New HEC-RAS v 5.0.4

A new version of HEC-RAS was released; HEC-RAS 5.0.4. The first question to HEC-RAS user's is What are the main improvements of this version?

Actually, there are several improvements. Moreover, considering the software versioning standards, I think it would have been better to call it version 5.1. I will not go into the detail of all the improvements (the release notes is a 19 pages document), but I will summarize the most important ones.

●       Computational speed. Computational speed is crucial in selecting a 2D model. I remember my first experience with HEC-RAS 5 beta took several days to perform a simulation; that same simulation took just about 2 hours using other models. Fortunately, HEC-RAS has been improving its computational speed. This new version has a fully parallelized engine that doubles the computational speed. If your previous simulation required X hours, with this new version it will only require 0.5 X hours.

●       Ras Mapper tools. This one is a major improvement. Previous version still required ArcGIS and GeoRAS for preparing geometric data, especially for 1D cross sections and 1D profiles. This new version includes full GIS geometric processing capabilities. This video shows the creation of a 1D river geometry with the new Ras Mapper.

●       2D nested mesh. Previous version performed 2D simulations on a nearly regular non staggered grid. That means the 2D DX was the same for all the grid. The new version allows to refine the grid at specific locations. Hence, a coarse grid can be used for big floodplains, while a more refined grid can be used for particular areas requiring more detail.

●       More sediment options. New linear scaling factors and granulometry options are available

●       64 bit processor. Most users may not be deep into computer science and may neglect the importance of this improvement. Let me tell you that this is an important improvement with BIG benefits. It allows working with bigger data files and faster processing. You will easily realize this benefits when working with the 2D; you will see how the mouse movements and the clicks are faster and your work is more comfortable.

Image 1. Print screen from the video showing 1D creation with the new RasMapper

Nevertheless, there is one disadvantage that you have to consider before using this new version. Although this 5.0.4 version is compatible with previous versions, previous version are not compatible with models saved under 5.0.4 version.

As I you can see, this new version is not limited just to fixing bugs. It has important add-ons and improvements. Therefore, considering the software versioning standards, I consider that it could have been  more appropriate to call it version 5.1.