Lesson 9 How Do I Measure Height On A MapPresentation Transcript
Lesson 9: How do I measure height on a map? Aim: An ability to use contour lines and spot heights to interpret altitude on maps.
Do the odd one out activity with your partner (see worksheets).
Main Activity 1
Q1 Describe the relief shown in this picture.
Q2 How could you show it on a map?
Q3 Why would you want to show it on a map?
Create a short acted sequence to show what it would be like to walk over this terrain.
So how is height shown on maps?
Spot heights are those points that the OS has measured to be exactly that height (in metres) above sea level. They are marked on the map thus:
Always with a small dot marking the exact point.
This is what they look like on Ordnance Survey maps:
Now find an actual spot height on the OS map on your table.
Q4 What is its six figure grid reference?
Close together contour lines show a steep slope or gradient.
Q5 Find a slope on the map. What is its four figure grid reference?
Contour lines widely spaced show a gentle slope or gradient.
Q6 Find a gentle slope on the map. What is its 4 figure grid reference?
This set of contour lines represents a hill. The peak of the hill actually has a spot height of 386 marked upon it You can see that the contour lines form concentric 'circles' (complete loops of contour lines within another loop and so on). This is what defines the structure as a 'complete hill' rather than a slope or part of another feature.