Topographic Maps

Easting and northing

• Easting are vertical grid lines on a topographic map

• Northing are horizontal lines on a topographic map

4 figure grid reference

• Locates the grid square of a feature on the topographic map

• E.g. What is the 4 figure grid reference of the lower village in the following topographic map

Identify the grid square of the feature(Lower village)

Identify the easting and northing of the grid square of the feature(Easting-12, Northing-02)

The grid reference is the easting followed by the northing ; The 4 grid reference is 1202

6 figure grid reference• Locate the exact location of

a feature.• E.g. What is the 6 figure

grid reference of the lake at Cady Hill in the topographic map

Step 1:Identify the place of the feature

• Divide the grid square into 10 equal part

Using the divided grid square, identify the grid square of the feature

Identify the easting and the northing of the feature(Easting -3, Northing-4)

The 6-figure grid reference is the easting of the map followed by the divided line followed by the northing of the map followed by the northing of the divided line; The 6-figure grid reference is 123044

Finding direction using a compass on a map

• A compass have 4 points known as compass point, they are north, south, east and west

• E.g. What is the direction of the lake at the lower village from Cady Hill

Draw a north arrow on Cady hill

Draw a line from Cady Hill to the lake in the lower village

Look at the compass point, the line is pointing at Southeast; the direction of Cady Hill is southeast to the lake in the lower village

Finding direction on a map using compass bearing

• Compass bearing show the exact degree of the direction of a place

• E.g. What is the compass bearing of Cady Hill from the lake in the lower village in the topographic map

In order to find the compass bearing, we need a 360° protractor or a normal protractor(need more steps). First, draw a line connecting the features

Put the protractor’s centre point on the feature. Ensure that the 0 is facing upwards

The compass bearing is the angle where the line cut across the protractor; The compass bearing of Cady hill from the lake in the lower village is 133°

Measuring straight distance on a topographic map

E.g. What is the distance between the lakes in the lower village in the topographic map

To find the distance, we need a ruler and the scale of the map. First, take a ruler to measure the distance between the 2 features

The distance between the 2 lakes on the map is 1.7cm.To find the actual distance, we need to use the scale on the map. The scale is 1:100000 which mean 1cm on this map =100000cm(1km) in actual distance; The distance between the 2 lakes in the lower village is 1.7 X 100000=170000cm/1.7km

Measuring curved distance on a topographic map

E.g. What is the distance of the road from the lower village to Stowe in the topographic map

In order to find curve distance on a topographic map, you need a string. First, order the string on the curve distance

Take the string off and measure the distance by putting it straight and measuring the distance with a ruler

Multiply the scale with the distance to find the actual distance; The distance of the road from the lower village to Stowe is 10.8 X 100000= 1080000cm (10.8km)

Contours on topographic map

• Contours are imaginary lines that connect places of the same height above sea level

• It also show the relief of the place; If the contours are far apart, it means gentle slope and if it is near, it represent steep slope

Contour of a hillA hill is an area of highland, has gentle slope and a rounded peak. It is less than 600 meters high

A hill’s contour is in circular form increasing at the centre

Contour of a mountainA mountain is an area of highland, has steep slope and sharp peak. It is more than 600 meters high

A mountain’s contour is in circular form increasing at the centre

Contour of a valley

A valley is a low area in between highlandsA valley’s contour is pointing towards higher ground

Contour of a plateauA plateau is an up landed area which resemble a table top. It has steep slope

A plateau’s contour is closely spaced as it is steep and the top is broad

Contour of a ridgeA ridge is an up landed area that is narrow and steep sided

A ridge’s contour is closely spaced as it is steep and the top is narrow

Summary Easting and northing are vertical and horizontal grid lines on a topographic map respectively.4 and 6

figure grid reference show the grid square of a place and the exact location of a feature respectively. Identify the grid square of the feature first. Next, identify the easting and northing of the grid square of the feature. The 4 grid reference is the easting followed by the northing. Divide the grid square into 10 equal part. Using the divided grid square, identify the divided grid square of the feature from 1 to 10. The 6-figure grid reference is the eastings followed by the northings. A compass have 4 compass point. Draw a north arrow on the feature then look at the line pointing which is the direction. Compass bearing show the exact degree of the direction of a place. Connect the features with a line. Put the protractor’s centre point on the feature with 0° facing upwards. The compass bearing is the angle where the line cut across the protractor. A ruler and a string (for curved distance) is needed for finding distance. Order the string of the curve distance(For curved distance), next, measure the distance using a ruler, next, multiply the scale by the distance of the thing you are measuring on the map. Contours are imaginary lines connecting places of the same height above sea level and also show the relief of the place; Contours far away means gentle slope and contours near to each other means steep slope. A hill and a mountain is an area of highland. A hill less than 600 meters high, has a rounded peak and gentle slope while a hill is more than 600 meters high, has sharp peak and steep slope. A hill and mountain have contours in circles increasing at the centre. A valley is a low area in between highlands and has contours pointing towards higher ground. A plateau and a ridge is an up landed area with steep slope. A plateau has flat top while a ridge is narrow