MAP “PICTIONARY”
MAPS
Latitude
•
•
•
•
•
Lines run east – west
Main latitude line is the equator (0
degrees).
Lines are numbered 0 – 90 degrees,
north and south of the equator.
Both north and south poles are 90
degrees.
Memory hint: latitude sort of sounds
like ladder, so the latitude lines are
the rungs of the ladder.
Longitude
•
•
•
•
Lines run north – south
Main longitude line is the prime
meridian (0 degrees)(runs through
Great Britain).
Lines are numbered 0 – 180 degrees,
east and west of the prime meridian.
Memory hint: the longitude lines are
the long ones.
North arrow
•
•
Points in the direction of the
geographic north pole.
North may not always be at the top of
the map.
Magnetic declination
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•
•
•
•
A compass points in the direction of
the magnetic north pole (MN in the
north arrow above).
The magnetic declination is the angle
between the geographic north pole
and the magnetic north pole.
The magnetic north pole can either be
east or west of the geographic north
pole.
The magnetic declination is location
specific.
The magnetic declination changes
over time for all locations.
SCALES
Verbal
•
Is map specific.
“ 1 inch equals 1 mile”
Graphic
•
•
Units may be in feet, miles, meters or
kilometers.
Is map specific.
Fractional or Ratio
•
•
•
Example: 1 : 63,360 (1 = distance on
map; 63,360 = corresponding
distance in reality).
Unitless (can use anything, as in: 1
peanut on the map = 63,360 peanuts
in reality).
Is map specific.
1:63,360
or
1/63,360
Public Land Survey System
(PLSS)
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•
•
•
•
This system is used to legally
describe the location of properties
and can be found on the deed.
The PLSS location of the star in the
example to the right is T2S R2W
Section 13 NE ¼ SE ¼ SE ¼.
In Arizona the principle meridian and
the base line meet near the
confluence of the Salt & Gila rivers.
Baseline Road in the Phoenix area
runs along the base line.
On deeds, the PLSS location
description usually begins with the
smallest quarter section and ends
with the township& range designation.
Township
•
•
•
Measured north and south of the
base line.
The highlighted example to the right
shows Township 1 South (T1S).
Each township equals 6 miles.
Range
•
•
•
Measured eat and west of the
principle meridian.
The highlighted example to the right
shows Range 2 East (R2E).
Each range equals 6 miles.
Section
•
•
There are 36 sections to each
township & range area.
Each section is 1 mile wide.
The highlighted example to the right
shows Section 10 of T1S & R2E.
RANGE 2 EAST (R2E)
TOWNSHIP 1 SOUTH (T1S)
•
6
5
4
3
2
1
7
8
9
10
11
12
18
17
16
15
14
13
19
20
21
22
23
24
30
29
28
27
26
25
31
32
33
34
35
36
Quarters
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•
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Each section is divided into quarters
(i.e. NW, NE, SE, SW).
Then each one of these is further
divided into quarters.
Finally, these quarters are again
divided into smaller quarters.
The example at right would be (from
smallest quarter to largest quarter):
the SE quarter of the NE quarter of
the SW quarter.
NW
NE
NW
NE
SW
SE
NW
SE
SW
SE
TOPOGRAPHIC MAPS
Contour lines
•
•
•
•
Contour lines are lines of equal
elevation about sea level
They are usually colored brown.
Every 5th contour line is darker and
it’s elevation is usually displayed.
Contour lines never cross.
Hachure lines
•
Hachure lines are special contour
lines that represent depressions in
the land surface.
Contour interval
•
•
•
•
The contour interval is the difference
in elevation between two contour
lines.
The contour interval is map specific.
This can be calculated by using the
elevation shown for two contour lines
and dividing the difference in
elevation by the number of lines
inbetween them, or
Usually all topographic maps will
have the contour interval in the map
legend by the scales (see example)
Steepness
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•
•
•
The relative steepness of an area on
a topographic map can be determined
by looking at how close the contour
lines are.
The closer the lines are spaced
indicates a steep slope.
The farther apart the lines are spaced
indicates a gentle slope.
See examples to the right.
Gradient
•
•
•
The gradient is a measurement of the
steepness of an area.
It can be calculated by dividing the
difference in elevation between 2
points and dividing it by the horizontal
distance between the 2 points.
In the example to the right, the
gradient is:
100 ft = 200 feet/mile
0.5 miles
Streams and the Rule of V’s
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•
When contour lines meet a stream or
a wash, the contour lines form a “V”
which point upstream or up slope
The main stream in the center of the
map to the right flows from right to
left.
Hills
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•
•
•
Hills, mountains, etc. are represented
as a series of round contour lines.
For large mountains, the contour lines
still circle back but it may take several
maps to accomplish this.
The relative steepness of the hill
slopes can be determined by how
closely spaced the lines are.
The elevation for the top of the hill or
mountain is sometimes provided.
Cliffs
•
•
Cliff are represent by contour lines
that are extremely close together.
Sometimes it result in areas of just
brown color.
Buildings
•
Buildings are represented as squares
or rectangles.
High density areas
•
When the density of buildings is too
great, developed areas are shown in
light red.
Roads
•
Each different type of road is
represented by a specific type of line.
Railroads
•
•
Railroads are represent by a specific
line type.
Often the name of the railroad is
provided.
Vegetation
•
•
Vegetation is represented by green
coloration.
Sometimes agricultural areas such as
orchards will be a orderly green
pattern.
Water
•
Any water feature such as rivers,
streams, creeks, lakes, ponds,
canals, etc. are colored blue.
Swamps
•
Swamps, marshes, bogs etc. are
designated by the symbol pattern to
the right.
New updated features
•
•
•
Topographic quadrangles are
periodically updated.
Any new feature added since the last
map revision is shown in purple.
The date of the initial map and the
date of the revisions can be found in
the map legend at the bottom of the
quadrangle.
Surrounding topographic
maps (referred to as
quadrangles)
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•
The names of surrounding
quadrangles can either be found at
the center of each side of the map or
at each corner (see examples).
A graphic showing the surrounding
quadrangles may exist in the legend
at the bottom of the map (see
example).
Longitude numbers
•
•
•
•
Longitude coordinate numbers can be
found at each corner of the map (see
example).
The numbers are given in degrees (o),
minutes (‘) and seconds (“). The
example at the right is longitude 111o
45’.
Numbers that are greater than 90
degrees are always longitude
numbers.
Partial longitude numbers can also be
found at several locations along the
top and bottom of the map. The
example at the right is actually
longitude 111o 42’ 30”.
Latitude numbers
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•
•
•
Latitude coordinate numbers can be
found at each corner of the map (see
example).
The numbers are given in degrees (o),
minutes (‘) and seconds (“). The
example at the right is latitude 35o 22’
30”.
Latitude numbers are never greater
than 90 degrees.
Partial latitude numbers can also be
found at several locations along the
left and right of the map. The example
at the right is actually latitude 35o 17’
30”.
Township & range numbers
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•
•
•
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Township numbers can be found
along the left & right edges of the
quadrangle.
Range numbers can be found along
the top & bottom edges of the
quadrangle.
The numbers are in red.
On topographic maps there are
usually more than one township &
range on each quadrangle.
On the example to the right, there are
portions of 4 townships & ranges.
Since each specific township & range
has it’s own unique set of sections (1
– 36), each quadrangle there are
more than one section that has the
same number.
T3N
&
R6E
T3N & R7E
T2N
&
R6E
T2N & R7E
Section numbers
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•
Section numbers are red and are
centered within each section.
Remember, since each topographic
map contains portions of more than 1
Township & Range, there will be 2
sections with the same number.
Finding topographic maps
To find and download topographic maps:
http://store.usgs.gov/b2c_usgs/usgs/maplocator/(ctype=areaDetails&xcm=r3standardpitrex_prd
&carea=%24ROOT&layout=6_1_61_48&uiarea=2)/.do
Map symbols
For a complete list of topographic map symbols:
http://egsc.usgs.gov/isb/pubs/booklets/symbols/topomapsymbols.pdf
DIAGRAM
Contour interval
Contour lines
Depression
Latitude & longitude
Magnetic declination
North arrow
North arrow and magnetic
declination
Scale types
Steepness
Topographic map
Township & range
Township and range
CREDIT
http://raider.mountunion.edu/~mcnaugma/topographic%20maps/contour.htm
http://egsc.usgs.gov/isb/pubs/teachers-packets/mapshow/activity4.html
http://www.ramblers.ab.ca/public/outdoortopics/mapcompass.asp
http://www.nwic.edu/tenrm/spring2002/landgeol/lab1.htm
http://en.wikipedia.org/wiki/File:Magnetic_declination.svg
http://www.clker.com/clipart-north-arrow.html
http://www.google.com/imgres?hl=en&tbo=d&sig=105233084450650835823&biw=1280&bih=802&tbm=isch&tbnid=Rhnx
jfkaZOArbM:&imgrefurl=http://www.nwic.edu/tenrm/spring2002/landgeol/lab1.htm&docid=f81DHnOiSD4GTM&imgurl=htt
p://www.nwic.edu/tenrm/spring2002/landgeol/lab1_files/image006.jpg&w=94&h=196&ei=cp3DUKPiB6W30AHQlICAAQ&
zoom=1&iact=hc&vpx=212&vpy=505&dur=664&hovh=156&hovw=75&tx=61&ty=82&page=2&tbnh=154&tbnw=74&start=
33&ndsp=37&ved=1t:429,r:63,s:0,i:276
http://www.colorado.edu/geography/gcraft/notes/cartocom/elements.html
http://commons.wvc.edu/rdawes/G101OCL/Labs/TopoMapsLab.html
http://en.wikipedia.org/wiki/File:Topographic_map_example.png
http://www.rootsweb.ancestry.com/~mnwabash/survey.htm
http://geology.isu.edu/geostac/Field_Exercise/topomaps/plss.htm