Graphical User Interface

Thanks to the graphical tools of WMS, with standard MS Windows functionality, building models and viewing results is very easy and intuitive. All modeling parameters are entered through interactive graphics and easy-to-use dialog boxes. Though the software reads and writes native model input/output files, there is no need to worry about formatting text files to get the models to run nor will you need to search through text output files to find the results from the model run.

The Data Tree Window of WMS has been developed to give you GIS-style, quick access to data layers and display settings. By simply clicking on data layers you can:
 Turn display on/off
 Convert data to other formats/types
 Project data to a different coordinate system
 Control display settings
 Set the active data set for editing

The Data Tree Window also allows you direct access to modeling parameters/tables for control of your hydrologic model. You will find that managing data for hydrology and hydraulic modeling is easier than ever before in this specialized system.

Thanks to simple CAD/GIS style tools and functionality, you will find that manipulating digital terrain data and GIS data to delineate watersheds and compute model input parameters is very smooth. Further, presentation of results of your work will be impressive and easy to understand.

Graphics and Visualization

WMS is a powerful graphical tool for model creation and visualization of results. Models can be built using digital maps and elevation models for reference and source data. During the model building process, the graphical representation of the model allows quick review and presentation of your work. Fully 3D views, with contouring and shading, of your model allow anyone to see and understand the domain and parameters of your analysis.

Implementation of OpenGL technology in WMS now allows faster 3D rendering, near real-time rotation, and immediate refresh of vector and raster (image) data. WMS also now supports color transparency, allowing layered presentation of results in a single view.

Presentation of transient model input or output data is better than ever with the improved FilmLoop Editor of WMS. The filmloop approach allows you to create AVI presentations or changing conditions/results in your model.  For example, you might create an animation showing flood depths on the land surface of your model over some time frame.  Another application could be the animation of gridded rainfall data used for input to a hydrologic model. Spatial and temporal variation in data is presented with amazing clarity with such graphical tools.

Basic watershed  and river data display options include elevation contouring, basin-boundary outline or color fill, streams, time of concentration flow path plotting, base map (orthophotos, USGS Quad maps, etc.) rendering, and many others.  Watershed data such as areas, slopes, flow distances, basin centroids, etc. can be displayed as well.  Model results such as hydrographs can be plotted with a variety of plotting options.  Further, floodplain results can be reported as flood depth maps, flood extent maps, and flood impact maps - all scaled and reported in real-world coordinates.

WMS Models

The Watershed Modeling System supports several industry-standard, numerical models to compute peak flow, hydrographs, water quality, etc.  Each model is supported through the Hydrologic Modeling Module with a completely integrated interface for parameter input, job control, and output review.  A model checker is also featured with each model; this checker guides you to correct errors or omissions in model input data. The models available for use with WMS are described below - each model is included with the WMS installation (model executable files and documentation) and is fully linked with the WMS software.


Developed by the Hydrologic Engineering Center, HEC-1 is the most commonly-used lumped parameter model available.  HEC-1 is designed to simulate surface runoff from a single precipitation event.


National Flood Frequency (NFF)
The National Flood Frequency program, developed by the USGS in cooperation with FHWA and FEMA, evaluates regional regression equations for estimating flood peak discharges.


Developed by the NRCS, TR-20 is designed to compute surface runoff from natural or synthetic rainstorm events.


Rational Method
One of the simplest and best-known methods of hydrology, the Rational Method computes peak discharge from an area based on rainfall intensity and a runoff coefficient.


TR-55 was developed by the NRCS as a simplified method to compute storm runoff in small, urbanized watersheds.


The Hydrological Simulation Program - FORTRAN simulates hydrologic and water-quality processes on land surfaces, streams, and impoundments. It is Often used in the development of TMDLs.


MODRAT is the specialized Modified Rational Method program used by the County of Los Angeles, California to compute surface runoff.


HEC-RAS is a 1D hydraulic model for computing water surface profiles for steady state or gradually varied flow.


The StormDrain model does complete storm sewer network analysis for steady state or transient flow conditions. It is based on the HYDRAIN analysis code from the FHWA.


Developed by USACE ERDC, GSSHA is a distributed (2D) hydrologic model developed for analysis of surface runoff, channel hydraulics, and groundwater interaction. Water quality and sediment transport are also supported.


CE QUAL W2 is a 2D (profile) hydraulic model used for water quality analysis in rivers and reservoirs where vertical variation analysis is required.



WMS Modules

The WMS interface is separated into several modules; these modules contain tools that allow manipulation and model creation from different data types. Click on the modules liste below for details of each componenet of WMS:

 Map Module

 Drainage Module

 GIS Module

 Hydrologic Modeling Module

 Terrain Data Module

 River Modeling Module

 2D Grid Module

 Scatter Point Module

Map Module

The Map module provides a suite of tools for defining watershed data in a GIS and then using the information to directly create and manage hydrologic and hydraulic models, or as a support utility for data development with either TINs or DEMs. Results of watershed and floodplain delineations can also be saved in the map module and converted to GIS data layers for export.

Images are one of the four basic object types that is supported in the Map module. An image is typically a scanned map or aerial photo in TIFF or JPEG format. Images can be imported to WMS and displayed in the background to aid in the placement of objects as they are being constructed or simply to enhance a plot. Images can also be draped or "texture mapped" onto a TIN or 2D grid.

The Map Module supports the following image types:

Land Use and Soil type layers can be created using feature objects in the Map module and then used to compute curve numbers or map other important modeling parameters. Other layers are also used for computing time of concentration or lag time, cutting cross-sections, mapping NFF regions, mapping rainfall and other parameters for the LA County modified rational (MODRAT) model, and streams for 2-D analysis using GSSHA.

A rough boundary and stream network can also be used to generate a TIN or two-dimensional finite difference grid that conforms precisely to streams and other important hydrologic features. Feature objects can also be used to create polygonal boundaries of soil type or land use to aid in the computation of curve numbers for hydrologic analysis.

Within the Map module there are several other tools which can be helpful in either setting up models or presentation of results to a client. Tools for reading and writing of CAD files (DXF and DWG) and part of the Map Module.  Also included is a set of tools for adding simple graphics and annotation to a plot. These tools are not intended to be a full-featured drawing package as would be found in products like AutoCAD or Corel Draw. However, they can be very useful for adding titles, arrows, and other annotation to a plot so that the plot can be directly included in a project report without the need to import the plot into an external drawing package prior to report generation.

GIS Module

Past versions have interfaced with GIS data primarily through shape files. Because WMS is not a GIS management of these kinds of data (in particular land use and soils layers) has been limited. The ability to process large files, clip out regions of interest, or join additional soils database tables to extract important information. Version 7.0 has undergone some major changes in the way that GIS data can be read, displayed, and used for developing hydrologic modeling parameters. The tools for reading, displaying, and converting GIS data have been separated from the Map module to form a new GIS Module. The GIS module has two modes of operation:

 1) If you have license of ArcView (ArcEdior, or ArcInfo as well) version 8.0 or higher then you can enable the use of ArcObjects within WMS. This essentially allows you to run ArcView within WMS and includes the capability to open any GIS data file that ArcView can open including images, ESRI formatted coverages, CAD files, new geodatabases, and shape files. ArcObjects functions also allow the control of display, table viewing and joining, and many other ArcView capabilities within WMS.

2) If you do not have a license of ArcView 8.0 or higher then the GIS module will allow you to read in and display shape files as GIS layers. Only a portion of the capability for displaying data, tables, and other GIS functions are available with shape files, but unlike previous versions of WMS large shape files are more efficiently read and displayed as initially the shape file is not converted to a WMS coverage.
A key feature of the new GIS module is that individual features (points, lines, polygons) can be selected from the GIS layer and then only the selected features are converted to feature objects in WMS coverages. This allows you to read in a large soils data layer, select the soils that cover your watershed, and only convert these soils to the WMS coverage.

Previous versions required this kind of manipulation to be done with ArcView or some other GIS tools, but now your GIS data can be managed completely using the tools in WMS. If you own a license of ArcView then you will have additional access to file formats and other advanced display capabilities.

Terrain Data Module

In WMS 7, we now have a Terrain Data module where you create, edit, and preprocess all of your digital terrain data, whether it is a TIN or DEM. The Drainage Module then is used to delineate a watershed from either a TIN or a DEM.  The terrain data in WMS can be contoured, displayed in oblique view with mapped images and hidden surfaces removed, and several other display options that can be set to visualize and understand the terrain surface better.

At first glance you may wonder if we mixed and matched the TIN and DEM tools just to confuse old users. However, there are good reasons why we have done this. We have added several tools that allow you to edit elevations and process both TINs and DEMs to process them not only for watershed delineation, but also for hydraulic modeling using our HEC-RAS interface tools. Some of the powerful tools now awailable in the Terrain Data Module include:

 The ability to edit DEM elevations. You can now define a feature arc and then in a DEM elevation-editing environment adjust the elevations. This could be used to ``carve" out a canal or other small stream not accurately represented by the original elevations of a DEM. You could also insert a highway embankment or other such structure that may act as a levee and alter watershed or flood delineation.
 Much faster and more robust TIN triangulation and processing.
 Tools to thin LIDAR and other dense triangulation sets are provided.
 Tools to extract the significant elevation points from DEMs have been implemented.
 Contours from TINs or DEMs can be exported as feature lines (then to shape files for sharing in a GIS).
 Options to merge data from a TIN and a DEM together to create a composite elevation data set.
 Tools to quickly convert a DEM to a TIN and vice versa.

A major feature of the Terrain Data Module is the option to generate flood depth and extent maps based on the digital terrain model and water surface data. WMS contains the most complete and powerful floodplain delineation options available. Some of these are: lateral interpolation of W.S.E. along cross sections, stream center-line interpolation of W.S.E. between cross-sections, fully 2D interpolation of flood depths over the surface of the terrain, flood barrier inclusion (buildings, levees, walls, etc.) without tedious terrain editing, flow path/distance restiction options. Contouring and 3D rendering of flood maps is also part of the Terrain Data Module.

Since much of the power of WMS is dependant on using digital terrain data, WMS can import/export several formats of digital terrain data including:
 USGS DEM files (all formats)
 ARC/INFO ASCII Grid files
 USGS NED files
 GRASS grid files
 DTED grid files
 Scatter survey points (XYZ text format)
 Polyline contours from GIS or CAD
 TINs from CAD software (DXF or DWG)

Information on terrain data types and aquisition of such data can be found at the following URL. The WMS developers and users have created a website for reference on geospatial data aquisition, along with examples, step-by-step instructions, and user tips.
WMS GeoSpatial Data Aquisition -

Drainage Module

The Drainage Module in WMS allow you to automatically delineate streams and watershed/sub-basin boundaries based on the land surface represented by the DEM or a TIN.  One of the best features of WMS is the flexiblity and control you have when using the automated delineation method.  You can use any stream network (automatically generated or manually digitized) in conjunction with a land surface to delineate drainage areas. You can also manipulate watershed boundaries generated by WMS or create them entirely on your own and let WMS match the terrain data with the watershed delineation you know is correct.

A complete watershed model can be contructed using the Drainage Module.  Basin characteristics and routing parameters such as slopes, distances, flow paths, etc. are automatically determined as part of the delineation process. The option to automatically create storage features (reservoirs/detention ponds) is also included. WMS will compute elevation-volume-discharge curves based on the land surface and streams of your watershed model. All parameters computed during delineation are set up for input to any of the models supported by WMS - the software places the appropriate parameter for each possible model in the input fields so you can confirm/review the data easily.

Hydrologic Modeling Module

The Hydrologic Modeling Module, sometimes refered to as the Tree Module, is the center for hydrologic modeling input, execution and output review.  Each hydrologic model supported by WMS has a complete graphical interface in this module (HEC-1 or HMS, TR-20, TR-55, NFF, Rational Method, HSPF, MODRAT). The model interfaces allow you to view and edit model input parameters quickly and easily.  The watershed models built using the Map or Drainage Modules are linked to a simple schematic (tree) representation in the Hydrologic Modeling Module.  This allows you to quickly select and edit basin parameters and stream (reach) parameters.

WMS reads and writes native model files (such as HEC-1 files) from this module.  WMS allows you to use model files created in other systems or by hand by reading in the modeling information and building a schematic representation (tree) for you to use as you update or review the model. You can save any model back to a native file format - including the new HEC-HMS format.

The Hydrologic Modeling Module also contains the tools for computing complex hydrologic parameters (using your digital terrain or GIS data) needed for input to a model. This functionality includes:

Time of Concentration Computations

Calculate Tc based on basin-data based regression equations (such as the SCS Lag Time equation) or use equations assigned to actual flow paths, subdivided into flow regimes (sheet flow, channel flow, etc.) as recommended by the FHWA or TR-55 Tc Methods.

Curve Number (CN) Calculations

Overlay Land Use and Soil Type data on your watershed and let WMS compute an area-weighted CN for each basin.

Green & Ampt Calculations

Overlay Land Use and Soil Type data on your watershed and let WMS compute average Green & Ampt parameters for each basin.

Rainfall Depth Mapping

Use a iso-pluvial grid or map to allow WMS to compute an area-weighted rainfall depth for each basin.

HSPF Segment Mapping

Overlay Land Use data to divide your HSPF model into different pervious and impervious land segments.

Runoff Coefficient Calculations

Overlay Land Use or zoning data to determine area-weighted runoff coefficients (C) for use with the Rational Method.

Once a model has been completed, tools in this module allow you to open flow results (peak flow reports, hydrographs, etc.) and plot them with your model. You can also export model results to more useful formats (spreadsheets, tables. etc.) from this module. Anyone who has tried to sort through a complex model output file will appreciate this functionality.

Finally, the Hydrologic Modeling Module contains several ``Calculator" tools for colculating modeling input or analyzing model output. These include:

Detention Basin (Reservoir) Calculator

Create Storage-Capacity-Dischage curves based on simple geometry or land surface contours. You can then route any hydrograph through a detention basin or use these curves as input to HEC-1, TR-20, MODRAT, or the Rational Method.

Culvert Calculator (HY-8)

Set up and run a full culvert analysis using the HY-8 analysis engine created by the FHWA.

Weir Calculator

Perform simple computations to determine flow over a weir given a head value or determine head on a weir given flow.

Open Channel Calculator

Use generalized cross-sections (trapezoidal, circular, etc.) or a custom cross section (station/elevation points entered into WMS or cut automatically by WMS from a land surface model) to compute flow, depth, Frounde Number, critical depth, etc.

Curb & Gutter Calculator

Use the method recommended by the FHWA for gutter analysis and inlet design.

River Modeling Module

The primary purpose of the hydraulic modeling interface within WMS is to process digital terrain and map data (TINs and coverages) to build the basic geometry necessary for a 1D Hydraulic Model.  Currently the only major model supported is HEC-RAS, but additional models, including the FloodWave and BRI-STARS models will be supported in future versions. See the
WMS Models section of this page for more information on each hydraulic model.

 When creating a 1D hydraulic model, WMS will help you do the following:
 Creating/editing stream center lines, bank lines, and cross sections
 Assigning roughness values to line properties on the cross sections automatically from map data such as land use.
 Extracting cross sections from the TIN and initializing the 1D Model with the cross section and connectivity data.
 Export the GIS data and finish defining HEC-RAS (or other model).
 Importing HEC-RAS results for creation of floodplain maps

Scatter Point Module

The Scatter Point module is used to interpolate data from scattered points to grids or TINs. WMS supports several interpolation schemes including linear, natural neighbor, inverse distance weighted, and Clough-Tocher.

Interpolation from scatter data is used primarily for floodplain delineation in WMS. Flood stages can be input anywhere on a scatter data point; WMS then uses interpolation to ``fill" the floodplain and compute extents and depths.

2D Grid Module

The 2D Grid module is used for surface visualization and for the development of distributed (2D) rainfall/runoff analytical models. For example, the user can discretize a watershed into a number of grid cells and then define important rainfall, infiltration, and channel properties at grid cells in preparation for running a 2D model such as GSSHA.  Any parameter such as hydraulic conductivity or rainfall intensity may be interpolated from a set of scattered data points to the grid. Results of the 2D analysis can then be contoured on the grid or displayed with hidden surface removal and color fringes to display the variation in the computed results.

WMS includes several tools for the creation and editing of 2D finite-difference grids in the 2D grid module.  Grids can be automatically generated using the Map and Terrain Data Modules or they can be created based on options set by the user in the 2D Grid module.

Hardware Requirements

Minimum recommended configuration:
Windows NT/Me/2000/XP
500MhZ processor
128 MB RAM
1024x768 w/ High Color
100 MB disk space

Scientific Software Group    P.O. Box 708188   Sandy, Utah 84070
Phone (801) 208-3011   Toll Free (U.S.) 1-866-620-9214    Fax (801) 302-1160    E-mail
Copyright 1998   Scientific Software Group    All rights reserved