Nat 5 geography (rivers, population, natural disasters) Flashcards
Formation of features in the river
Formation of a v-shaped valley
- River in upper course
- Vertical erosion (hydraulic action and abrasion)
- Deep notch in landscape exposes sides to freeze thaw
- sides get weak and fall into the river (further abrasion)
- Rocks transported downstream
- V-shape valley is formed weaving around interlocking spurs
Formation of a meander
- Middle/Lower course
- Lateral erosion
- River has deep and shallow parts
- River fastest on outer bend eroding it making it deeper (hydraulic action + abrasion). Forms River cliff.
- River is slowest on inside of the bend making it shallower (deposition- dropping of the load). Forms river cliff
Formation of a waterfall
- Upper course
- Water flows over bands of hard and soft rock
- Soft rock eroded quicker than hard
- Erosion creates a plunge pool where the water hits, undercutting the hard rock (hydraulic action + abrasion)
- Hard rock collapses leaving waterfall and a steep sided gorge
Formation of an ox-bow lake
- Middle/Lower course meanders
- Deposition on inside of bend due to slow current
- Erosion (hydraulic action + abrasion) on the outside of bend due to fast current.
- Neck gets narrower as river cliffs meets
- When river has power it takes shorter route over the neck.
- Deposition eventually blocks of the meander bend from the main river leaving an ox-bow lake
Formation of levees
- Levees are natural embankments
- Middle/ lower course
- Times of low flooding river deposits on the river bed raising its height.
- Times of flood river flows over the edge and deposits heavy material on the side of the river.
- Each flood builds up the levees.
High population density (MEDC’s) due to..
Moderate climate fertile farming land low land clean water supply mineral resources good infrastrucutre
low population density (LEDC’s) due to..
Extreme climate extreme relief extreme remoteness infertile land no clean water supply
human factors that affect population
transport and communication jobs government investment quality of housing education healthcare
Physical factors that affect population
relief climate vegetation soils natural resources water supply
Reasons for high birth rate (LEDC’s)
- children needed for workers and to look after elderly
- no family planning or contraception
- many religions frown upon women using birth control
- high infant mortality means many families have back up children
- high status for men if they have a large family.
Reasons for low birth rate (MEDC’s)
- it is expensive to have children
- more women focus on careers
- sexual equality means women choose what they want
- contraception and family planning is widely available
- children are not need for elderly care
Reasons for high death rate (LEDC’s)
Dirty unreliable water poor housing conditions poor access to medical services endemic diseases poor diets that are low in calories or protein
Reasons for low death rate (MEDC’s)
Good housing conditions
safe water
enough food to eat (stronger immune systems)
advanced medical services that are available to all.
how to deal with a rapidly growing population(LEDC’s).
educate about family planning and contraception
extra taxes for parents with large families
rising the age of marriage
Extreme ‘one child policy’
how to deal with an ageing population (MEDC’s)
Giving mothers longer paid maternity
generous child benefits
raise retirement age
Japanese Earthquake
Impact on the Landscape (3)
- Shaking ground cause landslides
- Gas pipes and cables damages causing fires
- Tsunami swept 10 km inland destroying everything
- Fukushima 6 reactors were very hot and needed to be cooled. Cooling systems stopped working due to power cuts. Emergency generators kicked in but were flooded by the tsunami. Reactors 1,2 and 3 experienced a full meltdown. Releasing radiation
Japanese earthquake
Impact on the people (3)
- Earthquake + tsunami killed 19,000
- Power shortages for days
- 500,000 left homeless
- Radiation from increased the risk of cancer by 1% in locals
Japanese Earthquake
Aid recieved
- USA gave $100,000 and 2 search and rescue teams
- India gave woolen clothes and blankets
- Germany gave search and rescue rapid eye satalite imagery
Planning for an earthquake, Give examples (6)
Earthquake detection system
Earthquake and tsunami drills
Tsunami warning
Earthquake proof buildings
Safety measures- water sprinklers, gas cut off valves
- used in Japan, California, San Andreas fault line
Mt St Helens
Impact on the landscape (3)
- Landslide buried the North folk Toutle river
- The blast and the pyroclastic flow killed everything 25km north of the volcano
- 7000 animals died
- Mudflow choked the river killing 12 million salmon
Mt St Helens
Impact on the people (3)
- 90% of people killed were outside the the exclusion zone.
- 57 people died
- 198 were rescued
- People swept away by lahars
- Ash made the soil infertile costing farmers
Mt St Helens
Aid recieved
- $145 million was given by US government
- New salmon hatcheries
- $50 million was spent on a Mt St Helen visitor centre
- Millions of trees were replanted
Planning for a volcanic eruption (6)
Hurricane Katrina
Impact on the Landscape (3)
- $1.5 billion worth of damage in Southern Florida
- Torrential rain (350 mm in some areas)
- New Orleans flooded under 6m
- 200 km/h winds Louisiana
- Mississippi 8 m waves destroyed houses
Hurricane Katrina
Impact on the people (3)
- Killed 1836 people
- Most people drowned in the flood or collapsing building
- Many had to be rescued from rooftops
- 1 million made homeless
- hundreds of thousands of people were left unemployed.
Hurricane Katrina
Aid received
- Aid was received from charities
- President Bush gave $110 billion to rebuild homes and lives but only $44 billion has been spent.
- UK and china sent rescue workers immediately
- Pakistan sent doctors
Planning for a Hurricane (6)
- Hurricane preparedness week
Plenty of warning was given to the possible locations that could get affected
90% of New Orleans had left the city
Those left used the super dome for safety.
Physical factors affecting climate change.
Solar radiation Earths tilt, stretch and wobble Volcanic eruptions Plate tectonics Ocean currents
Human factors affecting climate change.
Increased burning of fossil fuels, in cars deforestation paddi fields belching cows landfills
Negative impact of climate change (3)
ice caps will melt causing sea levels to rise
rising sea levels will flood coastal ares such as Bangladesh and even flood entire islands (Maldives)
deserts may begin to spread due to land becoming to dry (Sahara desert)
this also means severe droughts in places like africa
Positive impacts of climate change
Arctic and Antarctic have milder climates allowing people and animals to live.
Less sea ice means it is easier to transport by boats
Warmer temperatures in UK means a longer growing season and a increased crop yield.
