Tuesday, May 27, 2014

Visualising and modelling population change

 Image above: The Demographic Transition Model (DMT)

Related links to Spatialworlds 
Spatialworlds website

Australian Geography Teachers' Association website

Population change as time goes by

Populations, including the demographic variables of total number of people, age breakdown, sex ratios, birth rates, death rates and rate of growth are not static but change over time as the conditions in a country change for the better or worse. In most countries, such change involves development and the associated improvements in health and social conditions as a result of industrialisation and economic improvements in a country. The following sites attempt to explain the modelling and subsequent visualising of such changes over time via the DemographicTransition Model (DMT). The DMT is a model that describes a predicted and in most cases expected population change over time. It is based on an interpretation begun in 1929 by the American demographer Warren Thompson, of the observed changes, or transitions, in birth and death rates in industrialized societies over the past two hundred years or so. Although not perfect and as always there ar exceptions to the model (rule), the DMT over the years has been frequently used by demographers as a visualisation of the way population changes over time as  a result of economic development. In fact, the task for students to find those exceptions to the model is quite a valid and creative way to use the model to understand the demography of population change. For example, an exception to model is when a country is still developing and have a religious imperative for keeping birth rates high OR they have a national crisis such as war or disease that is keeping life expectancy low. A few examples are conflicts in Afghanistan or the AIDS crisis in Sub-Saharan Africa.

* Video explaining the demographic transition model

* Videos explaining the impact of development on a countries population and the Demographic Transition Model (DTM)

* A detailed look at the stages of the DMT

* A good summary of the DMTstages

* A summary video of DMT

* Worth looking at the Age-Sex Pyramid animation showing the movement through the stages of  the DMT (from youthful population to the ageing population).

 * Youthful and Ageing populations

* Youthful population video

* Ageing population video

* More animations to aid understanding (simple, a little annoying but useful)

* How many people?

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