Hello,
I am working with several floodplains that are in polygon zm format and I'm trying to figure out how to get a floodplain that is in between stages. The topography is highly variable where a jump from one stage to the next would produce a nonuniform increase in area. That is to say, a 1 ft increase in flood stage might flood a large tract of land in one area but extremely little area in another area.
There are several flood stages (i.e. 7 ft, 8 ft, 9 ft, etc.) that were created from a hydrologic model. The original model used to create them is not available anymore, but I would like to essentially produce sub-stages (i.e. 7.5 ft, 8.5 ft, etc.). They don't need to be 100% accurate, but just something close. Creating a layer where the perimeter of the polygon is the midpoint of the above and below layer would be just fine (7.5 ft perimeter would be the midpoint of 7 ft and 8 ft perimeters). Is there a simple way to do this?
My thought was to convert the polygon zm file to a topo and then create a 3d raster from that, but it doesn't appear to be possible. Any help would be greatly appreciated.
Nearly forgot to mention that I'm working with ArcGIS 9.3.1 ArcInfo with all the basic extensions (it's for a University).
Thanks,
Phil W
