So you want to control HEC-RAS from a external program. Perhaps, you have a lot of plans to run and want to run in batch mode. Maybe you wish to run HEC-RAS, evaluate the results, make some changes, and rerun HEC-RAS-all automatically, on its own, while you’re at home with the family. The good news […]
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 […]
If you have built enough HEC-RAS models, you’ve probably discovered that having data in different vertical datums is a bit of a pain. RAS lets you adjust the vertical datum of individual cross sections (under “Geometric Data”, “Cross Section”, “Options”, “Adjust Elevations”) or portions of the model (“Geometric Data”, “Tools”, “Datum Adjustment”). However, I have […]
Lateral structures can be used in HEC-RAS to transfer flow from a river/reach to a storage area, or to another river/reach. With the coming release of HEC-RAS with 2D capabilities (estimated beta release January/February 2014), you’ll be able to hook a river/reach to a 2-D area using a lateral structure. Although its primary function in […]
I am working on a dam breach project where I’m trying to simplify a complicated model with dozens of tributaries and storage areas. In the process, I’m converting a few tributaries into storage areas (which are surrounded by other storage areas). For example, I want to convert the reach below (from 5.43 to 0.55) to […]
One of the most frustrating aspects of unsteady HEC-RAS modeling can be the model stabilization process. You know, you’ve gone to great lengths collecting the best survey/topo data and solid hydrology. Then you’ve painstakingly spent hours…possibly days entered all of that data only to find that once you press the “Compute” button, the model crashes. […]
I just received this question about downstream boundaries in HEC-RAS, and thought it would make a nice post here on RASModel.com. “…regarding the boundary condition, if I use critical depth instead of normal depth will it be unacceptable? When choosing the normal depth I need to enter a slope, can i use just one slope […]
This is a great presentation put together by Mr. Steven Piper of the Hydrologic Engineering Center that discusses in detail the use of “Rules” at inline structures. Dr. Michael Gee forwarded this presentation to me after seeing some discussion on the forum about the use of Rules for inline structures. Thanks for the suggestion Dr. […]
I’m a big proponent of checking flow consistency in your results. Anyone who has taken a RAS class from me has heard me go on about Standard Table 2 and the benefits of maintaining a consistent distribution of flow not only between sub sections (left overbank, main channel, right overbank) in a cross section, but […]
The first version of HEC-RAS I ever used was Version 2.2 back in 1999. There are very few of us who actually used the first version of HEC-RAS which came out in 1995, but for those who do remember that, here’s an image showing the very first HEC-RAS Version 1.0: Version 1 was very simple, […]
UPDATE. HEC has asked that I no longer distribute HEC-RAS 4.2 with 2D Alpha. Their purpose for releasing this alpha version is to get constructive feedback so that they can improve its functionality and efficiency; and to minimize bugs before the offical beta release-not to be critically compared to other established 2D software packages…yet. So far, […]
First, let me apologize for the downtime with the previous HEC-RAS Bloggery Forum. There were some issues with the forum hosting service. Unfortunately, I lost all of the previous posts and comments. The upside is that now I have much more control over content/storage. Please have a look at the new forum and post comments/questions/replies. […]