Post-Processing: Creating Inundation Maps with very Large Terrain

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 […]

Read More

The Advanced Hydrologic Prediction Service for Chehalis Washington

A great example of where flood inundation maps and accessible flood warning systems can help a community prepare for floods.       Contact:               Brent Bower                                                                      FOR IMMEDIATE RELEASE  206-526-6095 x228                                                           December 15, 2015                                 Flood Inundation Maps to Enhance Flood Forecasts for the Chehalis River People living along the Chehalis River have […]

Read More

The Projection File

RAS Mapper is a window in HEC-RAS that allows you to preprocess 2D areas, map results, and manage background images.  In future versions of HEC-RAS, RAS Mapper will become more and more prevalent in our HEC-RAS modeling experience.  As I understand it, eventually RAS Mapper and the geometry editor window may merge to form the […]

Read More

2D Mesh “Leaking”

To follow up my post on fragmented inundation, I want to highlight another 2D mesh issue we should all be aware of.  Unlike fragmented inundation, which is an artifact of how HEC-RAS discretizes the 2D domain and the way it maps the results, Leaking is a result of terrain features not aligning with cell faces […]

Read More

2D Troubleshooting – Fragmented Inundation

(Initial post 19 Feb., 2015.  Updated 20 Feb., 2015).  I continue to be more and more impressed with how user-friendly and robust the new 2D feature is in HEC-RAS.  However, there are some issues to be aware of, particularly in how results are mapped.  I want to take the next two blog posts to highlight […]

Read More

HEC-RAS Model with 2D Mesh Only.

There have been many questions lately about whether HEC-RAS 5.0 can perform a simulation with ONLY a 2D mesh (i.e. no cross sections).  The answer is yes.  In fact, in many ways it’s a lot easier.  In this example, the standard Muncie project offered by the Hydrologic Engineering Center has been converted first to SI […]

Read More

Web Imagery for RAS Mapper in Version 5.0

There are a lot of new features in Version 5.0.  We’ve discussed quite a bit the new two-dimensional capabilities.  But a real pleasant surprise for me was how great the new RAS Mapper is.  I’m going to try to highlight some of these new Mapper features over the next few months, but in this post […]

Read More

Dam Failure of a Coal Slurry Impoundment

I was recently asked my opinion on a good way to model the following dam breach event: “I …recently completed three consulting projects where I simulated the breach of three proposed coal slurry impoundments.  The permitting agency required a RAS model of an “instantaneous” hypothetical breach (over full depth, almost 80 ft for one of […]

Read More