Automating HEC-RAS tool

Some years ago, (early 2010) I found a way to break the RAS code and to automate some features of HEC-RAS. Thus, I was able to perform sequential modelling HEC-HMSàHEC-RASàSobek1D2D and to perform uncertainty analysis within cloud (Moya Quiroga et al., 2013). At that time there was no literature about the RAS code, so I had to try several options in the Controller class and find out how they work. In October 2015, “breaking the RAS code” was published (Goodwell, C. 2015) and I hurried into getting my copy (I was among the first ones, so it included a 4 colour pen).

Fig 1. HEC-RAS in sequential modelling (Source: Moya Quiroga et al., 2013)

Documentation in the book gave me important tips and I was able to develop several scripts for automating many pre-processing and post-processing tasks; not only updating parameters but also modifying geometry and post-processing results. 

HEC-RAS used to be a great tool, but now it became wonderful. However, all my scripts work under the console (no graphical user interface GUI). I developed them and I know how to use them. Thus, I decided to include a user interface in order to make more universal tools. Few years ago I released the first version with a graphic user interface GUI (AHYDRA), a tool for automating hydraulic analysis. Debugging and coding takes time, so I released and didn’t improve it. Few months ago I decided to update it and to release new improved version was released. This version includes new features and some bugs were fixed.

New automatization options for HEC-RAS

The first application that I got for this tool was to improve the boundary conditions in HEC-RAS. This  new version automatically updates data and simulates HEC-RAS considering:

·   Downstream boundary conditions (energy slope). Important for analysing the extent of the uncertainties due to BC and to select the best BC for our case.

·   Manning roughness. Important to analyse the range of potential manning roughness. Besides, it allows analysing a spatial variable Manning. For instance, the Manning range is between 0.03-0.04; we can simulate one cross section with 0.03, the next cross section with 0.034 and so on. Thus, we will be able to perform an uncertainty analysis of manning.

·     Upstream discharge boundary condition. Inflow is usually assumed as a fixed value. However, most inflow discharge data are based on steady state stage-discharge curves prone to errors. Thus, we can perform a sensitivity or uncertainty analysis of the inflow.

Fig 2. User interface of AHYDRA

Single and multiple simulations (Monte Carlo).

•  The single simulations option (at the left of the GUI) allows to automate one simulation by changing one value of the mentioned possibilities.
• Besides, this version includes the possibility to perform a Mont Carlo analysis by running several simulations and randomly updating the desired parameter within a user specified range. This option is located on the right side of the GUI.

Rip rap design

The single simulation option also calculates the rip rap size (d50 in SI units) for each cross section, by considering the simulated hydraulic conditions and the USGS rip rap design criterion.

Installaing AHYDRA to automate HEC-RAS

This version includes an installer *.exe. Just double click it and follow the install wizard. After installation AHYDRA will be accessible via desktop and start up menu.

For the free AHYDRA installer fill this form (click here), or scan the QR code.

Scan the QR code with your tablet/smartphone to fill the free AHYDRA request form.

• Automating Manning video
• Automating Inflow video
• Automating boundary condition