Breach Inundation Analysis

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Breach Inundation Analysis

Brent Chesnut
I am working on a Breach Analysis and need to create an inundation map. The breach releases into a much larger river floodplain. The inundation map needs to outline the area that will be flooded up to the point where the breach wave intersects with the 100 year flood elevation. In other words, I need to map the point where the two elevations meet. I am trying to show the difference in depth between two results but can figure out how. I think that would give me the limits I am looking for. Does anyone have ideas or ran into this before?
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Re: Breach Inundation Analysis

cameron
The 100yr floodplain should be available in GIS format as part of the NFHL database. All you should need to do is clip your breach inundation map to the 100yr floodplain.
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Re: Breach Inundation Analysis

Brent Chesnut
The inundation area is considered the point at which the breach wave intersects with the 100-year flood elevation. This is not necessarily the edge of the floodplain because the breach wave could be a couple feet higher than the 100-year flood elevation. Thanks for you reply though.
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Re: Breach Inundation Analysis

cameron
What I would do then is create a wse raster of the 100yr floodplain and subtract it from the the breach wse raster. The zero contour would be the edge of where they meet.