Topic:

Presenter: Daniel Griffith

As a country experiences transition from third world to first world status, its territory tends to become increasingly organized in a hierarchical fashion. The hierarchical organization promotes efficiency within in the country, including facilitating flows between locations and administration of health services. The hierarchy almost always is reflected by the organization of a country's urban places.

The chance of a diffusion materializing increases as the size of the population residing at a location increases (a hierarchical component), and decreases as the distance separating the two locations increases (a contagion component). This diffusion pattern may be described with a social gravity model.

Some of the issues addressed include

• Mechanisms that create geographic hierarchy (e.g. air travel).
• What factors lead to hierarchical versus contagious diffusion?
• Predicting "where" when diseases leap from place to place.

OBJECTIVES: Those who successfully complete the module should

• have a better understanding of how communicable diseases move through human populations in mobile societies (becoming increasingly important as a society develops economically).
• have an appreciation of how the diffusion is numerically and mathematically conceptualized; how the movements between places are characterized.
• have a space/time data set that they may study and analyze at their leisure.

• SCENARIO 1
• SCENARIO 2