GNP - Introduction to Mapping Lesson
Geography: Its Nature and Perspectives
Introduction to Mapping
Mapping
No map can accurately show the Earth. Different projections attempt to demonstrate one of the four main characteristics reliably while allowing distortion to occur in another area:
- Shape
- Area (Size)
- Distance
- Direction
Map Projections
- Transferring 3D globe to 2D map causes distortion
- Shape, Area (Size), Direction, Distance
- Mercator – Direction is accurate, but area is distorted on rectangular grid
- Molleweide – Area is true, but straight lines of latitude distort the shape
- Robinson – Equally distorts all four aspects
- Goode's Homosline – Maintains area, but divides oceans which distorts distance
- Fuller – Maintains shape and area but loses direction
- Peters – Maintains area, but distorts shape
Map Projections Slides
See examples in the photobook below. Turn the pages by selecting on the arrows under each page.
Purposes
Maps usually show a specific area, but can also be used for demonstrating geographic trends.
- Reference maps (roads, mountains, etc)
- Thematic (show trends)
- Proportional symbol, cartogram, choropleth, dot-density, flow-line, isoline, etc.
Map Purposes Slides
See examples in the photobook below. Turn the pages by select the arrows under each page.
IMAGES CREATED BY GAVS
(Images in photo book #1 are available in the Public Domain via Wikimedia Commons; Images in Photo Book #2 - Proportional Symbol Map - Image by Tony Hirst, via Flickr; Cartogram - Image by Philippe Rekacewicz; Choropleth and Isoline are available in the Public Domain via Wikimedia Commons; Dot-density map - Image by Eric Fischer via Flickr; Flow-line Map via Stryder.com)