Friday, May 8, 2009

Multi-dimensional modeling

Written by Chris Goodell, P.E., D. WRE | WEST Consultants
Copyright © 2009. All rights reserved.

As much as I am an advocate for HEC-RAS modeling, I recognize that there are some cases where you need to go to a multi-dimensional model. I'm not as quick to jump to that level as others I've worked with, I think mostly because there are a lot of quasi-2-d techniques built into RAS that can be used to simulate flood conditions that are dominated by 2- and 3- dimensional flow patterns. However, there have been cases where it is necessary to go multi-dimensional. My best example is a project I was working on that consisted of a flood down a well confined canyon that opened up onto an urban alluvial fan with no defined channel. I tried to work RAS forward and back to get it to work-tons of lateral structures and storage areas, lots of assumed ineffective flow areas, etc., etc., but it just wouldn't happen. I ended up using FLO2D for the alluvial fan portion of the study area and it worked quite well. I've also used RMA-2 and CCHE2D succesfully in other applications. Does anyone out there have other models that have worked well?


  1. Sometimes I use River2D and compare to the results of RAS. Its very nice.

  2. I use CCHE2D for sediment and it's work well