1. Map Projections & Types of maps
AP Human Geography

2. Map projections

3. Map projections
Cartographers have to deal with the problem of making maps of a spherical earth onto a flat surface  this leads to distortions
Shape can be distorted
Distance between two points can increase or decrease
Relative size may be altered, areas can appear much larger than they really are
Direction can be distorted

4. Robinson projection

5. Robinson projection More accurately shows the area near the poles
Used to show proportions of land to water
Distorts cardinal directions and distance

6. Mercator projection
Used primarily for navigation since it is easiest to plot direction
Increased distortion the further away from the equator
Makes the North look much larger

7. Gall-peters projection

8. Gall-peters projection
Focuses more on land area accuracy
Released in 1974, based off a 1800 design
More accurately shows southern hemisphere as larger than northern hemisphere
Areas near the poles are stretched horizontally

9. Goode Homolosine projection

10. Dymaxion projection

11. Types of maps

12. Maps as a tool to understand spatial patterns
Maps can give insight to how a phenomenon is occurring and provide the starting point for understanding the why
Example: A doctor figures out why a group of specific people are getting cholera by using a map to see they were all living in the same general area and using the same water pumps, which were causing the cholera outbreak

13. Choropleth maps
A map showing quantity by area. It uses shades of colors to show intervals

14. Isoline maps
A map that is used to display distributions. It consists of lines that connect to show equal value

15. Proportional (graduated) circle maps

16. Dot maps

17. Caution: maps can be deceiving!
Every map is flawed in some way
Cartographers can be wrong, include inaccurate data, or make you perceive something differently that they want you to see by distorting the map

18. Glancing at that map, we’d think California, Texas, Florida, and New York were horribly dangerous places to live
The problem is that we’re basically looking at a map of population. Of course the more people live in a place, the more crimes (all else being equal) will be committed there

19. These maps, from ads for Verizon Wireless, show 3G network coverage by Verizon and AT&T. The impression they give is that most of the US isn’t covered by AT&T at all
BUT if you look at the map of population density, you will see that areas with the most people are covered