How to Make a Topographic Profile

1
How to Make a Topographic Profile
300
400
200
100
This represents a very simple topographic map of
a hill. The hill is steep on the left side (the
contour lines are very close together) and has a
gentle slope on the right side. The numbers
represent the elevation of the contour lines. ()
What would the hill look like if you were to
slice it from left to right? ()
2
How to Make a Topographic Profile
300
400
200
100
Again, think of the cardboard analogy. Every
layer of cardboard would represent 100 feet of
elevation (the same as a contour line). You
would have 4 layers of cardboard. Viewed from
the side it would look like this ()
Thus, you have a somewhat blocky profile of what
the hill looks like. ()
Each layer of the hill has a different piece of
cardboard. To determine the size, draw lines
from the hill down to the appropriate layer of
cardboard. ()
3
How to Make a Topographic Profile
300
400
200
100
Thus you have a topographic profile. This is
what the hill would look like if you were to cut
it along the profile line and look at it from the
side. ()
Normally, the Earths surface is not this blocky.
In a topographic profile a line is drawn from
these points (red dots) producing a smooth
transition. ()
4
Now its your turn. ()
This is the profile line from A to B. Where
this black line crosses the INDEX CONTOURS (you
do not have to do every contour line) draw a line
down to the appropriate contour elevation
(layers) below. ()
5
The contour interval of this map is 40 feet.
Every index contour would then be 200 feet.
8000
7800
7600
7400
7200
7000
6800
6600
6400
Find this page in your Topo Worksheet Packet
6
The contour interval of this map is 40 feet.
Every index contour would then be 200 feet.
8000
7800
7600
In this region the profile line cut across the
7800 foot line 4 times. ()
7400
7200
7000
6800
6600
6400
The profile is finished. ()
The last step is to simply connect the dots.
()
7
This is a very classic example of a butte with
steep sides and a very flat top. The profile
that you see here is an exaggerated scale the
vertical scale is greater than the horizontal
scale. The next example is where the vertical
scale is closer to the horizontal scale. ()
8
In this example the butte is still the same
horizontal distance, but the vertical scale has
been compressed. If the vertical scale was
bigger it would produce more exaggeration. ()
These are just different representations of the
same butte. On the test, the profile that you
will be asked to draw will be simpler than this
one. ()
9
THE GRAND CANYON, ARIZONA
This view of the Grand Canyon is from the South
Rim looking north into Bright Angel Canyon. This
is what it looks like on a topographic map. ()
10
THE GRAND CANYON, ARIZONA
It may not be as majestic but it is full of
information. ()
This view of the Grand Canyon is from the South
Rim looking north into Bright Angel Canyon. This
is what it looks like on a topographic map. ()
11
Cumberland, Pennsylvania/Maryland
Based on the slope information provided by the
brown contour lines, the tributaries flow down
fairly steep slopes (the contour lines are close
together) making them YOUTHFUL streams. The main
stream occupies a valley that has very few
contour lines. In fact the wide spacing of these
contour lines represents a floodplain placing
this river in the MATURE stage. ()
Try to visualize what this profile would look
like before you move on. ()
Just for fun, lets construct a topographic
profile across the main stream from point A to
point B. ()
12
Cumberland, Pennsylvania/Maryland
Using every INDEX CONTOUR 100 foot interval
()
Print this page if you want to draw the profile.
The next slide goes through the process. READY ?
()
13
Cumberland, Pennsylvania/Maryland
Using every INDEX CONTOUR 100 foot interval
()
Stream
Now just connect the dots and draw a smooth
profile. The stream occupies the lowest point of
the valley. ()