Multi-CAD Magazine
BOSS RiverCAD
March 1998
by Geoff Harrod
As its name aptly implies, this is a CAD program concerned with rivers. BOSS International is the name of the company in Wisconsin that produces it. Its main purpose is to facilitate the analysis of natural run-off conditions over an area of terrain, including stream flow volumes and their routes, and to model impounding areas. Analyzing stream flows is a vital precursor to designing road work embankments, culverts and bridges, and of course dams. Since RiverCAD works from terrain data in 3D computer model form it follows that it is relatively simple to modify the terrain as might be proposed for some structures or earth works and be able to analyze the resulting modified flow or impounding conditions.
RiverCAD began as BOSS RMS, an add-on application for AutoCAD. RiverCAD is in effect the new version of that, but also marks the move to being an independent Windows program that does not need any CAD program to run with. This greatly reduces its cost of course. In fact, RiverCAD uses the compilable-module version of FelixCAD embedded within itself. Since FelixCAD mimics AutoCAD's rationale and command logic to a great extent, users of previous versions of RMS will not find the working environment in RiverCAD significantly different to what they are used to.
The copy I received over the Internet for reviewing was 'hot off the press' and being a sometimes programmer and Beta tester, I was not surprised to find some 'loose ends'. I am sure those will be fixed up in the release version, so I will not dwell upon them. The most obvious were in the on-line help, and that did give me some problems since I received the software with no manuals. The help seems to be the same as was applied to the AutoCAD version. Most of it applies equally well, but the section on plotting is wrong since FelixCAD 2.1 does not have any PaperSpace, which RMS evidently relied upon.
The sample files provided included some assembled plot sheet images, so it is clear RiverCAD uses additional FelixCAD drawing sheets in lieu of PaperSpace. Felix allows up to four drawings in the system at once, tiled or cascaded on screen, which AutoCAD cannot do, so RiverCAD's convenient plot sheet composition system is still there, but done differently. I couldn't explore this fully because this down-loadable demo version has the save and plot facilities blocked off.
Version 3 of FelixCAD is scheduled to have PaperSpace, so maybe BOSS are leaving the help as is ready for the next update. The FelixCAD manual is provided as an Adobe Acrobat PDF file, with the viewer program.
If you have ever seen FelixCAD, you will recognize RiverCAD on screen. But the menus have been added to considerably and there are extra optional floating toolboxes for the numerous RiverCAD special facilities.
But the real guts of RiverCAD is of course its surface water analysis facilities. Let's look at what it can do.
The analysis engines used by BOSS RiverCAD are the U.S. Army Corps of Engineers Hydrologic Engineering Center water surface profile computation models HEC-2 and HEC-RAS. Since these analysis engines have been compiled as 32-bit Microsoft Windows applications, they are much faster than the standard Army Corps versions.
All HEC-2 and HEC-RAS modeling data is stored directly in the drawing file as extended entity data; there are no external
files to maintain. A RiverCAD model is developed by:
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Defining cross-section locations and the corresponding ground geometry using any combination of 3D digital contour maps, 2D digital contour maps, 3D digital terrain models, 3D TINs, XYZ coordinate data, USGS DEM (Digital Elevation Map) data, hard-copy contour maps, hard-copy cross-section plots, on-screen digitizing, manual data entry, importation of complete or partial HEC-2 input card files, and importation of complete or partial HEC-RAS data sets.
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Defining the starting water surface profile conditions (ie., discharge, starting elevation, etc.), and other necessary parameters.
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Defining any floodway encroachments, channel improvements, bridge and culvert structures, split flow conditions, and floating ice that the model is to include in its analysis.
After the model has been properly defined, the water surface profile analysis can be performed. After the analysis is complete, BOSS RiverCAD can overlay the water surface profile on top of the contour map, showing the extent of the water surface with regard to the ground topography. It will display the computed water surface, critical water surface, and energy grade line elevations on the cross-section grids. In addition, profile grids can be created. Since these various grids are contained within the RiverCAD drawing file, they can be quickly annotated with descriptive notes and drawing details.
BOSS RiverCAD uses drawing layers extensively, storing various entities on their own layers. Drawing layers can be thought of as transparent drafting overlays. RiverCAD allows an unlimited number of drawing layers. Organizing the drawing by using layers allows various elements and components of a drawing (for example, cross-section reach lengths) to be turned ON and OFF, letting you view and plot them separately or in combination.
The BOSS RiverCAD program supports four modules which can be used independently, or in combination, to quickly develop river basin models, compute surface water profiles, and provide unparalleled output of results. These include the HEC-2 Interface Module, HEC-RAS Interface Module, Floodplain Mapping Module, and DEM Interface Module.
The HEC-2 Interface Module provides a graphical CAD interface to the U.S. Army Corps of Engineers industry-standard HEC-2 water surface profile analysis engine. The HEC-2 Interface Module includes the HEC-2 analysis engine, and provides all of the tools to perform HEC-2 water surface profile modeling within CAD. When purchased with the HEC-RAS Interface Module, BOSS RCAD allows the user to quickly switch back and forth between HEC-2 and HEC-RAS analysis models.
The HEC-2 analysis engine is a one-dimensional, steady state, gradually varied flow model. Subcritical and supercritical profiles can be computed separately. The model can account for backwater created by bridges, culverts, weirs, and other structures. The model can be used to evaluate floodway encroachments, identify flood hazard zones, manage floodplains, design and evaluate channel improvements, and determine split flows.
The HEC-RAS Interface module provides a graphical CAD interface to the recently released U.S. Army Corps of Engineers HEC-RAS water surface profile analysis engine. The HEC-RAS Interface Module includes the HEC-RAS analysis engine, and provides all of the tools to perform HEC-RAS water surface profile modeling within CAD. When purchased with the HEC-2 Interface Module, BOSS RiverCAD allows the user to quickly switch back and forth between HEC-RAS and HEC-2 analysis models.
The HEC-RAS analysis engine is nearly identical to the HEC-2 analysis engine. However, HEC-RAS has additional capabilities which HEC-2 does not provide. First, HEC-RAS provides much more sophisticated bridge and culvert modeling capability. For example, HEC-RAS can model multiple bridge and/or culvert opening at a single roadway crossing. HEC-RAS uses the actual bridge opening geometry in its analysis, including the bridge deck, piers, and abutments—not a trapezoidal approximation of the bridge opening as is performed using HEC-2. Culverts can be box, circular, arch, pipe arch, or elliptical in shape, and multiple culverts—of differing size and shape—can be modeled at a single crossing. Also, in cases of roadway weir overflow, the submergence effect is accounted for in high tail-water conditions. Second, HEC-RAS can model subcritical and supercritical mixed flow regimes, as well as the transitions between these regimes. Third, the momentum equation is utilized in situations where the water surface profile is rapidly varied. These situations include mixed flow regime (ie., hydraulic jumps), bridge hydraulics, and river confluences (ie., stream junctions). Finally, HEC-RAS provides additional capabilities, including an alternate sub-area conveyance computational methodology and an automatic Manning roughness calibration routine.
The Floodplain Mapping Module includes a digital terrain modeller to interpolate the edge of water between cross-sections. This allows the user to see—in precise detail—which areas of the topo map are flooded. It can also display shallow flooding areas, using any user-specified depth value. This permits the user to quickly identify possible ineffective flow and flood fringe areas. Color filling and hatching of the flooded areas can be performed automatically. To perform floodplain mapping, either the HEC-2 or HEC-RAS Interface Module must also be purchased.
To provide better visualization of the water surface profile modeling results, the Floodplain Mapping Module can generate contours of flow depth or elevation labels, colored or colour-filled relative to depth or elevation, and highlighted to indicate specific contour intervals. The Floodplain Mapping Module also offers several automated methods of cutting and merging cross-sectional data, thereby enhancing the already powerful cross-section cutting capabilities of BOSS RiverCAD. This gives the user unlimited flexibility—allowing him to input any type of ground data into the program.
The DEM (Digital Elevation Model) Interface Module allows the user to directly import USGS DEM data—either 1:24,000 or 1:250,000 scale maps. The DEM Interface Module automatically senses the DEM data type as it is imported, and multiple maps can be imported and automatically merged. Cross-sections can then be generated from the imported DEM data. USGS DEM data is available from a variety of sources, including BOSS International.
I have a civil engineering background but have never been involved with water flow matters. But it is clear RiverCAD is comprehensive and also quite simple to use. It's all very self-evident actually, at least if you have some understanding of the principles, and I wouldn't expect any untrained people to be doing what RiverCAD supports! The main thing is it automates many otherwise repetitive, laborious and error-prone manual pencil-&-calculator actions, and makes possible many analyses that would otherwise not be justifiable, and allows easy exploration of design options.
So if you are a civil engineer involved in hydraulics and works affecting natural surface water, even if not as a primary activity, then BOSS RiverCAD is well worth a look.
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