Trouble with interpolation and  flood innundation mapping

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01-16-2012 08:57 AM
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BenKratzer
New Contributor
Hello,
I'm a student trying to work on a project and i'm running into an issue I'm hoping someone might have an idea to get around. I'm trying to create some flood inundation maps for a specific stream. I'm doing this by simply getting the stage on specific dates from the USGS gage information at multiple USGS gages. I also know the stage-discharge relation at a couple of points along the stretch of river I'm interested in, so I'm able to determine the state at these points also. With these 5 known points I know the water surface elevation, and I am hoping that I can interpolate the water surface elevation along the river between the 5 known points. What I hoped to do next was to simply subtract the interpolated water surface elevation form the land surface elevation to determine the area that is inundated during a flood. The problem I'm running into is that the Geostatistical Analysis layer I end up with after performing the interpolation is not not wide enough to cover my flood plain (see the attached image). Does anyone know how I can expand the horizontal extent of the GA layer that is created as a result of interpolation? is this possible? Any feedback would be appreciated.
[ATTACH=CONFIG]11199[/ATTACH]

Thanks for the help,
Ben
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SolomonVimal
New Contributor
I'm trying to work with a similar problem. Have you arrived at any useful alternative yet?
Please mail me at solomon@civil.iisc.ernet.in

Thanks,
Solomon.
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neilo_brien
New Contributor
Get a GOOD dem as your base, USGS, SRTM, LIDAR etc.
Get a lake polygons
River Lines

Test elevations on water ways verses land elevations Look for Noise i.e. SRTM/LIDAR hitting a cluster of building this needs to be dealt with or understood. If there is alot of them then you need to make a decision igor or deal with by averaging pixel around or deleteing those pixels and "growing" in new ones from around it.
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