We often have to deal with very large models covering hundreds of river miles. The terrain data associated with these models can be equally massive, which can cause memory/processor issues when trying to delineate inundation maps. This post is not concerned with pre-processing our model geometry. Instead, we have a completed model with results we […]
HEC-RAS 5.0 now provides a tool for quickly re-projecting model geometry within RAS. It is accessible from the main RAS interface under the Options menu…Convert Horizontal Coordinate Systems. From this window, the user must select the Current Project Spatial Reference System and the Destination Project Spatial Reference System by loading the appropriate projection file (*.prj) […]
Your computational mesh is what will allow you to do 2D modeling in HEC-RAS. Think of a mesh as a net that you drape over your terrain. The continuous properties of the “infinite” terrain are then discretized onto the mesh so that computations can be made over a finite domain. Here in the geometry editor, […]
The last post on XS interpolation gave an overview for reasons cross section interpolation may be necessary and a detailed description of Interpolation Option A: “Within a Reach”. http://hecrasmodel.blogspot.com/2014/05/exploring-hec-ras-xs-interpolation.html This post will cover Option B: “Between 2 XS’s”. Between 2 XS’s simply means HEC-RAS will interpolate cross sections ONLY between two selected “non-interpolated” cross sections. […]
As most HEC-RAS users quickly find out, there are some convenient tools for managing your view in an HEC-RAS graphic. Zoom In, Zoom Previous, Zoom Out, Full Plot, and Pan. These generally work how you think they should and are available on all of the HEC-RAS graphics including the geometry schematic, profile plots, cross section […]
I’m starting a new series called “Exploring HEC-RAS”. Each post will discuss a feature in the menu items, starting with the Tools menu item in the Geometry Schematic. Today’s topic is “XS Interpolation Within a Reach”. There are two options for interpolating cross sections in HEC-RAS: “Within a Reach…”, let’s call this Option A, and […]
I don’t think you’ll find this anywhere in the manuals, but HEC-RAS has a very convenient tool for measuring lengths and slopes in the Geometry window and just about any graphical plot. It only works in the geometry window if your RAS model is georeferenced, as it measures distances based on coordinates. However, in the […]
As RAS model development is done more and more through GIS, using the HEC-GeoRAS extension, cross section point filtering is becoming a standard part of the HEC-RAS model development exercise. It’s not too uncommon for a model created in GIS to have multiple hundreds of cross section station elevation points. This is normally not a […]
Editing the positioning of your geometry in HEC-RAS can sometimes be a pain, especially with large systems. This tip will show you how to quickly (and easily!) remove sections of a reach. If you import reach stream lines through ArcGIS, or a similar program, your schematic may look similar to the figure below. In this […]