Environmental Engineering Reference
In-Depth Information
A common operation of a GIS is to combine specific digital data layers of similar geo-
graphic extent to produce new maps containing the input layers' spatial and descriptive
attributes. Figure 5.19 is an example of this layering process.
The use of multiple layers is recommended when constructing the base map using
geologic data of similar types of formation. For example, you can use a layer for glacial
deposits, fluvial deposits, lacustrine deposits, and marine deposits. Subdividing the input
of information into layers also assists with the editing process and may also be used to
develop multiple maps.
An example two-dimensional geologic map constructed using GIS of the Rouge River
watershed is shown in Figure 5.20 (Rogers 1997).
Figure 5.21 is the stratigraphic column for the Rouge watershed. Stratigraphic columns
list all geological formations depicted on a map in sequential order by age. Because
Qowd
Qow
Milford
Kettles
Kettles
Kames
Milford
Qmdo
Qmdi
Qme
Qmf
Qmt
Birmingham
Birmingham
Qmt
Qmk
Novi
Qma
Qow
Ice
Novi
Ice
Bergs
Qmf
Livonia
Livonia
Qma
Highest
Lake Maumee
~ 810MSL
Qmd
Detroit
Detroit
265
230
200
Ice
200
Mbd
Qmg
Ms
Mbd
Da
Ms
Da
Da
Dt
Dd
140
Qfa
Da
Dt
Dt
140
Dd
Qfa
Dt
Qmo
Qmo
Ddr
Dd
190
140
Dd
165
140
Ddr
(a)
(b)
Qmdi
Qowd
Qowd
Qmb
Qlalm
Qmdi
Qow
Qmf
Milford
Kettles
Qmt
Qmdo
Qowd
Kettles
Qmt
Qow
Qowd
Qmf
Milford
Kettles
Qmt
Qmdo
Kames
Qmk
Kettles
Qmt
Kames
Qmk
Qmdi
Birmingham
Qme
Qmbw
Qow
Birmingham
Qow
Qmbw
Qlsha
Ice
Qmf
Qmf
Novi
Qmdi
Novi
Lowest
Lake
Arkona
Ice
Bergs
Qlahm
Livonia
Lowest
Lake Maumee
Livonia
Qlsla
Qlahm
Qmd
Qmd
265
250
Detroit
200
Detroit
Mbd
Qmg
200
Ms
Mbd
Da
Dt
Dd
Qmg
Da
Ms
Qll
Da
Dt
Dd
140
Da
Qlc
Qfa
Dt
140
Qfa
Dt
Dd
Qmo
190
Dd
Qmo
190
140
Ddr
Ddr
140
(c)
(d)
FIGURE 5.15
(See color insert.)
(a) Rouge watershed, approximately 14,500 years before present. (b) Approximately 14,000
years before the present. (c) Approximately 13,750 years before the present. (d) Approximately 13,000 years
before the present.
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