The major flood on the Mississippi River in 1973 initiated a broad program of studies to delineate morphologic and geologic changes in the river. A summary of the changes in the morphology of the river and an inventory of the surficial soils in the river valley was made in 1975. The surficial soils reconnaissance maps were interpreted from high-altitude (1:125,000) color infrared photography. The mapping methodology consisted of selective imagery characteristics interpreted with a Bausch and Lomb Zoom Transfer Scope and transferred to a 1:62,500 USGS 15-minute topographic map. The morphological changes were delineated using panchromatic aerial photography at scales varying from 1:10,000 to 1:62,500. The time periods selected for change detection were the 1930's, 1940's, 1960's, 1973 (prior to 1973 flood), and 1974 (post flood). The delineations outlined the river channel, vegetated bars, sand bars, chutes, dikes, and islands. The tracings were all reduced to a scale ratio of 1:62,500. Examples of the map products and a summary of applications are described.
The cost of various mapping methodologies is presented and optimum mapping procedures are proposed. The future applications and uses of the proposed mapping techniques are outlined.