k-ratios may be used to account for variation in the x, y, and z directions while the Anisotropy Angles may be used to specify an inclination of the variation of parameters.

 

NOTE:

 

SVFLUX will expand the partial differential equation to solve anisotropy. This will result in a longer solution time. If anisotropy is not required for model solution ensure both alpha and beta angles are set to 0.
 

 

k-ratios

The ky-ratio is a number describing the ability of water to flow in the y-direction with respect to the x-direction, or ksat value. For example, the ky-ratio is entered as .5 and the ksat for the material is 10e-5 m/s. This would mean the material would have a conductivity in the y-direction of, ky = .5 * ksat, or ky = .5 * 10e-5 m/s. ky would therefore be 5e-5 m/s. The kz-ratio is the number describing the ability of water to flow in the z-direction with respect to the x-direction.

 

2D Anisotropy Angle

Alpha, α: This is the angle at which the material stratum is inclined from the horizontal measured from the positive X-axis.

 

3D Anisotropy Angles

Alpha, α: This is the angle at which the material stratum is inclined from the from the positive X-axis on the XY plane.

Beta, β: This is the angle at which the material stratum is inclined from the from the positive X-axis on the XZ plane.