ESS unit 8

Demographic variables

Demographic tools for quantifying human population include:

Crude birth rate （CBR)

Crude death rate (CDR)

Total fertility rate (TFR)

Doubling time (DT)

Natural increase rate (NIR)

Crude birth rate

Total number of births/ Total population x100%

Total fertility rate

The average number of births per woman of childbearing age.

LEDCs have highest fertility rate

MEDCs tend to have lower fertility rate

Crude death rate

The number of deaths per thousand people in a population.

Factors that affect TFR

Level of education

Material ambition

Political factors

Family planning

Variations in mortality rates

Age structure

Social class

Occupation

Place of residence

Natural increase rate (NIR)

It is calculated by subtracting CDR from the CBR

Doubling time (DT)

The number of years needed for a population to double in size, assuming the natural growth rate remains constant.

70/NIR

The demographic transition model stage 1

High and variable

Birth and death rates are high

Population growth fluctuates

The demographic transition model stage 2

Early expanding:

Birth rate remains high but the death rate comes down rapidly.

Population growth is rapid

The demographic transition model stage 3

Late expanding

Birth rate drops and the death rate remains low

Population growth continues but at a smaller scale.

The demographic transition model stage 4

Low and variable

Birth rates and death rates are low and variable

Population growth fluctuates

The demographic transition model stage 5

Low declining

The birth rate is lower than the death rate

The population declines

Age sex pyramids

A wide base indicates a high birth rate

Narrowing base suggests falling birth rate

Straight or near vertical sides indicate a low death rate

Concave slopes characterize a high death rate

Bulges in the slope suggest baby rooms or high rates of immigration

Slices in the slope indicate emigration

High birth rate

A wide base

Falling birth rate

Narrowing base

Low death rate

Straight or near vertical sides

High death rate

Concave slopes

High rates or immigration

Bulges in the slope

The demographic transition model

Shows the change in population structure from LEDc to MEDcs

Influence on human population dynamics

Cultural

Historical

Religious

Social

Political

Economic

National population policies

Official government actions to control the population in some way.

International development plans

The Millennium Development Goals (MDGs)

Eradicate poverty and hunger

Promote gender equality

Reduce child mortality

Ensure environmental sustainability.

Renewable natural capital

It can be generated or replaced as fast as it is being used.

Non renewable natural capital

Can only be replaced over geological time scale.

Types of ecosystem service

Supporting services:

-Primary productivity and the cycling of nutrients

Soil formation

Regulating services:

regulation of pests

Production of goods such as food

Provisioning services:

People obtain from ecosystem such as food, fuel and water.

Cultural services:

Education

Recreation and tourism

People interacts with nature

Dynamic nature

There are possibility that its status may change over time.

Electronic waste

The increase in e-waste is happening because there is so much technical innovation.

Composting

The decomposition of biodegradable material. It recycles organic household waste into a humus like soil. It give nutrients to the soil.

Disposal options for SDW

Landfill, incineration, recycling and composting

Landfill

It is cheap but it is not always healthy. And will runout.

Will have the risk of health problems:

Heart problems

Birth defects

Incineration

Burning

The heat can be used to generate electricity.

Dis:

Air pollution: carbon dioxide, sulfur dioxide, nitrogen dioxide

The volume of traffic generated to move the waste to the incinerator.

Strategies for managing SDW

Cultural

Economic

Technological

Political barriers

Altering human activity:

Reduction of consumption and composting of food waste

Controlling release of pollutant: