Visual MODFLOW allows you to rotate the model grid over the site map (DXF of BMP format) to align the model with the site characteristics and groundwater flow direction. The finite-difference grid can be modified by adding, deleting, moving and automatically refining rows, columns and layers using standard 'point-and-click' methods. Automatic grid smoothing can also be used to identify and fix regions of the grid which are poorly designed and may lead to numerical instability. Since most aquifers are not 'flat' layers, Visual MODFLOW allows you to import layer surface data from ASCII (X,Y,Z) test files or SURFER (GRD) files. It even has a built-in checker to layer surfaces from intersecting each other. The layer surface elevations and thickness can also be visualized using plan view contours or by viewing the model grid in cross section. 
Pumping well or injection wells can be added, deleted, copied or moved using the intuitive well editing tools that allow you to graphically delineate the well screen interval and enter or import real-time pumping schedules from an ASCII text file. For sites with many pumping wells, Visual MODFLOW can also import all relevant pumping well data. Multiple well screens for a single well are easily accommodated while the pumping rate distribution between layers is automatically calculated based on the transmissivity of the layers through which it is screened. The well details and pumping schedule can be readily accessed and changed at any time. Observed head at the well can be adjusted according to the position of the well within the grid cell and radius of the well. 
All model properties including hydraulic conductivity (Kx, Ky, and Kz), Specific Storage (Ss), Specific Yield (Sy), and Porosity are assigned by either painting single cells, delineating polygons, or stretching a window around the selected grid regions. Each different property zone is color-coded according to differentiate zones with different property values. The property distribution from a single layer can be copied to any other layer(s) to eliminate repetitive steps involved in developing the model input files. Individual Property values and property zones can be edited at any time using the property database to make global modifications. For complex stratigraphy and varying hydraulic conductivity, it is important to be able to display the model property distributions in plan view and cross section to gain a proper perspective on the geometry of the site. 
MODFLOW boundary conditions supported by Visual MODFLOW include both steady-state and transient boundary conditions for Constant Heads, Rivers, General Heads, Drains, Horizontal Flow Barrier, Recharge and Evapotranspiration. Each type of boundary condition has a specific color code to differentiate them from one another. The convenient graphical tools allow you to assign these boundaries as either single cells, a polyline of cells with automatic interpolation of values, a polygon of cells or as a rectangular window of cells. For transient simulations, real-time schedules of boundary condition values can be entered directly or imported into the time schedule from an ASCII text file.
Forward or backward tracking particles can be easily assigned for determining advective transport, preferred flow pathways and delineating well capture zones. Visual MODFLOW's intuitive graphical tools allow you to easily assign single particles, lines of particles and a circle of particles. These particles can be easily toggled from forward to backward tracking with the click of the mouse. For transient simulations, the release times for the particles can also be assigned to groups of particles or individually to each single particle. This is particularly useful for demonstrating how the flow system and directions of flow change with time during varying pumping schedules or flow variation due to seasonal influences. 
Visual MODFLOW provides you with all the tools you need to calibrate your model to steady-state or transient flow conditions. The graphical tools allow you to easily assign single observation points or import data for situations where you have many different observation points and data. Once a single observation well has been entered, it can be copied or moved to any location within the model domain.
Visual MODFLOW supports transport boundary conditions for constant concentrations, recharge concentrations, sink terms and point sources. Each type of boundary condition has a different color code to differentiate it when multiple source terms are present. All boundaries can be assigned as either single cells, a polyline of cells with automatic interpolation of values, a polygon of cells or a window of cells. For transient simulations, real-time schedules of boundary condition values can be entered directly or imported into the time schedule.Graphically assign observation well locations and enter the steady-state or transient observed concentration information using an intuitive graphical window or by importing transient observation data. The tools available allow you to add, delete, move and copy selected observation points to anywhere throughout the model domain.
Input and modify the dispersion values of the model porous media. The various menu options allow you to assign color-coded dispersion values by either painting single cells, delineating polygons, or stretching a window around the selected grid cells. The properties from a single layer can be copied to other layers to eliminate unnecessary repetition. Individual dispersion values can be modified at any time using the color-coded property database.
Enter the layer-by-layer parameters necessary to calculate the sorption and/or degradation of the contaminant in the groundwater. These parameters include soil bulk density, first and second sorption constants, and first-order decay rates. Visual MODFLOW also now fully supports cell-by-cell reaction terms and time-varying constant concentration terms for MT3D96. This is an important consideration if you are planning to simulate local zones of higher reaction coefficients or sorption terms.| Basic | Time Steps: Set the number of time steps between each stress period and the time-step multiplier for each stress period. |
| Initial Heads | Assign initial heads values as constant by layer, import from ASCII (x,y,h) files or SURFER (GRD) files, or use heads from a previous MODFLOW simulation. |
| Solver | Select from either the SSOR, SIP, PCG2, or WHS Solver and customize the solver parameters and convergence criteria. |
| Recharge | Specify whether the recharge is assigned to the top layer only or to the upper most active layer in the model. |
| Layer | Specify the layer type for each layer in the model domain from the following: Type 0 - Confined, Constant S, T; Type I - Unconfined; Type II - Confined/Unconfined, Variable S, Constant T; Type III - Confined/Unconfined Variable S, Variable T. |
| BCF | Anisotropy: Select whether to use cell-by-cell values for Kx and Ky or assign the anisotropy ratio (Ky/Kx) for each layer in the model. Rewetting: Turn the cell re-wetting package on or off and customize the cell rewetting parameters. |
| Output Control | Output control options allow you to select which time steps to print to the MODFLOW Output file. |
| Pathlines | Modify the default run-time particle tracking options available from MODPATH. |
| Run | Execute the Win32 MODFLOW Suite to run the computational analysis of the model using the selected models (MODFLOW-96, MODPATH, Zone Budget and MT3D). |
| Translate | Translate the Visual MODFLOW files to MODFLOW, MODPATH, Zone Budget and MT3D readable input data files. |
| Advection | Select one of the following numerical methods for analyzing contaminant transport: - Finite Difference - Method of Characteristics - Modified Method of Characteristics - Hybrid Method of Characteristics |
| Output/Time | Select the times to output MT3D concentrations and specify the number of time steps for the simulation. |
| Initial Concentrations | Import the initial concentrations for each layer from an ASCII (x,y,c) file or a SURFER (GRD) file, or use a previous MT3D (UCN) file. |
Visual MODFLOW for Windows 95/NT now includes the Win32 MODFLOW Suite with MODFLOW-96, MODPATH, Zone Budget and MT3D (DOD v.1.5) compiled to run as Windows 95/NT 32-bit applications. This unique and powerful modeling utility actually provides you with the ability to control the numerical solution process by manipulating the solver parameters and convergence criteria while the solution is in progress. In addition, it provides a real-time graphical display of the solution convergence data and a detailed graphical summary of the Zone Budget results. 
After each successful run has been completed, the Win32 MODFLOW Suite automatically produces all the necessary files required for you to analyze and interpret the results and produce full-color, report-quality graphical presentations using Visual MODFLOW's postprocessing graphical features.
The contouring menu selection allows you to contour the results of the modeling simulation in plan view or cross section. The contouring selections are as follows: 
The contouring options button along the left-hand menu bar allows you to adjust the maximum, minimum, and interval of the contour lines, assign customized contour levels, adjust the speed/resolution of the contouring, change the color of the contour lines, and produce dazzling color fills of contoured results. The right mouse button can also be used to activate contour options that allow you to add, move or delete contour labels or add a contour line at any location by pointing and clicking. 
For transient simulations, Visual MODFLOW allows you to advance to successive output times or manually select the desired output time from a list of available time steps.
Visual MODFLOW provides powerful analysis tools for evaluating the quality of the fit between the model you have developed and the data you have observed in the field. A regression analysis is provided which compares the simulated results to the observed data at the various observation points throughout the model domain. A regression graph is displayed with calibration statistics including Mean Error and Normalized Root Mean Square Error. This analysis can be applied to all calibration points or to selected observation points only. For transient simulations, Visual MODFLOW creates temporal plots of head, drawdown or concentrations at any point throughout the model domain. In addition, Visual MODFLOW also displays the calibration residuals at each observation point to help you identify the areas where further refinements are required.
The flow pathlines provide an important representation of the flow direction and the path that the groundwater will follow from a specific location. Backwards particle tracking can also be used to indicate where the groundwater is coming from. Display options include viewing all pathlines as a projection through the entire model, viewing only those pathlines that start in the current layer, or viewing only the pathline segments which occur in the current layer. Time-related pathlines and time markers can also be displayed and individual pathlines or groups of pathlines can be toggled on or off using the mouse.Visual MODFLOW provides a detailed summary of the mass balance results and zone-to-zone flow exchanges. These mass balance results provide important information on the quality and reliability of the groundwater model you have built. If you do not achieve a reasonable mass balance between the flow entering the system and the flow leaving the system, your model will not yield reliable results. The mass balance results are summarized according to flow contributions from each type of boundary condition and can be used to identify regions where there are unreasonable flux rates. For a more localized summary of zone-to-zone flow exchanges, Visual MODFLOW uses Zone Budget to provide a detailed summary of the inflows and outflows from specified zones throughout the model domain.
Visual MODFLOW prints full-color, high-resolution graphics to any printer or plotter supported by Windows 95/NT. The graphical display of the simulation results and/or input files can be printed in portrait or landscape format as a full-page image or with a title block that describes the details of the model and the results being displayed. Color-shaded contours can be printed with or without a color legend. 
Visual MODFLOW project files can be visualized and animated in 3D using Visual Groundwater (see Visual Groundwater product description). All input parameters and modeling results are read into Visual Groundwater and displayed using color-shaded contouring and velocity vectors on slices, multiple 3D isosurfaces, and 3D pathlines.
Κατάλογος επιστημονικών προγραμμάτων της MP & Associates που είτε δεν υπάρχει αντιπρόσωπος στην Ελλάδα και έτσι τα εισάγουμε είτε υπάρχει και μπορούμε να σας τα προμηθεύσουμε μέσω αυτού.
Τελευταία Ενημέρωση 27 Ιουλίου 2004 - Last Revised on July 27, 2004
Προηγούμενη σελίδα