Images of Iowa Landscapes
by James D. Giglierano
Satellite images taken from over 400 miles in space provide a
unique perspective on Iowa's landscape. Broad geologic features
can be seen underlying farm fields, forests, roads and towns.
Geological forces have modified these landscapes for thousands of
years, while human activity is a recent, but also significant
agent of change.
These views were taken by the Landsat 5 spacecraft and are
shown in "false color." Blue and green represent bare
soils with varying degrees of moisture. Pink and red indicate
healthy pastures and forests. Open water is black, while roads
and towns are white and magenta.
The Mississippi River flows through a narrow valley between
Davenport and Rock Island-Moline. Streaked deposits of wind-blown
sand and silt cross the landscape between the Mississippi and its
tributary, the Wapsipinicon River.
The wide Missouri River valley in Fremont County was
excavated by glacial meltwaters. Since then, the river has
meandered from side to side, leaving the scour marks evident
here. Today the river is confined to a narrow portion of its
floodplain by engineered levees, but the Flood of 93 again
covered much of the area between the bluffs.
This June 1991 image reveals the broad arc of the Algona
glacial moraine across Kossuth County. Remnants of countless
lakes and wetlands are seen as darker areas beneath the bare
soils of drained and plowed cropland.
Reprinted from Iowa Geology 1995, Iowa Department of