McBreach Probabilistic Dam Breach Modeling – Free Webinar

ICEWaRM will be hosting this free webinar where I’ll be discussing the software program McBreach and its application to probabilistic dam breach modeling.  Come join in!  Please note the the webinar start time for your particular time zone.  Starts at 10:30 AM local Sydney Australia time on Wednesday, Nov 6th.  That is 3:30 PM on Tuesday, Nov […]

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Terrain modification and direct rainfall: video walk-through

Terrain Modification Two previous blog posts have addressed terrain modification in HEC-RAS (the December 2014 article entitled Including Channel Bathymetry into your Terrain and the June 2015 article entitled Lifting Terrain in HEC-RAS 5.0). These have been some of the most popular posts to date, each having generated almost 10,000 views over the years! Interchangeably referred to […]

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Rating Curves for Dams

Version 5 of HEC-RAS allows the use of rating curves for inline structures (and lateral structures).  Rating curves can be added through the Outlet RC feature in the inline structure editor.  Inline structure rating curves can be useful for evaluating the impacts of structures, such as labyrinth dams, where it may be difficult to correctly […]

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Using User-Defined Curves for Gates

HEC-RAS allows for four different gate types that will compute the stage-discharge relationship of that gate for you based on the physical size/shape of the gate and a few empirical coefficients:  Sluice Gates, Radial Gates, Overflow Gates (closed top) and Overflow Gates (open air).  However, sometimes the built-in gate types don’t quite fit the gate […]

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“Using HEC-RAS for Dam Break Studies”

HEC recently published a new training document called “Using HEC-RAS for Dam Break Studies”.  Written by Gary Brunner, P.E., D.WRE, it is an easy to follow guide for performing Dam Break simulations in HEC-RAS. It covers topics like: Which routing technique to use to route flows through your reservoir (Dynamic or Level Pool-although I wish […]

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Flow spike after peak of dam breach floodwave.

Just ran into an interesting phenomenon.  I was running a dam breach model with fairly typical breach parameters and piping failure mode.  After the peak of the breach hydrograph, there appeared a mysterious “spike” as shown in the figure below. This happens to be right at the same time the flow through the developing breach […]

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