Other Dimensions, Other Tools, Other Solutions - Introducing Geographic Information Systems with ArcGIS - page 537

CHAPTER 9 OVERVIEW

IN WHICH we examine the third
spatial dimension in GIS; time and
GIS; address geocoding; network
analysis; and linear referencing.

Other Dimensions,
Other Tools, Other
Solutions

Two Different Third Dimensions: The
Temporal and the Vertical Spatial

So far in our GIS work, although it pains me to say it, we
have had all of the disadvantages and none of the advantages
of the fact that the world (and everything in it) resides in
four dimensions. The disadvantages have come about partly
because (1) the Earth is approximately spherical—requiring
all that projection complication in moving from three spatial
dimensions to zero, one, or two dimensions—(2) three-
dimensional stuff is just harder to deal with, so we have
contented ourselves with “flatland” in which nothing is quite
right, and (3) it's hard enough just to get a dataset right at a
given moment or period in time—never mind historical or
anticipatory data sets.

But now we take on, separately, the third spatial dimension
and the time dimension.

I present the Overview and the Step-by-Step sections together
for each topic. When we say 3-D GIS, we usually mean three
spatial dimensions. The title of the next section is meant to
convey that idea. However, in the section after that, which
is “3-D: 2-D (Spatial) Plus 1-D (Temporal),” we will take up
looking at what happens to two-dimensional data over time.