Hägerstrand's Diffusion Model

Question 1

Important concepts of Hägerstrand’s Diffusion Model

Answer 1

• A neighbourhood effect: the probability of contact between those infected and those not infected and the influence of decay
• The number of people infected: represented by an S-shaped curve over time
• The interruption of the progress of a disease by physical barriers

Question 2

Primary (1st) stage of Hägerstrand’s Diffusion Model

Answer 2

There is a strong contrast in disease incidence

between the area of outbreak and remote areas

Question 3

Diffusion (2nd) stage of Hägerstrand’s Diffusion Model

Answer 3

New centres of disease outbreak occur at distance from the source and this reduces the spatial contrasts of the primary stage

Question 4

Condensing (3rd) stage of Hägerstrand’s Diffusion Model

Answer 4

The number of new cases is more equal in all locations, irrespective of distance from the source

Question 5

Saturation (4th) stage of Hägerstrand’s Diffusion Model

Answer 5

Diffusion decelerates as the incidence of the disease reaches its peak

Question 6

Physical barriers of disease diffusion

Answer 6

Distance, mountains, sea, deserts, climatic change or general climatic conditions such as tropical or continental

Question 7

Socio-economic barriers of disease diffusion

Answer 7

Political border checks, imposition of curfews or quarantining. Most of these are put in place by international organisations and/or governments