The River Mechanics models and tools were originally developed by Dr. Danny Fread and Janice Sylvestre at the National Weather Service (NWS) from 1974 through 2005.  Although they are no longer supported by NWS, the RiverMechanics Group is committed to enhancing and maintaining the following: BREACH, SMPDBK, FLDWAV, FLDAT, and FLDVIEW.

Featured Application:   BRCH-J

The Breach Erosion Model (BRCH) produces the size and shape of the dam breach opening, the time of formation, the outflow hydrograph, and the tailwater elevation hydrograph of an earthen dam.  The model is physically based on the principles of hydraulics, sediment transport, soil mechanics, the geometric and material properties of the dam, and the reservoir properties (storage volume, spillway characteristics, and the time-dependent reservoir inflow rate).  The dam may be either man-made or naturally formed as a consequence of a landslide.  The critical material properties of the dam are the internal friction angle, cohesive strength, and average grain size diameter (D50 ).

These parameters may be used in the River Mechanics hydraulic models (i.e., FLDWAVE, SDB-J) to model the breach outflow and route it through the river downstream.  BRCH is a FORTRAN application originally developed in 1984 with the last NWS revision in 1999. The current version (2018) is not affiliated with NWS.

A Java GUI (BRCH-J)  is used to create or read in an input data file, run it through the BRCH application, display an animation of the dam breach formation, and display the hydrographs/rating curve graphically.  The animation algorithm has been modified to better represent the assumptions made in the BRCH model.  An example of the BRCH-J animation of a simulated piping failure of the 1976 Teton Dam breach is below.




   is not affiliated with the National Weather Service

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