ess topic 8

crude birth rate (CBR) formula

No. Of Births/total population X 1000

Crude Death Rate (CDR) formula

No. Deaths/total population X 1000

total fertility rate

the average number of children a woman is expected to have during her lifetime, based oncurrent age-specic fertility rates

life expectancy

This is the average number of years a person is expected to live from birth, assuming currentdemographic factors (such as healthcare) remain the same

doubling time + formula (must know)

This is the number of years it would take a population to double in size, based on its current growth rate.

natural increase rate + formula (must know)

This is the dierence between the crude birth rate and crude death rate, usually expressed as apercentage or a number per 1 000.

If the birth rate is higher than the death rate, natural increase occurs

UN projection models (3)

direct management of population growth (3)

anti-natalist: reduce birth rates in countries with high population growth. These policies are common in countries facing overpopulation, where resources are strained. ex: China’s one child policy.

pro-natalist: encourage an increase in birth rates in countries with low or negative populationgrowth. These policies are used in countries facing ageing populations or labour shortages, ex: Sweden provides parental leave to support family growth.

migration policies: manage immigration and emigration to influence population size and labour markets. ex: Germany encourages immigration to offset declining population.

indirect management of population growth (3)

economic policies: improving living standards + changing family planning decisions. ex: improved employment opp can reduce poverty —> less children + higher living standards.

social and gender equality policies: reduce birth rates by empowering women and girls. ex: education for girls and women —> delayed marriages and childbirth —> improved gender equality

public health and welfare policies: lowering death rates and improving overall well-being. ex: improving healthcare —> reduce infant mortality —> smaller family size + stable populaiton growth.

age-sx pyramids.

different types of age-sx pyramids

1. low-income countries (LICs)

2. more developed LICs

3. high-income countries

demographic transition model + relationship with age-sx pyramids

urban ecosystem’s components

ecosystems have both biotic components (living organisms like plants, animals and humans)and abiotic components (non-living parts like soil, water, air and urban infrastructure).

urban areas + its types

An urban area is a built-up area with a high population density, buildings and infrastructure. Cities, towns and suburbs are classified as urban areas.

difference between urban and rural areas (in terms of population density, infrastructure, and ecosystem types)

Urban areas have a dense assemblage of buildings and people located close together for residential, cultural, productive, trade and social purposes;

rural areas have relatively low population density and dispersed settlements.

what is an urban system

it is a network of interconnected elements that work together to support life in a city or town

urban waste/pollution, urban efficiency, urban sustainability, urban resilience

urban system flow diagram (linear and circular metabolism)

urbanisation

the process where a growing proportion of a country's population moves from ruralareas (countryside) to urban areas (cities and towns)

rural-urban migration, push-pull factors

rural-urban migration, forced and voluntary migration + deurbanisation trends

suburbanization

Suburbanisation is the process where people move from the dense central parts of cities (urbanareas) to the less dense, peripheral areas (suburbs).

It involves the expansion of cities into nearby rural or undeveloped areas, creating lower-densityresidential areas

urban sprawl

Urban sprawl refers to the uncontrolled expansion of urban areas into surrounding rural land, creatingspread-out developments.

Urban sprawl is closely related to suburbanisation, as lower-density housing and commercial developments require more land, stretching the boundaries of the city

environmental impacts of urban expansion → agriculture

environmental impacts of urban expansion → water

environmental impacts of urban expansion → air

environmental impacts of urban expnasion → biodiversity

urban planning + factors in sustainable urban planning

Urban planning is the process of designing how land and buildings in a city are used to meet the needsof the population

It focuses on the best way to organise urban space to meet the physical, environmental,commercial, industrial, and social needs of all residents

ecological urban planning components:

urban ecology: green spaces and natural habitats into city design

urban farming: growing food withinc ities

biophilic design: brings nature into the built environment (natural elements into architecture)

resilience planning: designing cities to withstand and adapt to env changes

regenerative architecture: reduce env harm but actively improve the env

what causes urban air pollution

it is caused by inputs from human activities to atmospheric systems, including nitrogen oxides (NOx), sulfur dioxide, carbon monoxide and particulate matter.

PM2.5: ne particles with a diameter of 2.5 micrometres or smaller; PM10: larger particles with a diameter of 10 micrometres or smaller

primary pollutants + their sources

primary pollutants are directly emitted from a source + immediately active in the atmosphere.

natural sources: come from natural events (eg forest fire, volcanic eruptions, dust storms)

anthropogenic sources: human activities (eg burning fossil fuel, agricultural burning, industrial processes)

secondary pollutants

Secondary pollutants are not emitted directly but form in the atmosphere when primary pollutantsreact with other chemicals

eg tropospheric ozone

air pollution management strategies

reducing the use of fossil fuels → promote renewable energy sources; improve public transport; cycling

emission zones and car restrictions → Low Emission Zones (LEZs) restrict high-polluting vehicles, reducing air pollution in the city centre

catalytic converted → fitted to car exhaust systems to reduce harmful emissions

growing trees and natural screens → trees absorb co2 and trap particulate matter; natural screens like hedges reduce pollutants near roads and buildings

green walls and green roofs → covered w vegetation to improve air quality and regulate temperature (reducing urban heat island effect)

acid rain formation + chemical formula to form acid rain

occurs when NOx and sulfur dioxide react with water and oxygen in the air to produce nitric and sulfuric acid, resulting in acid rain.

impacts of acid rain on ecology

terrestrial habitats:

• accelerates leaching of essential nutrients from soil, leading to nutrient deficiencies

• increase soil toxicity

• direct damage to foliage (weaken trees)

• coniferous forests are sensitive to acid rain, inhibits nutrient absorption

freshwater habitats:

• water bodies become more acidic because of solubilisation of aluminium

• aluminium is toxic to aquatic life (make fish harder to breath, or exoskeleton inidviduals have difficulty in maintaining their shell)

impacts of acid rain on buildings and infrastructure

corrosion of construction materials:

• acid rain erodes materials like marble, limestone causing it to corrode and weaken

impact of acid rain on human health

respiratory issues:

• nitrate and sulphate particles can cause respiratory problems

• particulate matter can enter lungs and increase risk of asthma, lung inflammation, etc

acid rain management strategies

altering human activity: using alternative energy sources

controlling at the point of release: scrubbers and catalytic converters

restoring the damaged systems: healthcare and adding limestone/fertilizer to lakes