Remote Sensing of Flooding in the U.S. Upper Midwest during the Summer of 1993

Abstract

The U.S. upper Midwest was subjected to severe flooding during the summer of 1993. Heavy rainfall in the Mississippi River basin from April through July caused flooding of many Midwest rivers, including the Mississippi, Illinois, Missouri, and Kansas Rivers. The flood crest of 15.1 m at St. Louis, Missouri on 1 August 1993 was the highest ever measured, surpassing the previous record of 13.2 m set on 28 April 1973. Damage estimates include at least 47 flood-related deaths and a total damage cost of $12 billion. Remotely sensed imagery of severe flooding in the U.S. Midwest was obtained under cloud-free skies on 29 July 1993 by the MODIS (Moderate Resolution Imaging Spectroradiometer) Airborne Simulator (MAS). The MAS is newly developed scanning spectrometer with 50 spectral bands in the wavelength range 0.55?14.3 ?m. By combining spectral bands centered at 2.14, 0.94, and 0.66 ?m in red, green, and blue display channels, respectively, false color images were created from the MAS data obtained on 29 July 1993 that dramatically illustrate the extent of flooding near St. Louis and near Kansas City, Missouri. Estimation of the total flooded area in the MAS scene acquired near St. Louis was accomplished by comparing the MAS scene to a Landsat-5 thematic mapper (TM) scene of the same area acquired on 14 April 1984 in nonflood conditions. For comparison, the MAS band centered at 0.94 ?m and the TM band centered at 1.65 ?m were selected because of the high contrast seen in these bands between land and water-covered surfaces. An estimate of the area covered by water in the MAS and TM scene was obtained by developing land/water brightness thresholds from histograms of the MAS and TM digital image data. After applying the thresholds, the difference between the area covered by water in the MAS and TM scenes, and hence the flooded area in the MAS scene, was found to be about 396 km2 or about 153 square miles.