Geo-Spatial Analysis

Data Literacy

Geo-Spatial Analysis

Summarizing Reality

• Data attempts to summarize reality.
• Limits in that summarization.
• Problem = particularly clear with geospatial.

The Basics: Latitude and Longitude

• Longitude = X axis
  • Measures distance from east to west
• Latitude = Y axis
  • Measures distance north to south.

Why Projections are needed

• What is a projection?
• What is the issue with projections?
• Representing a 3d globe in a 2d plane

The Basics: Projections

• Projections are the way that we project 3d orientation to 2d.
• Standard Web projection is the Web Mercator: 3857

Projection Problems: Mercator Map

Mercator Projection

Projection Problems: Gall-Peters Projection.

Gall-Peters Projection

Projection Problems: Goode-Homolosine Projection

Goode-Homolosine Projection

Other problems: Calculating Coastlines

• What is the coastline paradox?

Coastline Paradox, cont.

Coastline Paradox, cont.

Types of Maps: Placial and Spatial

• Placial map
  • A map where the physical space occupied is not the central concern.
  • Frequently attempts to summarize the data further for greater clarity.
• Spatial map
  • A map where the occupied space is the central concern

Placial Map

Metro Map: Placial

Spatial Map

US population Map