standard os maps know the features of a standard os map. understand how relief is shown on an os...
TRANSCRIPT
Standard OS maps
Know the features of a standard OS map.
Understand how relief is shown on an OS map.
Be able to use four figure and six figure grid references.
By the end of this section, you will:
Standard OS maps
Ordnance survey
Ordnance Survey (OS) is Britain’s national mapping agency.
They produce most of the commonly used maps and map data for the British Isles.
What map features tell you what the land
is like?
What map features would help you
navigate?1km
N
Scale 1:50 000
Ordnance survey
OS maps contain:
1km
N
Scale 1:50 000
symbols and place names
contour lines and spot heights
a scale
grid references and grid lines
orientation
What do OS map symbols represent?
colour shading.
spot heights contour lines
How is relief shown on a map?
Relief is shown on maps in three main ways:
10-20 m
21-30 m
31-40 m
41-50 m
19
31
21
37
46
32
14
121020
3040
Contours are lines that join points of equal height.
Contours
Relief is often shown on OS maps by light brown/orange lines known as contour lines.
Contour lines usually have a number attached to them. This number indicates the height of the land above sea-level.
Labelling landscape features
Areas on maps can be identified with a grid reference. For example the highlighted square has the grid reference 0231.
The first two digit number is the easting. This is the
number at the top or bottom
of a map.
The second two digit
number is the northing.
This is the number at the side of a map.
Grid references
A grid reference is a set of two numbers, the easting and the northing.
00 0230
31
32
33
34
040301
Finding a grid reference
00 0230
31
32
33
34
040301
1. Find the easting by placing your finger on the 02 line at the bottom.
2. Find the northing by placing a second finger on the 31 line at the side.
3. Draw your fingers along the lines until they meet.
The square is North-east of the point where they meet.
How would you find the grid reference of square 0231?
Four figure grid references
What do the extra numbers mean in 024 315?
Sometimes we need to be specific about the location of a place.
Six figure grid references
Six figure grid references help us be more exact.
00 0230
31
32
33
34
040301
024 315 is the six figure grid reference of the church in grid square 02 31.
Finding a six figure grid reference
1. Use the first two digits of each three digit number to find the four figure reference, 024 315.
2. Imagine the square, 02 31, is divided into tenths vertically and horizontally.
3. Use the last digit of each three digit number, 024 315 to estimate lines at 4 tenths across the square and 5 tenths up the square.
4. 024 315 is the point where the imaginary lines cross.02 03
31
32
How would you find the grid reference 024 315?
4
5
Finding six figure grid references
Features of an OS map