Replication of Results - Spatial Mathematics: Theory and Practice through Mapping - page 101

learned in this chapter, is the best color and symbol combination for the most
effective map interpretation? The underlying base map affects the interpreta-
tion of the map. Experiment with changing the base map and be sure to try a
light-gray canvas. What is the ideal base map to use for these data? It could be,
in your view, the light-gray canvas, or perhaps the lightly symbolized National
Geographic base map. Or, because you are examining the effect of altitude
and landforms on temperature, a satellite image base map, even though it is
not the simplest base map, might be the most effective.
4.10.2 Identifying and mapping trees for a stream bank erosion
control project
Color and mapping can also greatly enhance the understanding of local issues
and can aid in planning. Recently, Washtenaw County, Michigan has been
embarking on a major stream bank erosion control project. When that project
entered heavily forested residential lands adjacent to a creek, environmentally
sensitive residents quite naturally became concerned for the trees and wildlife
that would be destroyed or disturbed.
The County coded its easement with pink flags. It tagged selected large
trees or otherwise interesting vegetation with a blue band if they were to be
removed; it tagged trees within the easement with a red band if they were
to be left alone. All vegetation within the easement, except trees or shrubs
carrying red tags, was to be removed. Color was critical—a simple red/blue
confusion could cost a tree its life!
One neighborhood used Google Earth, together with a GPS-enabled smart-
phone, to make an inventory of trees present, along a half-mile stretch of the
creek, before the project began. David E. Arlinghaus did all the photogra-
phy with a smartphone that geotagged the images. He then transmitted the
images to S. Arlinghaus who did the mapping ( Figure 4.10 ) .
The accuracy of the geotagging of the photos was limited by several fac-
tors. First, the software in the smartphone has limits, as does the accuracy
of the GPS signals in heavily wooded areas, as we have seen earlier in this
book. Second, the geotagging of the photo is actually the geotagging of where
he stood to take the picture of the tree, rather than of the tree itself. He
attempted to stand at a consistent distance from trees to ensure accuracy (but
that is difficult in a densely wooded area). The level of precision, however,
was quite good—trees were in the correct position in relation to each other
and in relation to the dwelling units.
The geotagged camera images were downloaded directly to a computer by plug-
ging the smartphone into a new Windows 7 desktop computer. All 81 images
were stored in a single folder. That folder was then uploaded to the free software
called “GeoSetter.” From there, the geotagged images were batch uploaded to
Google Earth in a single operation (rather than entering each one individually).
The GeoSetter software was able to take the underlying geocoded coordinates