The United States Army Corps of Engineers, Kansas City District published the 1994 hydrographic survey as a series of 182 large-scale maps, each characterizing, on average, between 2-4 miles of the river.  The Kansas City District provided the Columbia Environmental Research Center with georeferenced Microstation DGN files. They were processed as follows:

1. The DGN files were converted to ArcView shapefiles.

2. The shapefiles were edited to remove all cartographic features not representing the actual floodplain condition. 

3. The length of vertices was calculated.  Line "entities" with a length less than 25-feet were selected and removed.  They represented symbol fills.

4. The Multi-part shapefiles were converted to single part shapefiles (polyline).

5. The shapefiles were generalized to a minimum vertex length of 2.5 feet. This reduced the number of vertices by 80 to 90-percent.

6. The shapefiles were reprojected from Missouri State Plane to UTM, Zone 15, NAD83, Meters.

7. The shapefiles were converted to DXF files.

The River Studies Station uses these DXF files in conjunction with navigation software to plan and execute river habitat mapping activities. Because file size is inversely related to screen refresh rates, it is important to keep them as small as possible. This was accomplished by eliminating cartographic elements, symbol fills and the number of vertices used to characterize features.