HASS Geography T2

sustainability

ongoing capacity of Earth to maintain life by managing resources so they can be maintained for future generations.

degradation

damaging effects human activities have on the physical environment meaning the quality of features are being negatively affected

deforestation

clearing of forested areas for timber and farming like in South America. Results- loss of habitat, biodiversity, drop in oxygen production, increase carbon dioxide

Soil salinity

land degradation- particularly in Australia caused by extensive clearing of native vegetation which leads to the rising of groundwater levels- brings salt to the surface

air degradation

reduction in the quality of the atmosphere. human activities like burning of fossil fuels has led to high levels of pollution.

water degradation

pollution of oceans and waterways

air pollution causes

• Increased since Industrial Revolution (1750–1914)-

• sources: industries, households, vehicles

• Burning fossil fuels increases:

  • carbon monoxide

  • nitrogen oxides

• Livestock farming increases methane

Air pollution effects

• asthma

• cardiovascular disease

• Children, elderly and poorer communities most at risk

• 90% of deaths- low-income countries

• Causes enhanced greenhouse effect

  • global warming

  • climate change

  • melting ice caps

  • rising sea levels

Ozone Layer

• protects Earth from harmful UV radiation

• CFCs (chlorofluorocarbons) found in:

  • aerosols

  • refrigerators

  • air conditioners

• rise into atmosphere, React with sunlight to form chlorine- destroys ozone molecules

• greatest over Antarctica- extremely low stratospheric temperatures

• Allows more harmful UV radiation to reach Earth

Acid Rain formation

• Sulphur dioxide and nitrogen oxides enter atmosphere

• React with water and oxygen

• Form diluted:

  • sulphuric acid

  • nitric acid

• Falls as acidic precipitation- diluted

Acid rain sources and effects

• volcanoes

• burning fossil fuels for electricity

• vehicles

• manufacturing industries

Effects:

• increases soil, water acidity

• damages vegetation, ecosystems, structures

• pollutants can be carried long distances by wind

Coastal landscapes and degradation

where the ocean or sea meets the land

• Affected by natural processes and human activities

• Australia highly affected bc:

  • most population lives near coast- places pressure on coastal environments

  • Aus capitals located on coast

Beaches and impacts

• Flat areas of: sand, shells, pebbles near shoreline

• severe storm waves cause erosion

• Gentle Waves build up beach by depositing sediment

Human Impacts

• Littering

• Pollution

• Urban development

• Habitat destruction

• eg. Indiana Teahouse, Cottesloe Beach

Erosion, deposition, longshore drift

erosion- wearing away of coastal landforms by wind and water

deposition- building up of particles

longshore drift- transportation of particles in zig zag motion down beach, depositing sediment

Dunes and human impacts

hills of sand directly behind the beach. created when wind and waves deposit particles.

Human impacts:

• Walking off pathways damages vegetation, exposes sand to erosion

• Residential development destroys dune systems

• Causes loss of plant and animal species

Types of genes

Foredunes:

• smallest closest to beach

• no vegetation, unstable

• impacted by erosion

Primary dunes:

• First large dunes

• grasses and shrubs

• More stable

Secondary dunes:

• large shrubs and small trees- stabilised

• Less affected by wind erosion

Tertiary dunes:

• Oldest, most stable

• variety of vegetation

Climate change impacts on coastal landscapes

• Rising sea temps and levels

• Coral bleaching

• Increased storm intensity

• Threatens ecosystems, economies, coastal communities

Rising sea temperatures

• Oceans absorb excess heat from atmosphere- greenhouse gas emissions

• Places stress on marine ecosystems

• Major cause of coral bleaching

coral bleaching, importance, examples

• when water becomes too warm, corals expel algae living inside - turn white

• Lose food source

• May die if temp remain high

Importance

• Protect coastlines from erosion

• Habitat

• Support tourism, fishing industries

Eg

• Great Barrier Reef

• Ningaloo Reef

Rising sea levels and effects

• Melting glaciers, polar ice caps

• Expansion of warmer seawater

Effects

• coastal areas at risk

• Coastal flooding, erosion

• Damage to homes, infrastructure, farmland

• Saltwater contamination

• Threat to low-lying regions, small island nations

increased storm intensity

• Warmer oceans provide more energy to

  • tropical cyclones

  • hurricanes

  • typhoons

• Causes:

  • stronger winds

  • heavier rainfall

  • larger storm surges

• Increases coastal erosion

• Damages buildings, roads, ports

coastal management

strategies used to control the effects of natural processes, such as erosion, and human activities. Divided into hard and soft engineering

Hard engineering

methods of coastal management

• Requires major construction

• expensive

• Does not blend naturally with environment-noticeable

Rock armour

• placement of large rocks parallel to beach

• Reduces wave erosion

• Holds sediment in place

• Durable

• Expensive

• Unnatural appearance

sea walls

• Stone, brick or concrete walls-held by cement behind beach

• Very effective against erosion

• Long lasting

• Expensive

groynes

• Structures made from stone, concrete, wood built 90° to shoreline

• Trap sand

• Build up beaches

• stop longshore drift

• Can increase erosion further along coast

gabions

• structures of stones held by wire mesh

• faster and cheaper than sea walls

• Less durable

artificial reefs

• Offshore submerged structures made from rocks, steel or concrete, old ships

• Reduce wave erosion

• Create marine habitats, diving sites

soft engineering

methods of coastal management

• Works with natural processes

• Less construction, expense

• More sustainable and attractive than hard engineering

Beach replenishment

• Sand quantities added to beaches using machinery, aka beach nourishment

• Natural appearance

• assists natural deposition processes

cliff regrading

• Reducing steepness of areas prone to heavy erosion then vegetated to keep soil in place

Enhanced greenhouse effect

• greenhouse gases retain heat in atmosphere

• natural greenhouse effect keeps Earth warm

• human activities increase gases

  • carbon dioxide

  • methane

  • water vapour

• causes global warming, climate change- temps too high

• rising sea levels, melting ice caps