Transcript How to Draw Map Profiles

From RegentsEarth.com
This topographic map
shows a region of space
(a field) as it would appear
if you were directly above it.
Your job is to convert this
‘above’ view into a sideways view, a profile of the
region from point A to
point B.
You will need a pencil and
a ruler (or other straight
edge).
First: draw a line from
point A to point B.
At every point where line
A-B crosses a contour line
you will have to draw a line
straight down to the
corresponding line on the
grid below.
Since you’re just starting out
it may be helpful to make a
small mark at each point
where you will draw a line.
This may prevent you from
missing points.
By counting these marks,
there are 16 of them, you
will know that you must draw
16 lines. Later you can check
yourself to be sure you have
drawn them all.
The first mark you made was
at point A. Notice that point A
is on the 200m contour line.
You must now draw a
vertical line from point A to
the 200m line on the grid
below.
The next mark is on the
300m contour line. Draw a
vertical line from that mark
to the 300m line on the grid
below.
Now continue to draw
straight, vertical lines from
each mark to the
appropriate line on the
grid below.
Using a pencil, connect the
bottoms of the lines. Try to
connect them with one
smooth, curving line rather
than a series of short,
straight ones.
Please notice that here
the line went above 500m
but well below 600m.
That’s because this area
of the map is above 500m
but less than 600m. We
know this because there is
no 600m contour line here.
The same principle applies
here.
Your line must go below
the 300m line and above
the 200m line.
That’s because if you were
standing here you would be
between the 200m and the
300m contour lines.
And again, if you were here
your altitude would be more
than 600m but less than
800m (there is no 800m
contour line on this map).
Therefore you must be
careful to make your line
here go above 600m and
below 800m.
Make it OBVIOUS! Make
your lines go in the middle
between the grid lines so
anyone scoring your profile
will understand.
OK. Final check.
You were supposed to draw
16 lines. Did you?
Are the lines you drew
straight, parallel and
vertical?
Are all the lines drawn to
the proper grid line?
Do your peaks and valleys
go obviously between
grid lines?
Why bother checking?
Because most students
lose points not because
they don’t know how to do
this.................
but because they’re
SLOPPY!
Good enough ISN’T
good enough!
A slightly different situation:
Here we have another
contour map. Your job
is to construct a
profile along a straight
line from points A to B.
The problem is that
the grid on which
the profile is to be
constructed is in
the answer booklet
on a completely
different page.
To make matters
worse, the line A-B
on this map is on a
slant.
What to do?
STEP ONE
520
530
530 520 510
510
520
540
530
Using the contour
interval below the
map, carefully label
each contour line
crossed by line A-B
with its elevation.
Make sure you don’t
label this line........
It’s not a contour line.
It’s Colden Creek.
So we can check
ourselves later,
count how many lines
are labeled starting
with the 550 line at
point B.
You should have
counted 10 lines.
When we’re finished
we can check to be
sure we’ve drawn
them all.
STEP TWO
520
530
530 520 510
510
520
540
530
A
550
B
Place a blank piece of
paper (here shaded
blue) over the map
just under line A-B.
Make a small mark on
the paper by each
contour line.
Now label each mark
with the value of the
contour line it
represents.
and label A and B
so you’ll know which
end is which.
Reminder: The number
533 is the maximum
elevation of Aurora
Hill and the triangle
marks that spot. It is
NOT a contour line
and should be ignored.
STEP THREE
This is the grid as it appears
in the answer booklet
provided with the regents.
You are to construct your
profile on this grid.
Take the paper you marked
with the contour line values
and line it up below the
grid so that the ‘A’ mark on
the paper is below ‘A’ on the
grid and the ‘B’ mark on the
paper is below ‘B’ on the
grid.
Now, just as you did in the
first example, take a straight
edge and carefully make an
X on the grid corresponding to each value on the
paper below. The X for points
A and B have been made for
you.
STEP THREE
Many students prefer to draw
the lines but you do not have
to. You can just put in the X’s
Now connect the X’s using
a single, smooth, curving
line.
x
x
x
x
x
x
x
x
Be sure your ‘peaks’ and
‘valleys’ go above and below
grid lines just as in the first
example.
One last check. You were
supposed to have marked
10 points on this grid. Are
they all there?
YES! Counting the points
marked for you (A and B)
there are 10 X’s.
WELL
DONE