Search found 4983 matches

by Jirka
Sun Nov 23, 2003 2:50 am
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: Flux and velocity
Replies: 1
Views: 2971

Mazen The node flux Q (V/T) and the node velocity v(L/T) in the boundary.out must match. v is calculated as Q divided by width associated with the particular boundary node. The boundary width is written in the boundary.in input file (calculated in the interface). Velocities in the boundary.out file ...
by Jirka
Tue Nov 18, 2003 8:54 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: hCritS
Replies: 3
Views: 3834

Jure,

For that purpose you can use either variable or constant pressure head BC.

Jirka
by Jirka
Fri Nov 14, 2003 4:43 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: hCritS
Replies: 3
Views: 3834

Jure, In Hydrus-2D the hCritS variable is set as default equal to zero and the surface runoff starts immediately after ponding is reached. You can not have positive pressure heads at the soil surface when using atmospheric BC. Hydrus-2D does not consider accumulation of water on the surface. Things ...
by Jirka
Fri Nov 07, 2003 11:20 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: High Pressure head result
Replies: 4
Views: 4831

Zal,

I do not think that your question is clear enough to me to answer.

Jirka
by Jirka
Fri Nov 07, 2003 10:01 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: Deep drainage
Replies: 4
Views: 4830

I do not think so. If you have your transport domain in different positions (in terms of the z coordinate) then you can just adjust your GWL0L parameter to adjust the function. Your solution does not realy depends on coordinates (z), only on initial and boundary conditions.

J.
by Jirka
Fri Nov 07, 2003 9:58 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: Scaling factors
Replies: 19
Views: 15224

Sevim, Numbering of nodes in the structured mesh: It is very straightforward. The first node is the left bottom node. Then I continue to the right (Nx – number of nodes horizontally), then up all the way to the surface (Nz – number of nodes vertically), all the way to the left, and then down. Once a...
by Jirka
Fri Nov 07, 2003 9:49 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: inverse solution of ring infiltrometer test
Replies: 3
Views: 4124

Jure, It is well known that infiltration curve can be used to estimate maximum two parameters. Cumulative or actual infiltration curve thus does not contain enough information to estimate more parameters. Therefore, this information is usually used to simply estimate Ks and sorptivity from Phillip a...
by Jirka
Fri Nov 07, 2003 9:45 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: Effect of hCritA on Underlying Soil
Replies: 3
Views: 4070

Sophia,

If you want to initiate drying of the underlaying clay, you need to use fine textured material at the surface. Once you have course textured sand or gravel at the surface, underlying clay should not get dry due to evaporation.

Jirka
by Jirka
Fri Nov 07, 2003 9:42 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: Deep drainage
Replies: 4
Views: 4830

I guess the easiest way to understand this is to see the code. There is a function real function Fqh(GWL,Aqh,Bqh) Fqh=-Aqh*exp(Bqh*abs(GWL)) return end that calculates the flux. It is called as follows: Q(n)=-Width(i)*Fqh(hNew(n)-GWL0L,Aqh,Bqh) where hnew is the pressure in a particular node, GWL0L,...
by Jirka
Fri Oct 31, 2003 4:22 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: High Pressure head result
Replies: 4
Views: 4831

Zal, Free drainage boundary condition can not be assigned on sides of the transport domain. It can be assinged only at the bottom. Free drainage BC is actually a unit gradient BC, which means that flux out of the domain is equal to the conductivity for an actual pressure head in a particular boundar...
by Jirka
Thu Oct 30, 2003 4:38 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: Scaling factors
Replies: 19
Views: 15224

Sevim, The reason why we number first the nodes at the boundary and then the internal nodes is due to the graphical interface. The graphical interface treats these nodes differently than internal nodes (such as displaying only boundary nodes, allowing users to specify boundary conditions, etc.). Whe...
by Jirka
Thu Oct 30, 2003 4:31 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: Huge output files
Replies: 3
Views: 4004

Klaus, There is no reason whatsoever, why the code would take a different number of time steps under different operation systems. The computational code is written in Fortran, which as standard language, fully transferable from one OS to another. If you do not want these huge output files, when you ...
by Jirka
Wed Oct 29, 2003 5:54 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: Non-Vertical Axis of Symmetry?
Replies: 1
Views: 2699

Sophia,

No, it is not. The axis of symmetry must coincide with the direction of gravity. If it does not, then the problem is not axisymmetrical.

Jirka
by Jirka
Wed Oct 29, 2003 5:52 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: Effect of hCritA on Underlying Soil
Replies: 3
Views: 4070

Sophia, If the surface layer reaches the residual saturation and thus negligible hydraulic conductivity, the clay below the surface layer will never get dry. That’s the quality of the layered profile that is being very often used in engineering. One spreads a course sand or gravel at the soil surfac...
by Jirka
Wed Oct 29, 2003 5:37 pm
Forum: Hydrus 2D (old version 1996 - 2005)
Topic: Scaling factors
Replies: 19
Views: 15224

The release of the latest update has been delayed since Eileen and Rien insisted that we have to first improve our security features. It could be out in a week or two.

Jirka