database is in UTM zones 15 and 16. The maps
SPATIAL DATABASE DISTRIBUTION
were created in UTM zone 15 based on NAD27.
The spatial database for the Midwest flooding
The scale of the 20,000- 20,000-m maps was not
has been prepared for distribution on either mag-
exactly 1:133,333 for all the maps. Exact guidelines
netic tapes or via the Internet. The seven-river da-
had not yet been established for zooming in on
tabase is approximately 400 Mbytes in size. All of
the 20,000- 20,000-m regions and, consequently,
the data have been projected to the correct UTM
this initial notebook did not have a consistent map
zone and the datum converted to the NAD83, rec-
scale. This was rectified for the map notebooks
tifying the problem of mixed datums that was
produced for the remaining rivers.
present when the maps were produced.
The Mississippi River maps were the only ones
that included inundation data, which were pro-
Distribution formats
vided be CETEC.
The spatial database for the midwest flooding
has been prepared for distribution. The data were
Missouri River
written in two distribution formats to allow them
The Missouri River database is located in UTM
to be imported into a variety of GIS's: 1) ARC/
zones 14 and 15. The maps created were in UTM
INFO Export 6.1 and 2) DLG-3 optional. Metadata
zone 15, based on NAD83 for all counties except
files were created to accompany the data (see next
those in Nebraska, which were in NAD27 (see
section ).
footnote, p. 7). There were no inundation data
The conversion to ARC/INFO Export format
available at the time of production of these maps,
maintains all information associated with the cov-
thus they serve as base maps.
erages in the Feature Attribute Tables (FAT).
These FATs have a spreadsheet format where
Des Moines River
each occurrence of the feature (e.g., polygon, arc,
The maps created for the Des Moines River
point) in the map occupies a row and the descrip-
were all in UTM zone 15, based on NAD83 (see
tive elements of the feature occupy the columns.
footnote, p. 7). There were no inundation data
The descriptive elements, such as length and
available at the time of production of these maps.
name, are called "items."
In the conversion to DLG-3 optional distribu-
Kansas River
tion format, only information contained in integer
The reach of the Kansas River mapped because
item pairs titled "Majorn" and "Minorn," where n
of flooding is in UTM zones 14 and 15, based on
= 1, 2, 3, ..., are converted to the new format. To
NAD83 (see footnote, p. 7). There were no inun-
allow conversion of the Census Feature Class
dation data available at the time of production of
Codes (CFCC) for the roads, hydrography and
these maps.
railways data derived from TIGER/Line files and
the county names in the counties coverage, modi-
Republican River
fications were made to the coverages as described
The reach of the Republican River mapped is in
in Appendix C. To describe this process briefly,
UTM zone 14. The maps were based on NAD83
Major1 and Minor1 items were added to the FATs
for all counties except the Nebraska counties,
and integers representing the CFCC value or
which were based on NAD27 (see footnote, p. 7).
county name were assigned to the Major1 item. A
There were no inundation data available at the
description of the Major1 values was then added
time of production of these maps.
to the DLG versions of the metadata files.
Grand River
Metadata
The maps that were produced for the Grand
Metadata, or data about data, were created and
River were in UTM zone 15, based on NAD83 (see
placed in text files for distribution with the spatial
footnote, p. 7). There were no inundation data
database. This was done to help other users to
available at the time of production of these maps.
understand the data content and to ensure ap-
propriate use based on the accuracy of the data,
Illinois River
defined by factors such as resolution and cre-
The maps that were produced for the Illinois
ation date. Files were created for each distribu-
River were in UTM zone 16, based on NAD27.
tion format and UTM zone for the seven river
There were no inundation data available at the
databases and each distribution format for the
time of production of these maps.
inundation databases. Contained in each file are
11
Previous Page
