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| gilgais   | R Documentation   |
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Line Transect of Soil in Gilgai Territory
-----------------------------------------

Description
~~~~~~~~~~~

This dataset was collected on a line transect survey in gilgai territory
in New South Wales, Australia. Gilgais are natural gentle depressions in
otherwise flat land, and sometimes seem to be regularly distributed. The
data collection was stimulated by the question: are these patterns
reflected in soil properties? At each of 365 sampling locations on a
linear grid of 4 meters spacing, samples were taken at depths 0-10 cm,
30-40 cm and 80-90 cm below the surface. pH, electrical conductivity and
chloride content were measured on a 1:5 soil:water extract from each
sample.

Usage
~~~~~

::

    gilgais

Format
~~~~~~

This data frame contains the following columns:

``pH00``
    pH at depth 0–10 cm.

``pH30``
    pH at depth 30–40 cm.

``pH80``
    pH at depth 80–90 cm.

``e00``
    electrical conductivity in mS/cm (0–10 cm).

``e30``
    electrical conductivity in mS/cm (30–40 cm).

``e80``
    electrical conductivity in mS/cm (80–90 cm).

``c00``
    chloride content in ppm (0–10 cm).

``c30``
    chloride content in ppm (30–40 cm).

``c80``
    chloride content in ppm (80–90 cm).

Source
~~~~~~

Webster, R. (1977) Spectral analysis of gilgai soil. *Australian Journal
of Soil Research* **15**, 191–204.

Laslett, G. M. (1989) Kriging and splines: An empirical comparison of
their predictive performance in some applications (with discussion).
*Journal of the American Statistical Association* **89**, 319–409

References
~~~~~~~~~~

Venables, W. N. and Ripley, B. D. (2002) *Modern Applied Statistics with
S.* Fourth edition. Springer.
