Agriculture Reference
In-Depth Information
answer of here or there requires one to elaborate more precisely, for
example: “I am the one with a blue baseball cap, standing on the south-
west corner of 35th Street and Broadway.” To limit any possible misunder-
standing, you could add, “in New York City.” Most people should be able to
locate you and pick you out of the crowd with such a descriptive answer.
The photograph in Figure 6.3 provides a vivid example of another
complexity in finding an appropriate answer to “Where is here?” The
concrete column in the center of the photograph was installed in a
field a couple of hundred years ago, along with several hundred similar
columns installed elsewhere throughout the Netherlands. The top of
the column is where the ground originally was when the column was
installed. The columns serve as witnesses to the extent of ground sub-
sidence at each location. The elevation difference, or extent of ground
subsidence in this instance, is just over six feet. This photograph serves
another purpose. It graphically demonstrates the ephemeral nature of
landscapes and of places. Ground subsides in some regions, and it shifts
laterally in others. It also is washed away or eroded in other locations.
Change, or even erasure, occurs across the landscape, sometimes very
slowly (such as ocean level rise), sometimes dramatically (e.g., slope fail-
ure caused by an earthquake).
Elevation
Control
Where
am I?
Horizontal
Control
Figure 6.2
Elevation and horizontal control
Figure 6.3
Elevation marker in a farm field near Delft, the
Netherlands. The distance from the ground to the top of
the marker indicates the extent of ground subsidence at
this location.
