|
FLOOD PLAIN DEVELOPMENT STUDY
07/27/2003
HOW THE STUDY WAS DONE
The Post-Dispatch hired Saint Mary's University of Minnesota, a longtime leader in study of the upper Mississippi River, to analyze flood plain development in the states affected by the Flood of 1993.
The study examined changes in the past decade in the major river flood plains of Illinois, Iowa, Kansas, Minnesota, Missouri, Nebraska and Wisconsin. Researchers compared pre-flood satellite images with current satellite images of the same areas, focusing on land in and around metropolitan centers.
Researchers visually identified areas where natural land cover, such as fields or trees, had been converted to buildings, parking lots, highways and other impervious surfaces.
RELATED LINKS:
Full series in our special report
Flood timeline, with links to archival photos and stories
<LI><A HREF="/stltoday/news/special/flood93.nsf/C4CCE258128EB3628625676F001EE75C#Graphics" CLASS="related">Graphics: How a levee works, riverfront development and more</A>
<LI><A HREF="/stltoday/news/special/flood93.nsf/C4CCE258128EB3628625676F001EE75C#ArchivalVideo" CLASS="related">Archival video, courtesy KTVI Fox 2</A>
<LI><A HREF="/stltoday/news/special/flood93.nsf/C4CCE258128EB3628625676F001EE75C#PhotoGalleries" CLASS="related">Photo galleries from the '93 flood (including readers' photos)</A>
<LI><A HREF="/stltoday/news/special/flood93.nsf/C4CCE258128EB3628625676F001EE75C#Outsidesources" CLASS="related">Related links to outside sources</A>
<LI><A HREF="http://www.stltoday.com/current" CLASS="related">Discuss the series in our forum</A>
</td><td bgcolor="ffffff" class="story"> </td></tr><tr></tr></table>]
The study looked at areas that were under water during the flood, as well as the historic 500-year flood plain from bluff to bluff. Areas protected by levees were included in this analysis.
Saint Mary's used definitions of the flood extent and the flood plain created by the Scientific Assessment and Strategy Team, an interagency government team appointed by the White House to study the flood. The SAST data did not include North Dakota or South Dakota, where most damage was caused by oversaturated soil rather than by river flooding.
Saint Mary's researchers also used U.S. Census Bureau data to determine population and housing unit changes in the flood plain and flooded areas from 1990 to 2000. The researchers chose census blocks that had a geographical center point within the flood plain. These figures should be interpreted as estimates, because census block outlines don't line up perfectly with flood plain boundaries.
WHO DID THE STUDY
St. Mary's University of Minnesota, based in Winona, Minn., has been a leader in the study of the upper Mississippi River since the 1930s. The Mississippi River Research Consortium was founded on the St. Mary's campus.
Today, the university's GeoSpatial Services center manages the Mississippi River Stakeholder Network, a group of farmers, conservationists, river users and public officials.
GeoSpatial Services uses geographic information system data to conduct research for private and public entities, including wetland mapping for the U.S. Fish and Wildlife Service.
For more information, visit www.gis.smumn.edu
Co-authors of the study:
1.) Barry Drazkowski
Director, GeoSpatial Services, Department of Resource Analysis.
Drazkowski specializes in using GIS data to analyze the ecology of large river systems. He previously worked for the U.S. Geological Survey and for the Army Corps of Engineers in the fields of biology and environmental planning.
2.) James D. Hipple, Ph.D.
Associate Professor, director of GIS master's program on the Twin Cities Campus.
Hipple specializes in the use of satellite imaging systems for environmental analysis. He previously worked as a private consultant and as an assistant professor of geography at the University of Missouri at Columbia.
3.) Patrick Thorsell
GIS Analyst/Programmer
Thorsell's duties include GIS programming, database management, project development, Web site development, and data development. Thorsell holds a master's degree in resource analysis.
HIGHLIGHTS OF THE STUDY
Missouri has developed more flood plain than any other state affected by the Flood of 1993. Buildings, parking lots and highways now cover more than 4,200 acres of flood plain, most of which was under water 10 years ago.
Nebraska was next with 2,224 acres, most of it residential development on land that didn't flood in '93.
Illinois, Iowa and Wisconsin had 1,000 to 2,000 acres of development, and Kansas and Minnesota had fewer than 1,000.
The St. Louis Area
The St. Louis area accounted for 90 percent of new flood plain development in Missouri. Greater St. Louis had about 3,870 acres of new development, while the Kansas City area had 405 acres.
Major flood plain developments in the St. Louis area were found in Chesterfield, Maryland Heights, Riverport, Earth City, Hazelwood, St. Charles and St. Peters. Highway construction, especially the Page Avenue Extension and Highway 370, accounted for more than 500 acres of development.
Illinois
In Illinois, most new development took place in Metro East areas protected by 500-year levees and flood walls. Madison and St. Clair counties accounted for 90 percent of the new development, with projects such as the Gateway International Raceway in Madison and Gateway Commerce Center in Edwardsville.
Overall
Overall, the study detected more than 12,000 acres of development in the Midwest. Of this, about 6,630 acres were commercial and industrial, 2,557 acres were residential, and 2,327 acres were highways and interchanges.
All residential development happened on land that had not been flooded in '93, except for one subdivision in Wood River, where some internal flooding occurred. Most of the new houses were in the 500-year flood plain, not the 100-year flood plain.
Census data shows that 28,000 houses have been built on land that was under water in 1993, and a total of 84,500 houses have been built in the historic flood plain.
Buyouts
Buyouts have moved some people from the riskiest part of the flood plain, but flood plain population is growing overall. In 2000, 1.1 million people lived in the historic flood plain in the seven states, a 21 percent increase in population since 1990. Most of these people lived behind levees and would be in danger if the structures failed.
|
|
 |
|
