Map Skills Flashcards
What do maps show
They show the view of the land from directly above
What do vertical aerial photographs show
A view of the land from directly above the ground
What is a orthophoto map
A map of an area that is created using an aerial photograph, it has been geometrically corrected and has a uniform scale
Define contour lines
Symbolic horizontal lines which indicate the height and shape of a slope
Define landscape features
Physical features we can identify on the land
How do we represent objects on the ground in a map
Using symbols and colours
How do contour lines work
Each contour line connects places that are the same height above sea level.
Why do we use contour lines
To provide information about the height and shape of landscape features
Who decides how many contour lines to show on a map
Map makers
What is a contour interval
The distance between each contour
Define cartographer
A person who makes maps
How do cartographers get info about the land
Vertical aerial photographs
Satellite images
Land surveys done by peoe on the ground
Define gradient
The angle of a slope compared to the horizontal. The steepness of a slope
How do we identify a gentle gradient
If there is a big difference in the height between two places is small and the land distance is long
What do we need to calculate gradient
We need to know the height difference between two places and the horizontal distance between the two places
Read through pg 7
What do vertical aerial photographs show
Views of the land taken from a camera fixed under a special aeroplane. They show the land directly above earth’s surface
What do oblique aerial photographs show
The Lans from above but also from an angle
Which map is more useful to cartographers and why
Vertical aerial photographs because they show earth’s surface from the same angle as a map
Describe the scale of a vertical aerial photograph
Is it only accurate close to the centre of the photograph
Define orthophoto image
A picture of the land that is made using computer technology
Define distortions
Not the true shape of objects
Define orthophoto map
A rectified image based on an aerial photograph with additional information from a map
Define grid
A set of regularly spaced lines which provide a mathematical base for a drawing
How are orthophoto images made
Using information from vertical aerial photographs
What do orthophoto maps display
Place names Contour lines Heights Road numbers A grid showing coordinates
Define spot height
Points marked with a dot that show the exact height of the land
What are the contour intervals of orthophoto maps
5 metre intervals
What do contour lines on an orthophoto map indicate
the shape and the height of different features
Define topographic
Shape of the land
Define natural features
Parts that are naturally occurring
Define constructed
Made by people
What is the scale of a tographical map
1: 50 000
What are topographic maps
A map that indicates the features of the land’s surface, such as mountains, valleys and hill, using contour lines.
What does colour help with on a map
Makes it easier to identify the meaning of the symbols in the key
Read through symbols on pg 12
Define perennial river
Flows throughout the year
Read through pg 13
Define trigonometric beacon
A triangular symbol showing the exact height of a place and its own number
Define benchmark
A map symbol with an arrow, showing the exact height of a place, in decimal numbers
What do darker contour lines mean
They show the height 100 metres apart
The numbers on the contour lines help you to see if a slopeis sloping up or down. They always face up the slope
What is spot height
Shows the exact height of a place in metres, as a number next to a dot
Read through pg 16-17
Define ratio
Compares one number to another number of the same unit
Define line scale
A line which marks the distance on a map compared to distance on the ground
Define alpha-numeric grid
A grip with letters and numbers
