Flashcards
Geography (physical paper)
Cards in this deck (72)
- 11. Meanders are formed by?Erosion and deposition
- 22. What part of the rivers course are meanders found at?Middle and lower course
- 33. What speed is the current on the outside of the bend? (Fast or slow)Fast
- 44. Why is the current faster on the outside of the bend?Because the river channel is deeper and there's less friction to slow the water down
- 55. What speed is the current on the inside of the bend? (Fast or slow)Slow
- 66. Why is the current slower on the inside of the bend?Because the river channel is shallower and there's more friction to slow the water down
- 77. Where does the most erosion take place ( inner or outer bend) and what does this form?Outside of the bend which forms river cliffs
- 88. Where is the eroded material deposited (inner or outer bend) and what does it form?Inside of the slope which forms slip-off slopes
- 99. Ox-bow lakes are formed from ...Meanders
- 1010. How are on-bow lakes formed? First stage1. Erosion causes the outside bends to get closer until there's only a small bit of land left between the bends ( called the neck)
- 1111. How is an ox-bow lake formed? Second stage2. The river breaks through this land, usually during a flood and the river flows along the shortest course
- 1212. How is an ox-bow lake formed? Third stageDeposition eventually cuts off the meander forming an ox-bow lake
- 1313. How is a waterfall formed?Waterfalls are formed when a river flows over an area of hard rock followed by an area of soft rock
The softer rock erodes more that the hard rock creating a step in the river
As the water goes over the step it erodes more and more and a steep drop is formed which is called a waterfall - 1414. How is a gorge formed?First a water full is formed
The hard rock is eventually undercut by erosion and becomes unsupported and collapses. The collapsed rock ps are swirled around at the foot of the waterfall where they erode the soft rock by abrasion. This creates a deep plunge pool
Over time more undercutting causes more collapses. The water full will retreat, leaving behind a steep-sided waterfall - 1515. What is a flood plain?Wide floor on either side of a river which occasionally gets flooded
- 1616. How is a flood plain built up?When a river floods onto the floodplain, the water slows down and deposits the eroded material that it's transporting. This builds up the flood plain by making it higher
Meanders migrate across the flood plain making it wider
The deposition that happens on the slip-off slopes of meanders also builds up the flood plain - 1717. What is a levee?Natural embankments ( raised bits) along the edges of a river channel
- 1818. How are levees created?During a flood, eroded material is deposited over the whole flood plain. The heaviest material is deposited closest to the river channel, because it gets dropped first when the river slows down. Over time the deposited material builds up creating levees along the edges of the channel
- 1919. What is river discharge?Volume of water flowing in a river
- 2020. What is peak discharge?The highest discharge in the period of time you are looking at
- 2121. What is lag time?The delay between peak rainfall and peak discharge
- 2222. What is the rising limb?The increase in river discharge as rainwater flows into the river
- 2323. What is the falling limb?The decrease in river discharge as the river returns to its normal level
- 2424. Why does lag time happen?Because most rain water doesn't land directly in the river channel so there's a delay as rainwater gets to the channel.. It gets there by flowing quickly over land ( surface runoff) or by smoking into the ground ( infiltration) and flowing slowly underground
- 2525. What factors effect river discharge?Amount and type of rain
Temperature
Previous weather conditions
Rock type
Land use
Relief - 2626. How does amount and type of rainfall effect river discharge?Lots of rain and short heavy periods of rain means there's more runoff. Lag time is decreased, so discharge is increased
- 2727. How does temperature effect river discharge?Hot, dry conditions and cold, freezing conditions both result in hard ground which increases runoff. Lag time is decreased so discharge increases
- 2828. How do previous weather conditions effect river discharge?After a lot of rain, soil can become saturated ( it can't absorb any more water). More rainwater wound be able to infiltrate into the soil so runoff will increase. Lag time is decreased so discharge increases
- 2929. How does the rock type effect river discharge?Water infiltrates through pore spaces in permeable rock and flows along cracks in previous rocks so there isn't as much runoff. Lag time is increased so discharge decreases. Water can't infiltrate into impermeable rook so there is a lot of runoff. Lag time decreases so discharge increases
- 3030. How does land use effect river discharge?Urban areas have drainage systems and they're covered with impermeable materials like concrete which increases runoff. Lag time is decreased so discharge increases
- 3131. How does the relief effect river discharge?Lots of runoff occurs on steep slopes. Lag time is decreased so discharge increases
- 3232. What physical factors cause flooding?Prolonged rainfall
Heavy rain
Snowmelt
Relief - 3333. Why does prolonged rainfall cause flooding?Because after a long period of rain, the soil becomes saturated so any further rIn can't infiltrate which increases runoff into rivers. This increases discharge quickly, which can cause a flood
- 3434. Why does heavy rain cause flooding?Heavy rain means there's a lot of runoff so the discharge increases quickly which can cause a flood
- 3535. Why does snowmelt cause flooding?Because when a
lot of snow or ice melts it means that a lot of water goes into a river in a short space of time so discharge is increases quickly which can cause a flood - 3636. Why does relief cause flooding?If a river is in a steep-sided valley, water will reach the river channel much faster because water flows more quickly on steeper slopes. This increases discharge quickly which can cause a flood
- 3737. What human factors cause rivers to flood?Deforestation
Building construction - 3838. How does deforestation cause flooding?Trees intercept rainwater on their leaves, which then evaporates. Trees also take up wTer from the ground and store it. This means cutting down trees increases the volume of water that reaches the river channel, which increase dies charge and makes flooding more likely
- 3939. How does building constructions cause flooding?Buildings are often made from impermeable materials, e.g. Concrete, and they're surrounded by roads made from Tarmac ( also impermeable). Impermeable surfaces increase runoff and drains quickly take runoff to rivers. This increase discharge quickly which can cause a flood
- 4040. Flooding case study ( flood in a rich part and a poor part of the world)Rich part: Carlisle, England
Poor part: South Asia ( Bangladesh and India) - 4141. Dates of the two floodsEngland: 8th January, 2005
South Asia: July and August, 2007 - 4242. What were the rivers that caused these two floods?England: Eden
South Asia: Brahmaputra and Ganges - 4343. What were the causes of the flood in Carlisle?Heavy rainfall- 200 mm of rain fell in 36 hours. The continuous rainfall saturated the soil increasing runoff into the river Eden
Carlisle is a large urban area so impermeable materials like concrete increase runoff - 4444. What were the causes of the flood in South Asia?Heavy rainfall- 900 mm of rain fell in July. The continuous rainfall saturated the soil, increasing. Runoff into the rivers
Melting snow from glaciers in the Himalayan mountains increased discharge into the rivers - 4545. What were the primary effects of the Carlisle flood?3 deaths
Around 3000 people were made homeless
Rivers were polluted with rubbish and sewage - 4646. What were the primary effects of the South Asia flood?Over 2000 deaths
Around 25 million people were made homeless
Rivers were polluted with rubbish and sewage - 4747. What were the secondary effects of the Carlisle flood?Children lost out on education because schools had to close down due to them being flooded
Around 3000 jobs were at risk in business effect by flooding - 4848. What were the secondary causes of the South Asia flood?Children lost out on education - around 4000 schools were affected by the floods
Many farmers and factory owners became unemployed - 4949. What were the immediate response of the Carlisle flood?People were evacuated from areas that flooded
Temporary accommodation was set up for the people made homeless - 5050. What were the immediate response of the South Asia flood?Other governments and international charities distributed food, water and medical aid.
Rescue boats were sent to help people who were stranded - 5151. What were the long term response of the Carlisle flood?A flood defence has been set up to improve flood defences e.g. Build up banks the river Eden to prevent flooding
- 5252. What were the long term response of the South Asia flood?International charities have funded the rebuilding of homes and the agriculture and fishing industries
- 5353. Hard engineeringMan made structures built to control the flow of rivers and reduce flooding
- 5454. Soft engineeringSchemes set up using knowledge of a river and it's processes to reduce the effects of flooding
- 5555. Examples of hard engineeringDams and reservoirs
Channel straightening - 5656. Examples of soft engineeringFlood warnings
Preparation
Flood plain zoning
' do nothing' - 5757. What is a dam and reservoir?Dams are huge walls that are built across the rivers, usually in the upper course
A reservoir is an artificial lake the is formed behind the dam - 5858. What are the benefits and disadvantages of dams and reservoirs?Benefits:
Reservoirs store water, especially during periods of prolonged or heavy rain which reduces the risk of flooding
Disadvantages:
Dams are very expensive to build - 5959. What is channel straightening?Meanders are cut out by building artificial straight channels
- 6060. What are the benefits and disadvantages of channel straightening?Benefits:
Water moves out of the area more quickly because it doesn't travel as far which reduces the risk of flooding
Disadvantages:
There more erosion downstream because the waters flowing faster - 6161. What are the benefits and disadvantages of flood warnings?Benefits:
The impact of flooding is reduces as people have times to put sand bags out and evacuate
Disadvantages:
Warnings don't stop a flood from happening - 6262. What are the benefits and disadvantages of preparation?Benefits:
The impact of the flood is reduces
People know what to do when the flood happens
Disadvantages:
Preparation doesn't guarantee safety from a flood - 6363. What is flood plain zoning?Restrictions prevent building on parts of a flood plain that are likely to be affected by a flood
- 6464. What are the benefits and disadvantages of flood plain zoning?Benefits:
The impact of flooding is reduced as there aren't any houses or roads on parts that are likely to be flooded
Disadvantages:
It's no help in areas that have already been built on - 6565. What is ' do nothing'?No money is spent on new engineering methods or maintaining existing ones. Flooding is a natural process and people should accept the risks of living in an area that is likely to flood
- 6666. What are the benefits and disadvantages of ' do nothing'?Benefits:
Flooding makes farmland more fertile
Disadvantages:
The flood will probably cause a lot do damage as flooding is not being reduced - 6767. Uk reservoir case studyRutland water
- 6868. Where is Rutland water and when was it built?It is in the East Midlands and was built in the 1970's
- 6969. What are the economic impacts of Rutland water?The reservoir boosts the local economy as it is a popular tourist attraction because if the wildlife and recreational facilities
Around 6km squared of land was flooded to create the reservoir which included farmland so farmers lost their livelihoods - 7070. What are the social impacts of Rutland water?Lots of recreational activities take place on and around the reservoir, e.g. Sailing, windsurfing, bird watching and cycling
Many jobs have been created I build and maintain the reservoir and to run the nature reserve and recreational activities
Two villages were demolished to make way for the reservoir - 7171. What are the environmental impacts of Rutland water?Hundreds of species of birds live around the reservoir
A large area of land was flooded to create the reservoir which destroyed some habitats - 7272. How is Rutland water managed sustainably?People can only take out as much water as is replaced by the rivers that supply it so that the supply will stay the same for the future
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- Flashcards on Geography (physical paper), created by darceyinman on 15/05/2015.
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- darceyinman · May 2015
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- Feb 19, 2016
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