Population Dynamics
Population Dynamics
Birth Rate, Death Rate, and Natural Increase
- Birth rate is the number of live births per 1,000 people per year.
- Death rate is the number of deaths per 1,000 people per year.
- Natural increase is calculated by subtracting the death rate from the birth rate (it does not include immigration or emigration).
Population Density and Distribution
- Population density is determined by the number of people living in a unit area, generally per square kilometre or square mile.
- Populations are not evenly distributed. Some places are densely populated while others have sparse populations.
- Population distribution can be influenced by factors such as climate, terrain, availability of resources, political, social, and economic factors.
Demographic Transition Model
- The Demographic Transition Model (DTM) is a model that represents the transition from high birth and death rates to low birth and death rates as a country develops.
- The pattern is typically split into four stages: high fluctuating, early expanding, late expanding, and low fluctuating.
Population Pyramids
- Population pyramids are graphical representations showing the distribution of different age groups and genders in a population.
- It can help to understand the structure of a population. They are usually used to compare changes over time or differences between countries.
Migration
- Migration refers to the movement of people from one place to another.
- It can be internal (within a country) or international (between countries).
- Migration can be influenced by pull (attractive) and push (repelling) factors.
- It alters population distribution and can impact both the area people leave from and the area they move to.
Ageing Population
- An ageing population happens when the median age of a country or region rises due to rising life expectancy and/or declining birth rates.
- It can cause shifts in healthcare needs and economic structures.
Overpopulation and Underpopulation
- Overpopulation occurs when a population exceeds the carrying capacity of the environment, leading to resource depletion, environmental degradation, and potential starvation and disease.
- Underpopulation is a situation where there are too few people to effectively use the available resources and maximize the potential economic development.
Use these points to form the basis of your revision notes on Population Dynamics. Understand each concept, find examples and practice related questions to test your understanding.