Copyright © The RAS Solution 2016. All rights reserved.
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 are happy with,
and now we want to make inundation shapefiles. This is often necessary when
completing dam breach analyses/flood analyses/etc.
There are typically two ways in which flood inundation shapefiles
are created: (1) using HEC-GeoRAS and (2) RAS Mapper. Both methods can face uphill
battles when terrain data begin to exceed 20-30 gigabytes, depending on performance
characteristics of your computer. Below are some typical errors you may see
when trying to create inundation shapefiles with RAS Mapper on very large
terrain.
Figure 1: RAS Mapper Memory Error Messages
There IS a way to
get around this using RAS Mapper. The first thing you’ll need to do is
