HYDRUS-2D: FAQ 1-10
1. New features in version 2.0 of Hydrus-2D
New features in version 2.0 of Hydrus-2D as compared to version 1.0
Version 2.0 is a fully 32-bit application, contrary to version 1.0, which was 16-bit application.
- Better graphics and overall user-friendliness of the software package.
- Compatibility of tables in Hydrus-2D with Windows spreadsheets, such as MS Excel.
- Different options for the description of the soil hydraulic properties (van Genuchten-Mualem, Brooks and Corey, modified van Genuchten - Mualem)
- Hysteresis in the soil hydraulic properties
- Multiple solutes, nonlinear and nonequilibrium (two-site sorption, mobile-immobile water) solute transport, volatile solutes
- Heat transport
- Inverse parameter estimation
New features in HYDRUS (2D/3D) as compared to version 2.0x of Hydrus-2D.
List of new features can be found here.
2. Overland flow
HYDRUS (2D/3D) does not directly calculate overland flow, neither the accumulation of water at the soil surface. This is done only in Hydrus-1D. Hydrus-2D assumes that all the water in excess of the infiltration capacity is immediately lost to surface runoff. We do have plans to include the option that would take care of overland flow, but we have not implemented that yes.
Hydrus-1D has an option that water can accumulate at the soil surface and possibly infiltrate later. Optionally, one can start with certain depth of water standing at the soil surface, and allow this water to infiltrate.
3. Conversion of projects from previous versions
Conversion of projects from version 1.0 of Hydrus-2D to version 2.0
Please follow the following procedure:
- Create a new folder and copy all old projects into this new folder.
- Open Hydrus-2D version 2.0.
- Open Project manager, switch to the Workspace plane.
- Click new project, give the name and description (e.g., old projects).
- Browse to the new folder with the old projects.
- Check the check box Connect a directory with projects of the Hydrus-2D version 1.0.
- Click OK. Hydrus-2D will create *.h2d files for each old project.
- That's it.
Conversion of projects from version 2.0 of Hydrus-2D to HYDRUS (2D/3D)
See the instructions in the user manual.
4. Contour levels
In Hydrus-2D, contour levels are automatically selected by the code. It is always in the interval between the minimum and maximum value either during the entire simulation or for the one particular picture (you can switch by “Options->Color spectrum for all time levels”). Thus, user cannot specify the maximum and minimum contour levels; this is selected automatically by the code. Hoverer, for comparison of various simulations, one can define the contour levels (initial level and constant step between contours) for contour maps (see “Options->Isolines Parameters”).
5. Missing *.h2d files
You can use any *.h2d file and just rename them using names of particular projects (folders). These file (contrary to our initial intentions) do not include any project specific information other than that they inform Hydrus-2D about an existence of the Hydrus-2D project.
6. Scaling factors
Is there any possibility to get stochastic distributed soil properties (for example hydraulic conductivity) for a part of the flow-domain only and not the complete one?
Scaling factors can be used to simulate heterogeneous soil conditions. Hydrus-2D always generates scaling factors for the entire domain. However, it should be relatively easy to change that.
- If you want to generate scaling factors only in part of the domain and keep the rest homogeneous, you can generate them for the entire domain and then manually put the scaling factors back to one in the homogeneous part which is trivial).
- If you want to have parts of the domain with different stochastic parameters (variance and correlation length) then you have to generate a realizations for each set of parameters, and write a short program that would read the coordinates (Meshtria.txt) and scaling factors for particular parameter sets (Domain.dat) and based on the coordinates then select the right ones and create a new input file Domain.dat.
7. Operating systems (Windows 2000)
The current versions (2.0x) of all our commercial software (i.e., Hydrus-1D, Hydrus-2D, HYDRUS and STANMOD) works on all MS Windows operating systems, starting with Window 95 (i.e., Windows 95, Windows 98, Windows 2000, Windows NT, Windows ME, WindowsXP, Windows Vista, ...). The only problem was that the installation software (Install Shield) on our older CDs (1999 and older) would not recognize the newer operating systems and thus does not do the installation (obviously at that time we could not predict what new operating system upgrades will be introduced by Microsoft). Had the installation worked, HYDRUS would have worked without any problems. Please contact IGWMC and ask for a new HYDRUS CD that has a newer version of the installation program. The code should work with your current authorization file. There should be no cost involved, except perhaps for shipping and handling. You can also download the installation program directly from our web page.
8. Fluxes through a plane of interior nodes
Fluxes through a plane (cross-section) inside of the domain: Hydrus-2D does not have an option that would output fluxes through a plane inside of the domain. We have implemented this option only in HYDRUS (2D/3D) Only nodal fluxes (Vx and Vz in the output file v.out) are output of Hydrus-2D. I guess one could work with these to get the information you need, although it would be quite a tedious work. a) One would need to convert outputs into ASCII files, and then select fluxes in specified nodes, and integrate them. Or b) one could make a cross-section for fluxes in the Geometry module, export it, and then integrate in a spreadsheet.
9. Fluxes along specific portions of boundaries
Fluxes along specific portions of boundaries: HYDRUS integrated fluxes along a specific type of boundary (e.g., seepage phase) and report them as actual and cumulative fluxes in v_mean.out and Cum_q.out files, respectively. HYDRUS also reports the actual nodal fluxes at specific print times at all boundary nodes in the Boundary.out file. Thus, if you need an actual flux along only a part of a specific portion of boundary (part of seepage face), you can just sum up the Q values for those nodes. In the graphical interface, get nodal numbers you are interested in, and the in, e.g., Excel, open the Boundary.out file and sum up these Q values.
Since for given geometries, it may be easier to hardcode some of the things you want directly into the code (as opposed to digging it out from the output), do not hesitate to ask as for the source code of the computational module, if you wish to do that.
10. Concentrations in the objective function
Older versions of HYDRUS codes could consider only the liquid phase resident concentration in the objective function, and thus can be calibrated only against this type of concentration. In the newer versions (3.0 of Hydrus-1D and in HYDRUS (2D/3D), we have implemented options that allow users to consider also the flux concentrations and total resident concentrations in the objective function. Total concentrations would include not only the sorbed concentration at equilibrium with the liquid concentration, but also the kinetically sorbed solute and/or solute in the immobile liquid phase, i.e., solute measured for example by TDR.