geo Flashcards
How can we find distance on an Ordnance Survey map?
We can find distance in two ways: measuring a curved line like a road and measuring a straight-line distance between two locations.
Remember that 2 cm on the map equals 1 km on the ground.
How do you convert distance from cm to km on a map?
To convert distance from cm to km, divide the distance in cm by two.
How do you calculate the area of a regular shape on a map?
Count the total number of grid boxes or multiply the number of squares across by the number of squares down. Convert the answer to km².
How do you calculate the area of an irregular shape on a map?
Count the full boxes taken up by the area, then count any boxes that are half or more covered. Add these together and give the answer in km² approx.
How are slopes identified on Ordnance Survey maps?
Slopes are identified using contour lines, which are spaced 10 metres apart. The closer the lines, the steeper the slope.
What is an even slope?
An even slope has contour lines that are evenly spaced out.
What is a concave slope?
A concave slope has contour lines that are spaced out at the base and get closer together near the peak, indicating a gentle slope that becomes steep.
What is a convex slope?
A convex slope has contour lines that are closer together at the base and spread out near the peak, indicating a steep slope that becomes gentle.
What is a compound slope?
A compound slope has contour lines that are sometimes spaced out and sometimes close together, indicating varying steepness. It is also called a stepped slope.
Who uses Ordnance Survey maps and for what purpose?
County councils, developers, and other organisations use OS maps to decide where to build, such as residential areas, shopping centres, or factories.
What are vertical and oblique aerial photographs?
Vertical photographs are taken directly downwards, showing no horizon. Oblique photographs are taken at an angle, showing the horizon.
The bottom is called the foreground and the top is the background.
