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UPPER MISSISSPI RIVER POST FLOOD OF 1993 FLOODPLAIN DEVELOPMENT ANALYSIS
The Challenge: During the summer of 1993 heavy rain falls, saturated soils, loss of wetlands, and floodplain reductions from levee construction all contributed to one of the most cataclysmic floods of record in the Midwest. The Mississippi River experienced what was termed a "500 year flood" on an extended stretch of the river from southern Iowa to southern Illinois. Businesses, farms, communities, and families living their lives behind levees the government said would protect them from flooding, realized devastating losses of property, their way of life, and their sense of security for what they worked so hard to build. Environmnetal & GeoSpatial Services provided the St. Louis Post Dispatch with floodplain analysis, data proven reports, and information to support the recommendations for future construction and evaluation. The Solution: GeoSpatial Services completed the most comprehensive, basin-wide, floodplain evaluation since the Scientific Assessment and Strategy Team (SAST) conducted its evaluation following the 1993 flood event. The GSS study used 2000 Census data to define housing and population changes within the floodplain and the 1993 flood extent. These analyses were conducted for the entire 1993 flood extent as defined by the SAST (considered the 1993 benchmark for future evaluations). This study conducted an analysis of the bluff-to-bluff area and floodwater inundated areas affected by the 1993 floods and identified commercial developments constructed in designated floodplains. This analysis was conducted using visual interpretation methods of Landsat satellite imagery. Landsat ETM+ data was acquired to analyze the most recent developments ("post-flood") and included cloud-free imagery from 2001-2003.
Photo Interpretation: * Photo Interpretation by professional photo interpreters * Floodplain extent evaluation and analysis of seven state area * Classification of land use/land cover data * Interpret satellite data of pre-flood and post-flood imagery using automatic and manual change detection * Analysis and trending of residential and commercial development using US census data Reporting Analysis: * Determine development since 1993 flood and eliminate risk areas deemed susceptible to next flood * Data interpretation and report generation * Resulted in recommendations from proven methods and data-evaluation Go back | Contact us for more information |
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