Hello All,
I am a HEC-RAS beginner attempting to model a dam breach scenario.
I would really appreciate any advice on improving the precision and validity of my results. I have attached the Google drive link below which directs to my project for anyone willing to offer a helping hand.
https://drive.google.com/open?id=0B9sU1ovwalxSMDZCWGtUemNDeGM&authuser=0
I am currently using a normal depth assumption for the downstream boundary condition and a Glacial lake outburst flood (GLOF) hydrograph as the upstream boundary condition. (I have the data to potentially use tidal rating curve as downstream boundary curve).
I have modeled the dam as an inline structure and set the failure time to the corresponding time where the hydrograph peaks which theoretically should produce the largest possible flood. I have no experience in modelling dams or dam breaches and any suggestions on better ways to model this more realistically and effectively would be of great help.
I have tweaked HTAB parameters, increased cross sections and increased levees which were being overtopped which created a stable unsteady flow run. This produced a maximum water surface error of 0.310 metres. Upstream of the dam the rating curves seem to indicate instability in numerical results violently spiking which I do not know the cause or a solution to resolve this issue.
Again any advice or help would be greatly appreciated.
Thank in Advance!