1
F.3 Map Reading
1.
Scale
a. Statement Scale e.g. 1 cm to 50 m
b. Representative Fraction e.g. 1: 5000
c. Linear scale e.g.
Fill in the following table to change the scales
Statement Scale
Representative Fraction
1 cm to 2 km
1: 200000
1cm to 40 m
1: 4000
1cm to 10 km
1: 100000
1cm to 200m
1: 20000
Linear scale
0
10
2. Distance
Distance = distance on map x scale
What is the distance from A to B in meters?
a.
A
6.4 × 500m
= 3200 m
B
1: 50000
b.
A
8 ×20 m
B
1cm to 20 m
=160 m
20 km
2
3.
Grid References : Grid square and 6-figure grid reference
03
●D
02
●C
●A
●B
41
42
43
1.
The northing numbers are 01, 02, 03
2.
3.
The easting numbers are 41, 42, 43, 44
What are the 6 figure grid references of
A _____411019________________________
B ______422015_______________________
C ______434025_______________________
D ______424025_______________________
The grid square where you can find B is ______4201_____________
The grid square where you can find D is _______4202____________
4.
5.
44
3
4.
Direction
a. Compass points
b. Reduced bearing
Measure from the north or from the south.
N
A
C
D
B
A: N67°W
S
B: S62°W
C: N50°E
D: S63°E
c. Whole circle bearing
Measure from the north in clockwise direction.
N
A
303°
4
5.
Map symbols
5
Symbols for 1: 20 000 map
6
7
Exercise 1
Marks: _______________
1:20000
a. Number the grid lines
b. Shun Lee Estate is mainly located in the grid square ____1472____________.
c. What can we find in the grid squares 1372 and 1472? __D___________
(1) Public housing estate
(2) Steep slopes
(3) Temple
(4) Fire station
A. (1) and (3) only
B. (2) and (4) only
C. (2), (3) and (4) only
D. (1), (2) and (4) only
d. Change the map scale into statement scale __1cm to 200 m___
e. What is grid reference of spot height 584 (Middle Hill)? 139738
f. What is the grid reference of trigonometrical station 602? 140731
8
Exercise 2
a.
b.
c.
d.
Marks: _____________
Change the scale on the map to statement scale and linear scale. 1 mark
What is the actual distance between the entrance and the lookout in metres? 1 mark
6.2 X 500 m = 3100 m
What are the grid reference of the following objects?
i.
the entrance of the trail: 216099
ii.
the information board:214101
iii.
the lookout215(6)105
Find the following directions
i.
the compass point of the lookout from the entrance NNW
ii.
the whole circle bearing of the entrance from the lookout ___170°__________
iii.
the reduced bearing of the information board from the spot height 83 __S40W__
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6.
Area
a. Regular Area
Y
X
Scale: 1: 2000
What is the actual area of the block bove?
Actual length of X =
3.2×20=64m
Actual length of Y = 5×20=100m
Actual area of the block
= 64m×100m
=
b.
6400m ㎡
Irregular Area
Refer to figure 1.2. What is the actual area
Of the island in km²?
Scale = 1: 20000
(21×0.5＋9)×0.04km²
=0.78km²
10
7.
Cross Section
1: 20 000
8.
Vertical Exaggeration
= vertical scale
horizontal scale
Refer to Figure 1.17(b).
1
8000
1
20000
=1
8000
X
= 2.5 times
20000
What is the vertical exaggeration of the cross section?
11
9.
Intervisibility
Which points are intervisible? ____XY_____
_____YZ__________
Which two points are not intervisibile?
_______XZ___________
10. Gradient
= vertical difference in height
horizontal distance
a.
What is the gradient of the slope A B?
b.
50 100 150
What is the gradient of slope XY?
200-50
3×200
x
Y
River
1:20000
200
=150
600
= 1 in 4
What is the gradient of the river?
200-0
3.5×200
=1 in 3.5
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Exercise 3
1.
b.
c.
d.
e.
Refer to the map on the next page
ai Express the scale of the map (2 marks)
in a statement scale 1cm to 250m
in a representative fraction 1:25 000
What is the distance from Farm A to B (2 marks)
in a straight line about 2.6 km
by road (the shortest route) about 3.7km
What is the area of each square on the map in metres? 250 000m2 (2 marks)
What is the approximate area of
i.
Farm D?_0.625 km2 (2 marks)
ii.
Farm A?_1.5km2 (2 marks)
What is the direction of the church in Lowerham (602266) from Farm B (661304)?
i.
in compass points _SW (2 marks)
ii.
in whole circle bearing?240 (2 marks)
f. No
g. Draw a cross section from X to Y. On the cross section mark the following. (10 marks)
Two hills
river
woodland
farm
main road
Title: A cross section from X to Y
h. What is the vertical exaggeration of the cross section?
Vertical scale
Horizontal scale
___1__
10000
1
25000
= 2.5 times
13
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11. Relief features
A.
Methods of showing relief and height on topographical maps
1. Contours A contour line is a line joining places of equal height on a map.
2. Layer colouring – lower ground: green
Upper ground: brown
3. Fathom lines – Fathom lines are lines on maps joining places of equal depth below sea
level.
One fathom is equal to 1.83 m
4.
Trigonometrical stations e.g.
5.
Spot height
15
B.
Relief features
16
9
17
18
19
Exercise 4
Name the above features with the choices below.
Steep slope
knoll
ridge
even slope
Gentle slope
valley
spur
i.
steep slope
ii.
gentle slope
iii.
concave slope
iv.
v.
vi.
even slope
ridge
knoll
concave slope
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Exercise 5
150
150
100
50
a. conical hill
g. spur
b. gap
c. convex slope
h. ridge i. gentle slope
d. concave slope e. steep slope
j. round-topped hill
f. valley