Agriculture Reference
In-Depth Information
forms, building pads for the various structures, outdoor use areas, and
hardscape, including walks and roads.
Contour lines are created by land surveyors and compiled in a
topographic and land survey map. Land surveyors prepare topographic
maps either by a photometric process that uses aerial photography or on
the ground with crews using surveying instruments. In both cases the
information (data points) collected from the aerial photograph or sur-
vey instruments is analyzed, and through mathematical modeling the
points are converted to what we know as contours, lines representing
elevation. Converting the landscape into contours gives us a visualiza-
tion tool for making modifications such as for building roads or creating
level areas for building structures.
Contours not only help us understand elevation variation, they also
serve as an aide to visualizing natural landform and, in the built envi-
ronment, sloping planes and three-dimensional forms such as walls and
steps. The contours shown in Figure 7.2-B were drawn to help the viewer
visualize the relation between the two-dimensional construct of con-
tours and the forms they represent in the three-dimensional world.
What the LandScape WouLd LooK LiKe With
contourS
Figures 7.3 through 7.6 are further examples of what contours might look
like if they existed in the real, three-dimensional world. In these exam-
ples the contours help the viewer better understand the ups and downs
and the undulations of the ground surfaces. In Figure 7.3 the sculptural
form of the steps is exaggerated by the contours, while in Figure 7.4 the
sharply defined drainage swale of the rolling landscape becomes more
evident. The drainage swales in Figures 7.4 and 7.5 are enhanced by the
added contour lines, giving greater emphasis to the sculpted landform.
In both Figures 7.5-A and 7.5-B, the viewer can readily see the direction
of surface water flow toward a culvert. The water continues to flow in
the culvert under a drive via the drainage swale. The drainage swale
