Strand 2: Map Projection and Scale issues

Question 1

What is Georeferencing?

Answer 1

• Involves assigning a spatial location to an item of information
• Process of taking a map layer, assigning it a projection and coordinates, and translating it into a position relative to some other spatial data.

Question 2

What are the 3 characteristics of Georeferencing?

Answer 2

Should be:

1. Unique
2. Shared
3. Persistent through time

Question 3

What are the single most comprehensive and power methods of Georeferencing?

Answer 3

LONGITUDE & LATITUDE

Question 4

What are the benefits of Longitude and Latitude?

Answer 4

• Proved potential for very fine spatial resolution
• Allows distance to be computed between pairs of locations
• Supports other forms of spatial analysis
• Used universally

Question 5

Define Latitude

Answer 5

The angular distance in degrees, minutes and seconds of a point north or south of the Equator. Lines of latitude are often referred to as parallels

Question 6

Define Longitude

Answer 6

The angular distance in degrees, minutes and seconds of a point East or West of the Prime (Greenwich) Meridian. Lines of Longitude are often referred to as meridians.

Question 7

What shape is the Earth more accurately modeled as?

Answer 7

Spherical (ellipsoid)

Question 8

The Earth is slightly flattened such that the distance between 2 poles is about…

Answer 8

1 part in 300 less than the diameter at the equator

Question 9

What 4 things change when distortion of the world takes place? (ORANGE PEEL)

Answer 9

1. Shape
2. Direction
3. Distance
4. Area
   DADS

Question 10

What are the types of Map Projections?

Answer 10

• The Lambert Conformal Conic
• The Mollweide
• The Orthographic Projection
• The Azimuthal Equidistant
• The Winkel Tripel
• Mecator Projection

Question 11

Define Scaling

Answer 11

The process of reduction involved in moving from reality to map

Question 12

What are the 3 ways to express a scale on a map?

Answer 12

1. Representative Fraction
2. Verbal
3. Graphic Bar

Question 13

Is the level of detail more or less if the Map Scale is Large and the Mapped Earth is Small?

Answer 13

MORE

Question 14

Is the level of detail more or less if the Map Scale is Small and the Mapped Earth is Large?

Answer 14

LESS

Question 15

When it comes to MAUP, define the Scale problem.

Answer 15

Variation in results obtained when data for one set of areal units is replaced with another

Question 16

When it comes to MAUP, define the Zone (or aggregation) problem.

Answer 16

Variation in results obtained from different ways of subdividing geographical space at the same scale

Question 17

Why is okay for Britain to use the British National Grid Co-ordinate System once it has been ‘scaled’?

Answer 17

Because Britain is relatively small and therefore distortions are minimal and thus co-ordinates fairly accurate
Not necessarily true for larger countries!