Center for Spatial Analysis Technologies
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During October 2000 the flood
project team began work on revising available DEM’s (from NMD) by
topographic quadrangle for the Flint River Basin in the Montezuma,
Georgia area as indicated in figure 1.
The revision is done by digitizing topographic contours from
7.5 minute topographic maps, gridding the area to suitable resolution,
and preparing new DEM’s for each map.
The new DEM’s were inserted into the basinwide DEM,
constructed earlier. The initial DEM revision work, as figure 1 shows, was in the Montezuma, Georgia area along the mainstem of the Flint River. The October 2000 flood inundation model indicated no flooding for the 100 year floodplain, as shown in figure 2. The revised flood inundation model run (November 2000) produced a new 100 year floodplain for the Montezuma vicinity, as shown in figure 3. The improved floodplain (figure 3) illustrates the importance of completing the process of DEM revision to produce a regionally accurate and consistent DEM for the river basin prior to beginning any comparative, qualitative analysis. The DEM revision work will be shared with NMD by the flood team and the Georgia Tech GIS Clearinghouse (GTCH) digital orthophotography team which is working on an active and complementary (USGS cooperative) project to prepare color DOQs for the state of Georgia. These DOQ’s will aid the flood team with the planned future flood inundation visualization capabilities. The ongoing liaison with NMD is needed to improve the process of DEM development in order to begin the organized support of hydrologic applications, such as flood inundation modeling. The plan is to begin to establish and to refine the process using the DEM’s of the Flint River Basin. NMD has offered to partner with the state of Georgia to improve available DEM’s. The flood team also prepared a Power Point presentation to be used by project staff to brief CINDI and cooperative agencies on preliminary research results, the DEM revision process and future plans, such as for quantitative, comparative analysis |
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Figure 1: Status of DEM revision in the Flint River Basin, Georgia |
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Figure 2: Map of the 100 year floodplain model (October 2000) in the vicinity of Montezuma, Georgia |
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Figure 3: Map of the revised 100 year floodplain model (November 2000) in the vicinity of Montezuma, Georgia |
U.S. Department of the Interior |
U.S. Geological Survey
URL: http://csat.er.usgs.gov/cindi/oct2000.html
Page Contact Information: webmaster-ga@usgs.gov
Page Last Modified: Tuesday, 23-May-2006 10:13:49 EDT
