Aim: Topographic Maps
Do Now:
Take an Understanding
Altitude Worksheet and begin
answering the questions based
on the diagram on the back of
the worksheet.
I. Topography Vocabulary
a) Altitude:
elevation above sea
level or any other
point on earth's
surface.
b) Field Map:
A map on which measurements
are plotted and connected
using isolines
“iso” means equal
1000 meter isoline
900 meter isoline
Key:
units in meters
c) Relief map:
Uses a 3D image to show elevation.
- Colors could be used to show difference in
elevation.
II. Contour Maps
a) Topography:
The shape of the land on Earth’s
surface (mountains and valleys)
Chimborazo, Ecuador
K2, Pakistan
b) Topographic Maps:
-show the shape of earth’s surface using
isolines.
- on a topographic, isolines are called
contour lines
- Contour lines show
points of equal
elevation
c) Index Contour Lines:
Heavy lines spaced at a predetermined
elevations on a topographic map.
Index contour line
d) Contour Interval:
The vertical distance (up the hill
or down the hill) that separates
each contour line on a
topographic map.
e) Hachure marks:
refer to a drop in elevation.
Indicates a depression in the
ground.
Copy diagram into notes, we will
look at this when Mr. Greenberg
returns
f) Bench mark: shows the exact
elevation at that point.
g) Closer contour lines =
steep slopes on the land.
h) Further contour lines
= gradual slopes on the
land.
i) When a river or stream crosses a contour
line, the contour line bends and points
upstream. This is where the river is coming
from.
Copy diagram into notes
j) The highest possible point on a contour
map will always be one unit less than the next
possible contour line.
Copy diagram into notes, we will
look at this when Mr. Greenberg
returns
X
Contour Interval = 10 m
10 m
Closure
Obtain the worksheet called “Reading a
Topographic Map” from the back table
and complete the worksheet. We will go
over it when finished.
Aim: What is Gradient?
Do Now:
1) Tell me the contour interval
of this map.
10m
2) What is the highest possible
point at the bench mark?
99m
X
Contour Interval = ___
X = bench mark
90m
70 m
Gradient (slope)
-The change in field value over the
distance that change took place.
- For topographic maps, you look at
your vertical distance over your
horizontal distance.
Change in field value
Gradient = __________________
Distance
**The formula is on the over
of your ESRT
Gradient examples -A hiker climbs 250 meters up a
mountain from it’s base to the peak
(vertical). The peak, is 3 km from the
base (horizontal). What is the gradient
of the mountain side?
Copy example into your notes
Peak
250 m
Base
3 km
Gradient examples -
Change in field value = 250 meters
Distance = 3 kilometers
Gradient =
250 meters
3 kilometers
Gradient = 83.3 m/km
•You and your lab partner should
each obtain a piece of white paper
•Wait for more instructions
Name
Date
Play Dough Mountain
• Your mountains should
have a base that is larger
than its peak.
• Your mountains should
not have very steep
slopes.
Build Mountain Here
• Your mountains should
not have a skinny or
narrow peak.
• Your mountains should
not have any other
features on them.
AIM:
How do we draw contour lines?
DO NOW
• Take the Gradient packet from the back and
answer question 1and 2 only.
Isolines:
10 0
Iso = similar or the same
Connect points of equal
value on a field map.
10 0
Examples
10 0
Isobars, Isotherms, Contour lines
10
0
10 0
Rules for Drawing Contour Lines
1. Contour lines don’t cross each other
-
Although at a vertical cliff they may be on top of one
another
2. Contour lines should close on themselves
-
Even if this takes place off the map
3. Contour lines become more closely spaced
when the gradient increases
4. Contour lines become further apart when the
gradient decreases
Rules for Drawing Contour Lines
5. Closed contours appearing on a map as an
ellipses or circles represent hills.
6. Closed contours with hachure marks
represent depressions
7. Where contour lines cross streams and rivers
they have a v-shape and the v points
upstream.
Do Now: REMOVE EVERYTHING
FROM THE DESK AND THE AISLES
• Take a Constructing a Contour Map
Lab and one piece of transparency film
for you and your partner from the front
table
• Take a plastic box with model volcano
and a plastic bottle or container from
the back for you and your partner.
• Begin defining the 5 vocabulary terms
on the cover page of the lab.
We have ONE period to complete this
portion of the lab and you must be
quiet so we can start. There is a lot
going on for this lab and you must
pay attention. We need at least 25 min
to complete this portion and we must
watch a video on how to do this.
Watch the Video for instructions on how to do the lab
AIM: How do we make profiles?
Do now:
1) Obtain Both worksheet from the side of the room.
2) Get a ruler for you and your partner to share
I. Contour Profile
- The shape you would see if the
land were sliced vertically along a
line between two points on a
topographic map (side view)
II. Steps for Drawing Topographic
Profiles
1. Get a
piece of
scrap paper
2. We will be making a profile
between points B and C. Draw a
straight line between these two
points
B
C
3. The other side of your sheet has the
graph we will sue to plot the profile.
Label this graph using the Contour
interval
140
120
100
80
60
40
20
0
4. Place your scrap paper across the line
we drew on the map. Every place a
contour line crosses our scrap paper
place a mark and label the mark with
the elevation of that line
B
C
5. Take your scrap paper and move it to
the graph on the back of the page.
Transfer the tick marks we made on the
scrap to the graph
140
120
100
80
60
40
20
0
Gradient for line AC
Copy formula from ESRT Change in field value - 30 m
Distance – 30 km
Gradient =
30 m
30 km
Gradient = 1 m/km