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Contours
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These slides will slowly tell you about contours wait until you see the NEXT button to move on.
Relief or shape of the land is shown by Contours
• Contours are those light brown or orange lines you can see on OS maps.
• A contour line is an imaginary line that joins points of equal height above sea level.
• The lines are numbered giving the height above sea level in metres.
• On an OS 1:50000 map the contours will be drawn for every 10 metre rise. Although on this map they are every 3m so always remember to check. NEXT
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What use are contours?
• They can be used to learn about the shape of the land (the relief).
• A map with only a few contour lines will be flat (and often low lying)
• If a map has lots of contours it is a mountainous or hilly area.
• The actual pattern of the lines will tell you more detail about the area too.
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• It is important to remember that the closer together the contour lines the steeper the slope.
•Let’s have a look at why that is.
Steep slopes
Area that is flatter with only a gentle slope
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• This is the side view of a hill.
Sea level
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Let’s see where this hill reaches these heights
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Now let’s plot those points
See how these lines are closer together on the steeper slope NEXT
Now if we plotted those points on paper.
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Let’s look at some other examples
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Think where is the steepest slope on this island?
Click here to see if you’re right
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Sometimes spot heights can be shown as a dot with a note of the height of that particular place.
A trigonometrical point (or trig point) shows the highest point in an area (in meters) and is shown as a blue triangle
Steepest slope – contour lines are closest together
Sparrow point 227
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You can spot other features by the shape and pattern of the contours
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A valley may look like this…
Often with a river running down through the valley
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However a spur can look very similar !
But here the heights are increasing in the opposite direction – always double check which way the contours are increasing or decreasing.
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Valley Spur
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Now Try your hand at a short test or click on the return button to re-run this
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