HYDRUS - Microsoft Windows Program for Simulating Water Flow and Solute Transport

New Features and Changes (related to GUI):

1. Support for complex General three-dimensional geometries (3D-Professional Level).
2. Domain Properties, Initial Conditions, and Boundary Conditions can be specified on Geometric Objects (defining the transport domain) rather than on the finite element mesh.
3. New FE-mesh generator for unstructured 3D meshes. Supports mesh refinements and stretching.
4. Background layers facilitating graphical input of data.
5. Import of geometry and background layers from a number of formats (DXF, STL, TIN, BMP, ...)
6. Import of various quantities (e.g., domain properties, initial and boundary conditions) from another HYDRUS projects even with (slightly) different geometry or FE mesh.
7. Support of ParSWMS (a parallelized version of SWMS_3D).
8. Support of UNSATCHEM (a module simulating transport of and reactions between major ions).
9. Support of a new CWM1 constructed wetland module.
10. The Mass Balance (Inverse) Information dialog window enables to display texts larger than the capacity of the Edit window.
11. Constructed Wetland Parameters commands added to the main menu and navigation tree.
12. Root distribution can be specified using GUI parallel with the slope of hillslopes.
13. Display of results using Isosurfaces.
14. On-line activation and deactivation. HYDRUS 2.x can be activated and/or deactivated via internet without asking for activation codes.

New Features and Changes (related to computational modules):

1. New, more efficient algorithm for particle tracking. Time-step control to guarantee smooth particle paths.
2. Initial conditions can be specified in the total solute mass (previously only liquid phase concentrations were allowed).
3. Initial equilibration of nonequilibrium solute phases with equilibrium solute phase (given in initial conditions).
4. Gradient Boundary Conditions (users can specify other than unit (free drainage) gradient boundary conditions).
5. A subsurface drip boundary condition (with a drip characteristic function reducing irrigation flux based on the back pressure).
6. A surface drip boundary condition with dynamic wetting radius.
7. A seepage face boundary condition with a specified pressure head.
8. Triggered Irrigation - irrigation is triggered by HYDRUS when the pressure head at a particular observation node drops below a specified value.
9. Time-variable internal pressure head or flux nodal sinks/sources (previously only constant internal sinks/sources).
10. Fluxes across meshlines in the computational module for multiple solutes (previously only for one solute).
11. HYDRUS calculates and reports surface runoff, evaporation, and infiltration fluxes for the atmospheric boundary.
12. Water content dependence of solute reactions parameters using the Walker’s [1974] formula was implemented. (Walker, A., A simulation model for prediction of herbicide persistence, J. Environ. Quality, 3(4), 396-401, 1974.)
13. An option to consider root solute uptake, including both passive and active uptake [Šimunek and Hopmans, 2009].
14. The Per Moldrup’s tortuosity models [Moldrup et al., 1997, 2000] were implemented as an alternative to the Millington and Quirk [1960] model.
15. An option to use a set of Boundary Condition records multiple times.
16. Executable programs are about 1.5 - 3 times faster than in the standard version due to the loop vectorization.
17. A new CWM1 constructed wetland module (in addition to the CW2D module).
18. New options related to the fumigant transport (e.g., removal of tarp, temperature dependent tarp properties, additional injection of fumigant).

Fixed Errors:

1. Fixed error: The Wetland module had a wrong format statement when writing the CumQ.out file.
2. Fixed error: FE-mesh generation could fail if stretching factors were >1 and the domain boundary contained polylines and (at the same time) splines or arcs.
3. Fixed error: Activation energy coefficients in the temperature dependence functions were incorrectly converted when time units changed.
4. Fixed error: Unit conversion of the area associated with transpiration was incorrect when length units changed.
5. Fixed error: Conversion of some first- and zero-order rate constants with respect to length units.

• HYDRUS 2D/3D installation program has been optimized for Windows Vista
• Colors for graphical display of Materials, Sub-regions and Anisotropy can now be customized within the groundwater model HYDRUS 2D/3D
• New option for importing domain geometry from a text file in HYDRUS 2D/3D; there is a new key word that allows for the import of thickness variables with multiple sub-layers with variable thickness into the groundwater model

HYDRUS 2D/3D is a Windows based modeling environment for analysis of groundwater flow and solute transport in variably saturated porous media. Computational finite element models are included in HYDRUS 2D/3D for simulating both 2D and 3D transport of water, heat and solutes in variably saturated media. A parameter optimization algorithm is also available in HYDRUS 2D/3D for inverse modeling of soil hydraulic and/or solute transport parameters. HYDRUS 2D/3D is also supported by an interactive graphics-based interface for data pre-processing, generation of structured and unstructured finite element mesh, and graphic presentation of the result