What Geographic Factors Affect the Spatial Distribution of Ebola - - PowerPoint PPT Presentation

Song Gao Email： sgao@geog.ucsb.edu STKO Lab, Department of Geography

What Geographic Factors Affect the Spatial Distribution of Ebola Virus Disease in West Africa

http://www.geog.ucsb.edu/~sgao/

2014 GIS Day

Ebola by the numbers: The size, spread and cost of an outbreak by Declan Butler & Lauren Morello

http://healthmap.org/ebola/#timeline

Correlation Coefficient: 0.722

Distance to Street Nodes and Edges

Distance to Street Nodes and Edges

• 63% case locations within 10 km buffer zone
• 81% case locations within 20 km buffer zone
• 95% case locations within 30 km buffer zone of the

highway junction nodes

• 85% -> 10 km buffer zone of streets
• 93% -> 20 km buffer zone of streets

Network Centrality

 Sociology Scientist, Freeman (1979)

 Degree Centrality  Closeness Centrality  Betweenness Centrality

 Geographers, Porta et al. (2006); Gao et al. (2013)

 Street Closeness Centrality  Street Betweenness Centrality  Street Straightness Centrality

Betweenness Centrality

It measures how often a node is traversed by the geometry shortest paths connecting all pairs of nodes in the street network.

Information, Communication, Technology & Space, Place & Social

Complex Networks Human Mobility Spatial Structure

• Population distribution
• Facility Distribution
• Digital Elevation Model
• Movements
• Mobile Phone Call
• Interactions
• Functional region
• ……