We try to use real projects where possible, but if there is time, we also go online and find free DEM data anywhere on the planet and try to out-engineer each other. I also like to let everyone choose their own location for workshop exercises. Luckily it was a fairly simple shape, so we embedded a 10-kilometre diameter logo into the Bonneville Salt Flats and ran a flood over it. One time I was asked if I could make levees in the shape of a client’s logo. Īlong those same lines, in our HEC-RAS course, doing something completely different can be a bit more fun (and keep attendees awake when it gets to that time of the afternoon on the last day…)įirst, I usually let course participants choose what I should put into the terrain in the demonstration model. (This a variation of the old airplane trick, which has lost its effect over the years.) I’ve found this new approach to be quite effective: we toss the peas into the funnel, and she has a good time trying to keep up.
But if I make the process of eating peas more fun for her, she tends to forget that she hates peas. Here’s my allegory: My daughter hates peas. Putting a regular old culvert or bund into your model may feel a bit mundane so in our courses, I try to take a different approach to make the process a bit more palatable. Follow along or modify your own digital elevation model using the steps in these tutorials: Once we’re at that point, we can adjust the terrain to include any number of features and then compare the results with and without the feature in place. The video instructions below use the free terrain data from the ELVIS server for the Brisbane River in Australia.
In Workshop #1 of our HEC-RAS 5.0 course, we import terrain from the free ELVIS database hosted by Geoscience Australia. Īt the end of Workshop #1, we should have terrain data loaded into RAS Mapper. If you don’t have your own terrain data, you’ll need to grab some first. Coarse-grid (~30 metres) digital elevation models are freely available from SRTM data for the entire planet, but you may want to get a bit more resolution than that. While very handy, these tools do not entirely replace the previous method of using cross sections in a 1D geometry, so we’ve kept the previous tutorials below. Here are a few videos highlighting the new terrain modification tools in HEC-RAS 6.0. New Terrain Modification Tools in HEC-RAS 6.0
Basically, anything you can draw in a series of cross sections – so long as it doesn’t cross over on itself (sorry, no caverns!) – can be added to your terrain. Now if you’d like to try it yourself, you may want to start with something a bit more practical some of the features we build into our terrain in the instructional videos below include:Īre there any other features you’ve added to previous models or that you would like to add to future models? Let me know and I’ll add some examples.
You can use HEC-RAS to modify your terrain in any way you see fit in this model, for example, we use terrain modification to build fences around sheep pens just for fun:
If you would prefer to follow along with the written steps, check out our blog post here. In this article, we’ll walk through the steps of modifying terrain data with HEC-RAS using video tutorials.