Satellite Image
of Iowa
by Mark A. Alexander and James D. Giglierano
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As seen from above, a view of
Iowa is very striking and changes dramatically with the seasons. In winter, snow
and low sun angle cause the shape of the land to stand out in stark relief. Spring
is heralded by the pale green of young grasses and the darkening of
row-crop soils from tillage. Our state becomes a deep-green sea of vegetation during
the summer and later changes into a patchwork quilt of autumn colors and
dry, crisp textures during fall harvest. Sixty percent of Iowa's surface area is
visibly altered each spring by farming activity. Springtime conditions across Iowa
are shown in this view from 438 miles above the Earth.
This color-infrared scene is a mosaic of 12 Landsat Thematic Mapper images taken between April and June, 1989 to 1993. Features on the ground have different colors due to spectral responses of materials to different wavelengths of light. Water appears black, while vegetation reflects in shades of orange to red. Note the drainage patterns across Iowa and the riparian vegetation zones along stream corridors such as the Wapsipinicon, Cedar, Iowa, Des Moines, and Little Sioux rivers. Bare soil varies between dark blue (wet) and light blue-green (dry). Wet streaks across northwest Iowa are caused by recent rain. Urban areas, such as Des Moines left of center, are purple. Other areas of interest are the forests and pastures of northeastern and south-central Iowa.