geography Flashcards
(30 cards)
Describe the global heat budget
18% absorbed by gases, 20% reflected by clouds, 6% reflected by atmosphere, 6% reflected by surface (Albedo effect)
Give an example of a cold current and a warm current
Cold - Labrador
Warm - Gulf + North Atlantic
Why do density differences occur in water at the poles compared to the equator
Differential heating and/or salinity means cold water sinks and spreads to the poles displacing warm water at the equator
How does a v shape valley form
Rivers in upper course have high energy, as it is steeper, causes vertical erosion to dominate. Hydraulic Action (water pushes air into cracks in the rocks, compressing it, weakening the rock) is common due to water turbalence. This erodes bed of river, leaving valley sides unsupported. Weathering loosens rocks and soil on banks which then collapses into the river, due to gravity. This is known as mass movement. The material in the river hits against the banks causing abrasion. Material that has fallen through mass movement will remain until the river has enough energy to transport them away (eg through saltation) As the river erodes downwards, it creates the V shape. The river travels down the path of least resistance, avoiding hard rock, creating bands of interlocking spurs.
Describe the formation of a waterfall
They form where more resistant rock overlies less resistant rock. As water flows over these, they undergo differential erosion. River erodes softer rock through abrasion. Water increases in speed due to the vertical drop and further erodes the softer rock through hydraulic action so an undercut develops. Resulting debris is swirled around creating a deep plunge pool, undercutting further. An overhang of harder rock is created. This is unstable as it is not supported and over time it collapses. Eroded material in plunge pool is broken up through attrition (rocks hit against each other, making them smaller and more rounded) and is deposited/carried away by river. Any remaining material may create potholes in the pool. Processes continue for thousands of years, pushing waterfall further upstream, creating a steep sided gorge.
Describe meanders
A meander is a bend/loop/turn in a river. Meanders form in the middle/lower courses of the river, where the valley is wide enough for lateral erosion to occur. Over time, they become more pronounced and can change the course of the river.
Describe a ox-bow lake
Ox-bow lakes form in the lower course, where the valley is very wide. They form from meanders. Helicoidal flow means the rivers fastest flow is on the outside of the meander where the water is deepest and there is little friction. As outer banks of meader are eroded though hydraulic action, the neck of the meander grows narrower. Eventually during flooding, when the rivers energy is at it’s greatest, the river cuts through the meander’s neck, making river straighter. The fastest current will now flow through centre of the straighter channel and deposition will take place in the shallower, slower moving water. Due to the deposition, the meader will be cut off and left as an ox-bow lake. Due to lack of water supply, the lake may fill up with sediment and dry up due to infiltration and evaporation.
Describe a podzol soil
LL: Pine needles and cones
Humus: Acidic
A: Leaching occurs, pale ash-grey colour as iron oxides are leached, course sandy texture. No animals/distinct horizons
B: Dense, red brown colour, iron pan
C: Acidic rocks, chemically/physically weathered, glacial till
Describe brown earth soil
Ao: Decidious vegetation, mull humus
A: well-mixed (Earthworms), tree roots aerate soil, leaching is minimal, dark brown
B: Lighter due to less organic content
C: Chemical/Biological weathering
Describe a gley soil
Ao: Dead grass, acidic mor humus
A: Dark grey, well defined horizons, waterlogged soil
B: Blue/grey colour, micro organisims find oxygen in iron oxides causing colour change
C: impermeable, prevents draingage, chemical weathering
Name problems associated with youthful populations
- significant investment needed in paedratric care
- more schools/teachers needed
- high pressure on healthcare
- housing is crowded, more people in shanty towns
- high levels of unemployment/underemployment
- government policies may encourage small families/migration
name problems associated with an elderly population
- increase in pensions
- retirement age may increase, more carehomes needed
- increased strain on healthcare
- skills gap due to decrease in economically active people
- high demmand placed on children to care for elderly parents
- lowers demmand for childcare/nurseries problems for those industries
Name causes of land degradation
- unpredictable climates
- soil easily dries out or is blown away
- increased need for timber has caused mass deforestation
- concentration of livestock strips vegetation, leaving soil exposed
- increased demmand for food results in farming on marginal land, land cannot recover or regenerate
Name consequences of land degradation
- crop failure/death of livestock leading to malnutrition
- farmers lose income due to crop failure, unable to afford basic needs
- widespread poverty leads to dependance on overseas aid
- in last 50 years, 65 million hectares of sahel have turned into desert
- poverty/hunger forces people into urban areas, putting pressure on urban resources increasing shanty towns
Name methods of managing land degradation
- planting new trees to bind soil and hold it in place
- increased crop rotation allows soil to recover
- planting drought resistant plants to help bind soil and prevent further soil erosion
- large and small scale irrigation schemes
- reduce herd sizes and controlling grazing to protect vegetation
Name problems of traffic congestion
- increase in cars leads to higher levels of air pollution
- inadequet/costly public transport leads to increase in private/commercial vehicles
- cities with old, narrow roads cannot handle increased traffic
- shortage of parking facilities leads to cars parked on main roads
- Developing countries cannot spend money on infrastructure leading to roads in disrepair
Management strategies for traffic in developed city
- building city bypass
- lez zone
- multi-story car parks to reduce cars on the street
- improved public transport, free wifi on bus
- park and ride
- bus lines
- tram
Management strategies for traffic in developing cities
- yellow line expressway
- bus rapid transit
- rio-niteroi bridge
- bike rio
- metro line upgrades
- gondola system
Problems in housing edinburgh
- lack of affordable housing
- poor quality housing
- airbnbs/short term rentals
- studentification
- homelessness
Management strategies in housing for edinburgh
- more housing estates are being built by housing associations in different areas, eg small sites program
- Council houses are being upgraded, over half in past 5 years have gone through modernisation programmes
- stricter measures have been taken to deal with problematic landlords
- License scheme for people who let their property to short term tennants
- new policy for student housing estates
Problems of housing in rio
- Poor quality housing and services in favelas
- Overcrowding
- high levels of crime/gang activity
- landslides are common
- wealth divide
management strategies for housing in rio
- Self help schemes (training, materials, legal ownership) (success)
- Site and service schemes (Upgrading the favelas, making them safer, allowing people to rent) (semi-success, helps those with jobs)
- Project cingapura (clearing of favelas, replacing with tower blocks which have better services) (unsuccessful)
- Pacification (police force gangs out, allowing for other strategies to take place) (semi-successful, police semi corrupt)
- Non-government organisations (Charities building schools, finding jobs, etc.) (successful but rely on charity money)
Causes of malaria
- Areas of stagnant water (breeding grounds for mozzies)
- Temperatures between 15-40 degrees
- high rainfall and 60%+ humidity (allow water to support larvae)
- Human made water sources provide a place for mozzies to lay eggs
- rapid urban migration has led to a large blood source
- urban migration led to informal settlements often in marshy areas where mozzies are
- little investments made in mitigation allowing it to spread quickly
- higher demmand for food means more paddy fields, more stagnant water sources
impact of malaria
- high % of family incomes spent on treatment
- means less money available for food and education
- breeding season coincides with harvesting time so people may not be able to harvest crops
- less harvest = less food, leading to malnutrition
- less money spent on infrastructure
- high levels of absenteeism in school leads to lower literacy rates, = less skilled workforce
- future population affected by long term impacts may be unable to work
- foreign companies may not invest due to unreilable workforce
- tourists will avoid area reducing revenue
- causes a long term cycle of poverty
