Title: Basics of Mapping
1Basics of Mapping
- http//olc.spsd.sk.ca/DE/k9mod/Mapskill/mod3fl5.sw
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2What is Topography?
- Topography is the configuration of the land
surface, and it is shown on topographic maps with
contour lines.
Map of Valleys
Map of Hills
3- Topographic maps are useful because they
represent the three-dimensional image of the land
by using lines and symbols.
4- Topographic maps are useful tools for planning
highways, recreation areas, airports, housing
developments, etc. - For you, topographic maps may be useful for
recreational activities such as hiking, boating,
camping, fishing or hunting.
How could you use a topographic map when
camping?
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6What are contour lines?
- A contour line is an imaginary line on the
surface of the Earth connecting points of equal
elevation. - If you walk along a contour line you neither gain
or lose elevation. Â
7Contour Line Rules
- Each contour line represents one elevation.
- Contour lines never cross!
- The change in elevation from one contour line to
the next is the contour interval. - Typical contour intervals are 10, 20, 50, and 100
feet. - The contour interval is generally given in the
legend of the map.
8- Every fifth contour is printed darker.
- These lines are called index contours.
- On the map below, the 100 m contour line is the
index contour.
9What is the contour interval?
Which lines are index contours?
10List the elevation for A ___ B ___ C ___
D____
11A series of contour lines in a rough circle
represents a hill.
12- Closely spaced contour lines represent steep
slopes. - Widely spaced contour lines represent gentle
slopes.
13List the elevations for A ____ B ____
C ____ D ____ E ___
14Streams and rivers flow downhill (from higher
elevations to lower elevations).
Where a contour line crosses a stream or river
(or even a dry gully or valley), the contour
lines are bent sharply, forming a "V".
- The point of the "V" points uphill or upstream.
(Look at map and think about this for a minute.)
15- Closed depressions are indicated by contour lines
that form roughly a circle, with short "tick
marks" or "hachure marks" perpendicular to them
on the downhill side.
16Common Features