Table 6. Data elements for metadata files.
Identification section
Projection information
Data custodian information Source information
Data set identity
Grid coordinate system
Contact organization
Source name
Theme keywords
UTM zone number
Contact person
Bibliographic reference
Data set description
Horizontal datum
Contact mailing address
Source scale
Data structure
Ellipsoid
Contact telephone
Creator of source
Data set extent
Coordinate precision
Contact E-mail
Data set history
Transfer format
Custodial liability
Metadata reference section
Metadata revision date
that for the Midwest flooding, is being developed
the elements listed in Table 6. These elements de-
at the RSGISC for coastal counties where hurri-
scribe data contents, origin, projection, processing
cane activity has been historically high. Similar
history and a point of contact. Copies of the meta-
databases need to be developed for earthquake
data files can be found in Appendix D.
prone areas and areas where the potential of hu-
The metadata elements included in the file were
man-induced disasters, such as nuclear power
derived from the draft of the spatial metadata
plant accidents, is high. These spatial databases
standard developed for the National Geospatial
will allow rapid response and expand the focus
Data Clearinghouse by the Federal Geographic
on additional data needs during the recovery
Data Committee (FGDC 1992). The draft, revised 23
stages.
July 1993, can be obtained over the Internet from
The Landsat and SPOT data are of significant
the anonymous FTP site waisqvarsa.er.usgs.gov
value when they can be obtained, but also have
(130.11.51.187) using anonymous as both the user
limitations. Specifically, Landsat data were avail-
name and password. The file is located in the wais/
able as frequently as every 8 days when both
docs directory and is titled metadata.893.text.
Landsats 4 and 5 were operational. However,
Landsat 4 was on standby status during the 1993
DISCUSSION AND RECOMMENDATIONS
flood. Additionally, both satellites have only pas-
sive sensing systems and thus cannot image in
The 1990 TIGER/Line data were released in the
the visible or near infrared when it is dark and
end of 1993. The TIGER/Line data in the current
cannot image through clouds. The ERS-1 SAR
spatial database are based on the 1:100,000-scale
has day, night and all-weather capability and re-
maps and the Census Bureau's 1980 GBF/DIME
visits every 35 days. Because of its larger swath
files and, hence, do not reflect changes since the
width, there is enough overlap that images can be
1980 Census. These data could be added to the
obtained every 7 days. However, none of these
spatial database to provide more recent data.
commercial satellites assures that an image can
Disasters involving large geographic areas or
be obtained within even several days of when it
large numbers of people necessarily involve multi-
might be required.
ple government agencies. As has been noted in the
The optimal approach to obtaining imagery
publications of the FGDC dealing with a proposed
during emergencies is to use an all-weather, day
National Spatial Data Infrastructure (NSDI), it is
and night capable system that could be fielded on
necessary that all agencies collecting data, particu-
the short notice required for rapid response. Fur-
larly those collecting data with Federal funding,
thermore, the ideal system should be able to do
minimize duplication of data collection efforts,
real-time deconvolution, with processed data de-
maximize use of the data for multiple purposes,
livered either upon landing or telemetered to the
and coordinate to ensure that knowledge of the ex-
ground while in flight. Airborne SAR with low
isting data is widely accessible (NRC 1993). The
depression angles and an integrated Global Posi-
NSDI is working vigorously to achieve these goals.
tioning Systems (GPS) for rectification is one such
Considerable effort is being expended by the
system. During the Midwest flooding, the use of
Corps of Engineers, as well as by other agencies, to
this was evaluated as it was available for over-
assure that responsible actions are being taken in
flights during 4 days. However, because of the
the collection and sharing of flood-related data.
large area that was flooded, the peak flow oc-
The development of databases for emergency
curred over more than 30 days. Additionally, the
preparedness will aid in response and recovery ef-
cost of rapid data processing to meet National
forts for other natural and human-induced disas-
Map Standards accuracy for 1:100,000 scale maps
ters. For example, a hurricane database, similar to
12
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