Maps and Spatial Understanding
• The primary influences over the level of interaction are the size of the two cities and the
distance between the cities. (bigger the cities = more interaction, smaller the distance =
• The distance decay function changes the level of interaction between the two cities.
• The distance decay function should vary among cities because the levels of
accessibility/connectivity also fluctuate.
Maps are two dimensional graphical representations of the world, and they depict spatial
• Communicate information
• Analysis of spatial information (made by individuals or companies, subjected to bias)
• Socially constructed
• Maps are challenging because we are trying to portray a 3D globe on 2D
Projection is a mathematical technique for representing a 3D sphere on a 2D map.
• Put a paper on the surface of the earth, and shine a light bulb on it. Shadows become
the continents. Perfect reflection for the images touching the paper, but there is a
distorted image for the images further away from the paper.
• Three types of projection; all have varying levels of accuracy and the main forms of
distortion are from distance, direction, and the area.
1. Cylindrical projections are projected onto a cylinder that touches the outside
edges of the globe. The paper is wrapped around the globe.
• Accuracy is greatest at the Equator and declines as you move towards
the North and South Poles.
2. Conical projections are projected onto a cone that
touches the outside edges of the globe. The cone
sits on the mid-latitudes.
• Accuracy is greatest in the mid-
latitudes, and it declines as you move towards the two poles.
3. Azimuthal projections are projected onto a flat surface that touches the globe at
one single poin