Model a simple flood event

[mw21]

I'm interested in modeling a basic - simple flood event caused by heavy rainfall. Essentially looking at any low lying areas that would collect rain water and pool. I've been playing around with GSSHA model - but wondering if it is the best or simplest way to get the results I'm looking for. I believe I have all the data needed to run the model - but the area I am trying to model is quit large and am wondering if there is another method within WMS that would better suit my needs?

Thanks for your help!

[Clark Barlow]

GSSHA sounds like the perfect model for this application. The model setup for this scenario should be fairly simple, even for a large domain. All of our other models are 1D lumped parameter models so you'd have to subdivide the watershed and pass peak flows into a hydraulic model to determine flooding. The GSSHA tutorials should walk you through the model setup, so even if you've never used the model before it should be pretty easy to do.

Hope this helps.

[mw21]

Thanks for the input - I appreciate it! I've been looking through the tutorials and it does seem pretty straight forward... One other question I have - I've been running into some situations where I'm ending up with many 0's or -1's in my 2D Grids. Is there a quick way to convert those 0's and '1's into different values? Kind of like a find and replace (ex. replace all 0's with 3's...)?

Thanks again!

[Clark Barlow]

There isn't a way to do this from within the interface. You could do it in a text editor though. When you save a GSSHA project, your 2d grids (index maps) get stored in .idx files. There should be one .idx file for each index map. You could open this in Wordpad and do a search and replace.

Of course, the best practice is to figure out why you're getting 0's an 1's in the first place. If your shapefile is incomplete or you don't have data for the entire domain, it's probably best to fix the data or get a larger dataset.

-Clark

[mw21]

Thanks again!!!!!