Spectral Unmixing Applied to Desert Soils for the - Naval ...

Figure 9. The above figure is a map of world soil types and their distribution adapted
from the http://www.cals.uidaho.edu/soilorders/i/worldorders.jpg (2012).
Notice that the primary soil types associated with the arid regions in Figure
7 are Aridisols (orange), and Entisols (pink) to some extent.
B. CHEMICAL AND BIOLOGICAL SOIL COMPONENTS
1. Soils
Aridisols are the predominant soil type associated with the desert environment
(Whitford, 2002). Figure 9 illustrates different soils throughout the world along with their
respective regions, and Figure 10 shows the percentage distribution of aridosols in the
United States. Aridosols are CaCO3 containing soils generally found in arid regions that
experience some subsurface horizon development. Characteristically, these soils are dry
through most of the year with limited leaching (Balba, 1995; Whitford, 2002).
Subsurface horizons have accumulations of clays, calcium carbonate, silica salts,
and gypsum in some cases, though gypsum and calcium carbonate tend to leach from
soils in most climate types (Balba, 1995). The properties of the subsurface soil horizons
are important to know because variability in soil materials is detectable through Imaging
Spectrometry (Clark, 1999; Kruse et al., 2000) and their presence may
tell something about activities in the area (Webb et al., 2009). Other soil types also found
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