Integrating Past, Present, and Future Approaches - Spatial Mathematics: Theory and Practice through Mapping - page 217

Figure 10.4 Grayson's interactive population potential map based on 2010 data.
Source of base map: Esri software.
London, has found a number of parallels to explore between the earlier work
of G. K. Zipf and spatial science (numerous works authored or co-authored
by Batty). In the present, Grayson's Potential Surface (2012) mirrors the ear-
lier hand-drawn maps of Warntz (1965), and of Stewarts's 1947 work (Figure
10.4). The underlying patterns are quite similar although Grayson's contem-
porary work is based on a finer mesh of pixels, uses color, and (most impor-
tant) is fully interactive. The user can see different views of the population
surface ( Figures 10.5 and 10.6 )!
When the scale of the Grayson map is made more local ( Figure 10.5 ) , it
becomes easier to see the parallels with Warntz's map. Zooming in, one
begins to see that what appears to be a continuous surface in Figure 10.4
actually appears to be made up of discrete units, each of which represents
1000 persons per kilometer (with warm colors representing higher population
potential). Enlarging the scale even more ( Figure 10.6 ) shows a dotted sur-
face quite similar to that of Warntz in concept although much more detailed
in terms of execution.
As Grayson offered a contemporary view of J. Q. Stewart's early work, we
offer readers an added opportunity to reflect on the work of Reilly, through
a trucking exercise, and the work of Zipf, through a touring exercise. The
thoughtful reader will no doubt look for ways to integrate these activities, lat-
erally in geographic space, through a systematic view of network analysis and
vertically, through a systematic view of map overlays and concepts involving
mapping already presented elsewhere in this work.
Another innovative approach to generate and visualize geographic data
is through Columbia University's Center for International Earth Science