HYDRUS-2D: FAQ 11-20
11. Hydrus-1D versus Hydrus-2D; reasons to get both
Hydrus-1D and Hydrus-2D are two independent packages, which are being distributed independently, i.e., Hydrus-2D does not include Hydrus-1D. One can obviously solve a lot of 1D problems with a 2D package as well, although at the expense of computational time (2D will run about 3 times slower then 1D for 1D problems, since one need to use twice as many nodes to solve the same problem; two vertical columns of nodes) and user convenience. Both packages solve flow and transport for almost identical processes. I would not, however, recommend using a 2D code for many typical soil physics inverse problems (one and multistep outflow, evaporation method, etc., solute transport column studies, and so on) or for engineering problems, such as multi seasonal simulations of the recharge through landfill cover.
Thus, I believe that there is a reason to have both packages if you solve both 1D and 2D problems. However, the best for you may be to get only one package (probably 2D), to get yourself familiar with it, and after that to decide for yourself whether to get both or not.
12. Installation and manuals
One can install all our program by clicking on Setup.exe in particular folders of the HYDRUS CD or after unzipping the downloadable zipped file. Then one just follows the simple instructions given by the program on the screen. The installation program will create an icon on the desktop that one can use to start the program. Installation program also copies many examples for each included model on computer. You can view them all using the "project manager" within particular program (Hydrus-1D, Hydrus-2D, HYDRUS (2D/3D), STANMOD, and RETC). These examples are mostly described in detail in particular manuals.
All the manuals for the software on CD are in the DOCUMENT folder as PDF files. You will find there the general manuals for HYDRUS, Hydrus-1D, Hydrus-2D, and STANMOD, as well as for all models included into the STANMOD studio, i.e., CXTFIT, CFITM, CFITIM, CHAIN, 3DADE, N3DADE. Manual can also be downloaded from the HYDRUS web site. These manuals can be viewed and printed with Adobe Acrobat. This software is usually installed on all PCs today, and if you do not have one, it can be downloaded for free from the Internet.
13. Atmopheric BC on a potential Seepage Face
In the older versions of Hydrus-2D it could not rain on the seepage face. However, we have implemented into HYDRUS (2D/3D) an option, where this is be possible, i.e., atmospheric BC is be automatically applied on nonactive part of the seepage face.
14. Quick disappearance of the Execute DOS window
The following most probably causes this problem:
The FORTRAN code handles the description of the path to the input and output folder as a character string. This string is defined using a maximum of 80 characters. We suspect that you have installed HYDRUS somewhere deep in your system, such as "c:\program files\....\salinity laboratory\HYDRUS2D", and that the path is either too long (longer than 80 characters) or includes non ASCII characters. This would cause the problem as described.
Solution: Move your project folder to location with shorter path, e.g., "c:\program files\USSL\HYDRUS2D".
15. Running model in a batch
HYDRUS (2D/3D) allows users to select multiple projects and run them simultaneously using the “Calculate All Open Projects” or “Select Projects to Calculate”.
All older programs (Hydrus-1D, Hydrus-2D, STANMOD) allowed users to open and run several projects simultaneously. Simply open projects using “Project manager” and then start runs using “Execute program” for each active project.
To run several projects sequentially is more complex. One needs to prepare a batch file (e.g., run.bat) and files describing paths (e.g., path1, path2, etc) to project folders (to be run) in advance. One needs to copy these files into the program folder (e.g., c:\program files\ussl\hydrus1d). Additionally, the check box "Hit Enter at the End?" in the Output (Print) Information window has to be unchecked for all projects to be run sequentially.
Example of the “run.bat” file:
copy path1 level_01.dir
h2d_calc
copy path2 level_01.dir
h2d_calc
Example of the “Path1” file:
c:\program files\ussl\hydrus3d\mydirect\run1
Example of the “Path2” file:
c:\program files\ussl\hydrus3d\mydirect\run2
16. Time variable boundary conditions
The values specified as time-variable boundary conditions are values used during the entire time interval from the previous time to the actual time. Thus there is no linear interpolation during the time interval between two specified values; the boundary conditions change in steps. If there are time intervals during which fluxes are zero (no precipitations), they have to be specified s well. The values specified in column Prec, Evap, Transp are fluxes and thus units are in length/time. These are not totals or volumes!
17. "Export all" option
“Export All” option (in Hydrus-2D) exports values of all variables that can be displayed along a cross-section or boundary curves in the Graphics module. “Export All” option exports variables at different time levels, i.e., for time levels associated with each variable, depending which time level was displayed last for a particular variable (default is the last time level). Thus if one wants to export all variables for the same time level, one needs to display them all first for this particular time level (switching from one variable to the other at the same time level, before doing the cross-section), and then do the export.
We are going to change this function in version 2.102 and then the "export all" option will export all variables for the currently selected time-level even if they were not displayed in the view yet.
18. Network installation of the Hydrus-2D
Figure 1. Let’s assume that you have a Windows network according to Figure 1 and you want to install and activate HYDRUSydrus on 20 computers Client_01, …, Client_20. It doesn’t matter what Windows operating system is on the server or on client computers and it also does not matter if your network is “peer-to-peer” or if there is a Windows server. Here we call “Server” the computer that shares a disk or directory where Hydrus-2D will be installed.
Steps to be done on server:
1/ Create a directory on server (for example D:\Hydrus) and share this directory (for example under name “Hydrus”). Give all clients full control over the directory.
2/ Create a subdirectory D:\Hydrus\Installation and copy Hydrus-2D installation program into this directory -2D runs correctly as the full version on this computer
Steps to be done on all clients:
3/ Run Server\\Hydrus\Installation\Setup.exe and install Hydrus-2D to directory Server\\Hydrus
4/ Run Server\\Hydrus\Hydrus.exe and make sure that Hydrus-2D runs correctly as a demo version.
5/ Repeat steps 3 and 4 on all client computers. This must be done to install system DLLs to local Windows systems and to register Hydrus-2D components on all client computers.
Steps to be done on ONE of clients:
6/ Activation of Hydrus-2D on one client will automatically activate Hydrus-2D on all clients:
- Run Hydrus-2D
- In the main menu go to Help – Authorization – Network License – All Client Computers – Activate Hydrus-2D and Meshgen…
- Send generated "license order information" to IGWMC
- Enter received authorization code from IGWMC
- Make sure that Hydrus-2D runs correctly as the full version on this computer
Steps to be done on server - only if you are going to run Hydrus-2D on the server
7/ Activate Hydrus-2D on server:
- Run Hydrus-2D
- In the main menu go to Help – Authorization – Network License – Server – Activate Hydrus-2D and Meshgen…
- Send generated "license order information" to IGWMC
- Enter received authorization code from IGWMC
- Make sure that Hydrus-2D runs correctly as the full version on this computer
Now Hydrus-2D should run correctly on all client computers as the full version.
Remarks:
8 / You can install additional clients (or install Hydrus-2D on other clients) later and HYDRUS will be activated automatically on them (if at least one client has been already activated).
9/ If your license is for N computers then it means that only N computers can be running Hydrus-2D at the same time. But you can have Hydrus-2D installed on more (>N) clients and each client can run full version of HYDRUS2D if number of currently running H2D is less than N.
When one uses the first-type (Dirichlet or concentration) boundary condition, one prescribes the concentration at the boundary (not the flux into the domain). Since solute flux consists of two components, i.e., convective and dispersive flux, both these fluxes are active on the boundary as well. Initially there is a large concentration gradient and thus the dispersive solute flux is large. In this case one has much larger flux into the domain than if one uses the third-typ solute flux boundary condition.
We always recomend using the third-type boundary condition since that is more physically realistic boundary condition. Dirichlet boundary condition is not a physical boundary condition (and for above reasons it does not conserve mass). One could use it only if there is, for example, large reservoir of contaminant in contact with the transport domain, and thus one can assume that boundary concentration is fixed.