Search found 4651 matches

by Jirka
Wed Apr 24, 2019 12:48 am
Forum: HYDRUS (2D/3D)
Topic: Solute Boundary Condition Equations
Replies: 1
Views: 4

Re: Solute Boundary Condition Equations

That depends on the numerical scheme. For the explicit scheme, it is the concentration at the old time, for the fully implicit scheme at the new time, and for Crank-Nicholson half of both. J.
by Jirka
Fri Apr 19, 2019 7:53 pm
Forum: Hydrus 1D
Topic: Thermal conductivity in output file
Replies: 1
Views: 11

Re: Thermal conductivity in output file

We do not print thermal conductivity in the Nod_inf.out file, as it is quite simple to calculate it from the water content and eq. 4.8. We print various thermal conductivities (isothermal, thermal, liquid, gas) into the Nod_inf_V.out when you consider vapor flow (see Table 13.13 of the Manual). J.
by Jirka
Fri Apr 19, 2019 2:29 am
Forum: Hydrus 1D
Topic: How does Hydrus calculate Fitted flux in inverse solution?
Replies: 4
Views: 24

Re: How does Hydrus calculate Fitted flux in inverse solution?

Only boundary fluxes (top and/or bottom fluxes) can be included in the objective function of the inverse solution. These are calculated by integrating actual (top and/or bottom) fluxes over time. J.
by Jirka
Thu Apr 18, 2019 3:33 pm
Forum: Hydrus 1D
Topic: W-Volume and hCritA
Replies: 2
Views: 18

Re: W-Volume and hCritA

W-Volume is defined in the Manual as "Volume of water in the entire flow domain or in a specified subregion [L]" and how it is calculated is give by eq. 7.17.. That would be the figure on the right. hCritA specifies the minimum allowed surface pressure head (defined from equilibrium conditions betwe...
by Jirka
Tue Apr 16, 2019 3:10 pm
Forum: Hydrus 1D
Topic: About spatial discretization
Replies: 2
Views: 22

Re: About spatial discretization

I suggest that you look at the following webpage: https://www.pc-progress.com/en/Default. ... filtration. Here I did the sensitivity analysis of simulation results for infiltration as a function of soil texture, initial saturation, spatial discretization, etc. J.
by Jirka
Tue Apr 16, 2019 3:04 pm
Forum: Hydrus 1D
Topic: Solute Transport Hydrus 1D
Replies: 4
Views: 29

Re: Solute Transport Hydrus 1D

I do not have them. You would have to contact Dr. Li Yong directly. J.
by Jirka
Mon Apr 15, 2019 4:24 pm
Forum: Hydrus 1D
Topic: Solute Transport Hydrus 1D
Replies: 4
Views: 29

Re: Solute Transport Hydrus 1D

1. Correct. If the basal fertilizer is in the soil profile at the beginning of the simulations, it should be specified as an initial condition. If it is applied during the simulation time, it should be specified as a boundary condition (cTop). 2. Correct. The concentration of solute can be obtained ...
by Jirka
Thu Apr 11, 2019 7:33 pm
Forum: HYDRUS (2D/3D)
Topic: Modeling ponding, infiltration
Replies: 3
Views: 45

Re: Modeling ponding, infiltration

I think you misunderstand this option. We have these two options, which are related to time-variable head/flux BCs and atmospheric BCs: 1. "Switch the boundary condition from Time-Variable Pressure head to" "Atmospheric BC when the specified nodal pressure head is negative". This is meant for condit...
by Jirka
Thu Apr 11, 2019 4:28 pm
Forum: HYDRUS (2D/3D)
Topic: Modeling ponding, infiltration
Replies: 3
Views: 45

Re: Modeling ponding, infiltration

The definition of this problem makes little physical sense to me. Why would you expect to have any atmospheric fluxes, when you have no atmospheric boundary conditions specified anywhere on the domain boundary? Also, your initial conditions make little physical sense. If "groundwater is far below" t...
by Jirka
Thu Apr 11, 2019 3:15 am
Forum: HYDRUS (2D/3D)
Topic: Modeling an infiltration well
Replies: 2
Views: 42

Re: Modeling an infiltration well

There are a couple of problems with your project. The main one is that you cannot have negative x coordinates in the axisymmetrical problem. The center of symmetry is x=0. You also likely want to have finer discretization around the well.

J.
Eliane Simetrico.rar
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by Jirka
Thu Apr 11, 2019 2:43 am
Forum: Hydrus 1D
Topic: Water Transport
Replies: 2
Views: 47

Re: Water Transport

These are your soil hydraulic parameters (Qr [-] Qs [-] Alpha [1/cm] n [-] Ks [cm/hour] l [-]). These are not your initial conditions. You need to still specify the initial condition. J.
by Jirka
Wed Apr 10, 2019 6:21 pm
Forum: HYDRUS (2D/3D)
Topic: Stochastic distribution of SF
Replies: 1
Views: 23

Re: Stochastic distribution of SF

The stochastic scaling factors are generated by a routine in the HYDRUS GUI and thus you cannot generate them similarly as you can run the computational module using the MatLab command. However, you can write your own generator in MatLab and write generated scaling factor into the HYDRUS input file ...
by Jirka
Wed Apr 10, 2019 12:53 am
Forum: HYDRUS (2D/3D)
Topic: How can I simulate zero runoff in a soil column simulation?
Replies: 2
Views: 38

Re: How can I simulate zero runoff in a soil column simulation?

HYDRUS (2D/3D) assumes that all excess water (i.e., Precipitation-Infiltration) is instantaneously removed by surface runoff. On the other hand, in HYDRUS-1D you can select the "Atmospheric BC with a Surface Layer" and water will accumulate at the surface until specified thickness layer is reached. ...
by Jirka
Mon Apr 08, 2019 2:56 pm
Forum: Hydrus 1D
Topic: Evaporation & profile thickness
Replies: 2
Views: 49

Re: Evaporation & profile thickness

There is more water available for evaporation (until it drains through the bottom) in a 5 m soil profile than in a 2 m soil profile. Make sure that you have the same spatial discretization in the topsoil layer in both simulations. Actual Evaporation calculated by the code is relatively sensitive to ...