U.S. Salinity Laboratory, USDA, ARS
450 West Big Springs Road
Riverside, CA 92507-4716Tel: 909-369-4850
U. S. Salinity Laboratory, USDA, ARS
450 West Big Springs Road
Riverside, CA 92507-4617
HYDRUS-2D is a Microsoft Windows based modeling environment for analysis of
water flow and solute transport in variably saturated porous media.
It includes the two-dimensional finite element model
SWMS_2D for simulating
flow and solute transport in variably saturated media. The model is
supported by an interactive graphics-based interface for
data-preprocessing, generation of a structured mesh, and graphic
presentation of the results. Optionally, the modeling environment includes an mesh generator for
unstructured finite element grids, MESHGEN-2D.
The MS Windows based Graphics User Interface (GUI) manages the
geographical, hydrogeologic and physical inputs required to run SWMS-2D, as
well as grid design and editing, parameter allocation, problem execution,
and visualization of results.
The program includes a set of controls that allow the user to build a flow
and transport model and perform graphical analyses on the fly. Both input
and output can be examined using areal or cross sectional views, and line
graphs. The HYDRUS-2D shell program translates all geometric and parameter
data into the SWMS-2D input format. File management is handled by a
sophisticated project manager.
Automatic Mesh Generation
Data preprocessing involves specification of the flow region having an arbitrary continuous shape bounded by polylines, arcs and splines, discretization of domain boundaries, and subsequent generation of an unstructured finite element mesh. HYDRUS-2D comes with an optional mesh generation program MESHGEN-2D by PC-Progress. This program, based on Delaunay triangulation, is seamlessly integrated in the HYDRUS-2D environment. In the absence of the MESHGEN-2D program, the HYDRUS-2D shell provides an option for automatic construction of simple, structured grids.
Post-processing is also done in the shell. Areas of interest can be zoomed into, and vertical scale can be enlarged for cross-sectional views. Output graphics include 2D contours (isolines or color spectra) in areal or cross-sectional view for heads, water content, velocity, and concentrations. Included are velocity vector plots, animation of graphic displays for sequential timesteps, and linegraphs for selected boundary or internal sections, and for variable-versus-time plots. The mesh can be displayed with boundaries, and numbering of triangles, edges and points. Observation points can be added anywhere in the grid. Viewing of grid and/or spatially distributed results (pressure head, water content, velocity, or concentration) is facilitated using high resolution color or grey scales.