Maximum Depth of Sand
To determine the maximum depth of sand in any given profile requires:
 that each horizon in the profile be categorized by using the sand, silt and clay values
to place the horizon on the standard texture triangle; and
 that the profile be scanned from the surface downwards horizon by horizon for
membership in the 'sand' and 'loamy sand' categories. When a horizon is found not to fall
into one of these two categories, the upper depth of that horizon was taken as the
'maximum depth of sand' in that profile. If all horizons sampled fell into the two
categories, the value '999' was assigned and should be taken to mean that the maximum
depth of sand was unknown but exceeded the maximum depth sampled. In all cases, the units
associated with depth are centimeters.
The categorization of a horizon required:
 The development of an algorithm that
can project a point based on the composition percentages into the triangle
and, conversely, can convert a point in the triangle into an equivalent point
in a Cartesian coordinate system;
 The conversion of the vertices of the polygons in the triangle for all
soil types into such a coordinate system;
 The mapping of those coordinates into a graphic system such that
each soil type was uniquely colored; and
 The projection of a given horizon into that graphic system using the
composition percentages to determine the color of the pixel at that location
which, in turn, indicates the soil type.
If you wish to see the details of the process, click here.
