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Sunday, August 26

  1. page W-1 edited ... Attrition Solution Three videos on erosion by rivers - http://www.bbc.co.uk/learningzone/c…
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    Attrition
    Solution
    Three videos on erosion by rivers -
    http://www.bbc.co.uk/learningzone/clips/rivers-erosion-and-hydraulic-action/401.html
    http://www.bbc.co.uk/learningzone/clips/rivers-weathering-erosion-and-corrasion/400.html
    http://www.bbc.co.uk/learningzone/clips/the-river-conwy-erosion-and-deposition/3237.html

    Hydraulic action: this is the sheer force of the water hitting the bed and the banks. This is most effective when the water is moving fast and there is a lot of it.
    Abrasion: this occurs when the load the river is carrying repeatedly hits the river bed and the banks, causing some of the material to break off.
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    8:37 am
  2. page W-6 edited ... The discharge of a river shows much variation during a year and in the short term. It can fluc…
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    The discharge of a river shows much variation during a year and in the short term. It can fluctuate a lot in a matter of hours in response to periods of rain.
    Hydrological Cycle diagram
    A video on the hydrological cycle -
    http://www.bbc.co.uk/learningzone/clips/the-hydrological-cycle/406.html

    {Water Cycle.jpg}
    The storm hydrograph
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    8:36 am
  3. page W-3 edited ... In areas where lateral erosion and deposition become more important - meanders and oxbow lakes…
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    In areas where lateral erosion and deposition become more important - meanders and oxbow lakes develop
    In areas where deposition is the most significant process – floodplains and levees become a key aspect of the landscape.
    An overview of the River Tay - a river you will study -
    http://www.bbc.co.uk/learningzone/clips/river-tay-an-overview/4310.html
    Information on watersheds and drainage basins -
    http://www.bbc.co.uk/learningzone/clips/watersheds-and-drainage-basins/3238.html
    Video on the Upper Course of the River Tay -
    http://www.bbc.co.uk/learningzone/clips/river-tay-upper-course/4311.html
    Video on the Upper Course of the River Severn -
    http://www.bbc.co.uk/learningzone/clips/the-river-severn-upper-course/3076.html

    How is a waterfall formed?
    Very useful animation of waterfall formation:
    ...
    4. The drop gets steeper as the river erodes the soft rock beneath by processes such as abrasion and hydraulic action. A plunge pool forms at the base of the waterfall.
    5. This erosion gradually undercuts the hard rock and the plunge pool gets bigger due to further hydraulic action and abrasion. Eventually the hard cap rock is unsupported and collapses. The rocks that fall into the plunge pool will continue to enlarge it by abrasion as they are swirled around. A steep sided valley known as a gorge is left behind and as the process continues the waterfall gradually retreats upstream.
    Video on how waterfalls are formed -
    http://www.bbc.co.uk/learningzone/clips/waterfalls-geology-and-formation/4314.html
    Video on waterfalls, plunge pool and potholes -
    http://www.bbc.co.uk/learningzone/clips/waterfalls-plunge-pools-and-potholes/404.html

    How are gorges formed?
    A gorge is a steep-sided valley in the upper course of the river. It is usually v-shaped.
    http://www.cleo.net.uk/resources/displayframe.php?src=307/consultants_resources%2F_files%2Fgorge.swf
    Video on the formation of gorges -
    http://www.bbc.co.uk/learningzone/clips/waterfalls-and-gorges-erosion-and-deposition/3239.html

    What is the source?
    The source of the river is where the river originates from. It is in the upper course of the long profile.
    A video on the source of the River Severn -
    http://www.bbc.co.uk/learningzone/clips/the-source-of-the-river-thames/12571.html

    Key terms:
    Waterfall: the sudden and often vertical, drop of a river along it course
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    8:35 am
  4. page W-4 edited ... Oxbow lakes and meanders are found in the middle course of the river (long profile) and are fo…
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    Oxbow lakes and meanders are found in the middle course of the river (long profile) and are formed as a result if erosion and deposition.
    The formation of meanders leads eventually to the development of oxbow lakes
    Video showing the features of the middle course of the River Tay -
    http://www.bbc.co.uk/learningzone/clips/river-tay-middle-course/4312.html
    Video on meanders -
    http://www.bbc.co.uk/learningzone/clips/rivers-meanders/403.html
    Video on oxbow lakes -
    http://www.bbc.co.uk/learningzone/clips/rivers-oxbow-lakes/405.html

    Photograph of a river meander and an oxbow lake
    {RM.jpg} {oxbow.jpg}
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    8:28 am
  5. page W-5 edited ... Landforms resulting from deposition The formation of levees and floodplains are linked and in…
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    Landforms resulting from deposition
    The formation of levees and floodplains are linked and involve repeated flooding and the build-up of material during the period of flood. Under normal low conditions, the river is contained within its banks and so no sediment is available to form levees of the floodplain. However, during periods of high rainfall and discharge when the river has burst its banks, both of these features are formed.
    Video showing the lower course features of the River Tay -
    http://www.bbc.co.uk/learningzone/clips/river-tay-lower-course-and-estuary/4313.html
    Video showing the lower course features of the River Severn -
    http://www.bbc.co.uk/learningzone/clips/the-river-severn-lower-course-and-estuary/3077.html

    Floodplain and Levees – Formation diagram
    {Floodplain formatio diagram.jpg}
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    Key terms:
    Floodplain: the flat area adjacent to the river channel, especially in the lower part of the course. This is created as a natural area for water to spill onto when the river reaches the top of its banks
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    in height.
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    8:25 am
  6. page W-8 edited ... Interesting video link - http://www.bbc.co.uk/learningzone/clips/cities-on-flood-plains/11960…
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    Interesting video link -
    http://www.bbc.co.uk/learningzone/clips/cities-on-flood-plains/11960.html
    Flooding on the River Tay -
    http://www.bbc.co.uk/learningzone/clips/river-tay-floods-in-1993/4309.html

    Is flooding happening more often?
    The simple answer is yes but the cause is more difficult to ascertain. From the 1960s to the 1990s, big floods were pretty rare in the UK. However, serious floods now seem to be happening more often, as the table shows below:
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    8:24 am
  7. page W-9 edited ... The cost of protection Professor Samuels advises the government on managing rivers. He said ‘…
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    The cost of protection
    Professor Samuels advises the government on managing rivers. He said ‘It is technically possible to defend places like Cockermouth against extreme events, but only by building huge walls and embankments along the river, which would cost billions and alter the character of the town. For most people, that would be unacceptable as the floods.’
    Flood defence on the River Waal -
    http://www.bbc.co.uk/learningzone/clips/flood-defence-dyke-construction-on-the-river-waal/3253.html
    River management the River Mississippi -
    http://www.bbc.co.uk/learningzone/clips/river-management-the-mississippi/3078.html

    Hard Engineering
    Hard engineering involves building structures to defend places from floodwater.
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    Washlands
    These are parts of the floodplain that are allowed to flood
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    or nature
    reserves
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    8:21 am
  8. page W-8 edited ... http://www.shoothill.com/FloodMap/ - live flood warning map http://www.environment-agency.gov…
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    http://www.shoothill.com/FloodMap/ - live flood warning map
    http://www.environment-agency.gov.uk/
    Interesting video link -
    http://www.bbc.co.uk/learningzone/clips/cities-on-flood-plains/11960.html

    Is flooding happening more often?
    The simple answer is yes but the cause is more difficult to ascertain. From the 1960s to the 1990s, big floods were pretty rare in the UK. However, serious floods now seem to be happening more often, as the table shows below:
    (view changes)
    8:19 am
  9. page W-10 edited ... Temperatures could also rise due to global warming and so drought and water shortages could be…
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    Temperatures could also rise due to global warming and so drought and water shortages could become more common, especially in the South of the UK.
    {Water Transfer CS.jpg}
    Managing our water supplies
    Kielder Water fact file
    Kielder Water in Northumberland is the biggest man-made reservoir in northern Europe
    It is 12km long and up to 52 metres deep
    It cost £167 million to build and was completed in 1982
    It was built to meet an expected increase in water demand from north-east England – because of the rising population there and the expected growth of the steel and chemical industries. However, these industries haven’t grown as expected; in fact they’ve declined
    It is a water-transfer scheme (water is transferred from one area to another). The water from the reservoir is released into the Rivers Tyne, Derwent, Wear and Tees. This helps to maintain river flows when levels are low. Extra water can also be released for household and industrial use
    Kielder Water can provide up to 909 million litres of water a day (almost as much as all the other sources in the region added together
    Kielder Water: advantages and disadvantages
    Kielder Water has brought both benefits and disadvantages to the area.
    Advantages
    Disadvantages
    It has become a major tourist attraction. This has created jobs and benefited the local economy
    One an half million trees were cut down to build the reservoir
    The release of clean water into the River Tyne has encouraged salmon and sea trout to migrate upriver to breed
    A few families had to be moved and re-housed when the reservoir was built
    The north-east now has the most reliable water supply in England
    Forest Park, surrounding Kielder water, is harvested form timber and employs about 200 people
    If pollution occurs downstream, clean water can be released to dilute it and flush it out to sea
    The water is used to generate hydroelectric power at Kielder Dam
    The need for water transfer
    Kielder Water is a major water-transfer scheme. Before it was completed, the British government considered setting up a ‘national water grid’ (like the electricity grid) to transfer water from areas of the country with a surplus (e.g. Wales), to areas with a deficit (e.g. the south-east). This idea became popular in the 1970s, because of drought, but it didn’t happen in the end.
    By 2006, a national water grid was being talked about again – after some lengthy dry periods, and when the impacts of climate change became clearer. So far, it still hasn’t happened.
    The need for sustainable supplies
    The Environment Agency’s view about water is that: ‘We need to plan so that there are sustainable, reliable water supplies for people and businesses’. It is also concerned about protecting the environment. Some of the ways in which the Environment Agency thinks our water supplies can be more sustainable are listed below:
    Increase the use of rainwater harvesting, and grey water recycling for agriculture industry and commercial use
    Make new homes more water efficient
    Install water meters in all homes
    Reduce water leakage from pipes and reservoirs
    Consider the needs of the environment, wildlife, fisheries and recreation when allocating water resources
    Share water resources where there is a surplus
    Make appliances like washing machines and dishwashers more efficient
    Charge more for water to encourage people to use it in a sustainable way

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    8:14 am

Saturday, August 18

  1. page W-10 edited ... The UK is a crowded island, and we’re not evenly spread out. The population density ( the numb…
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    The UK is a crowded island, and we’re not evenly spread out. The population density ( the number of people per km squared) is highest in the south-east and in large cities like Birmingham and Manchester.
    UK Population density map
    {Pop density map.png}
    Rainfall (which is where our freshwater comes from) also doesn’t fall evenly across the UK – the west is wetter, and the south and east drier.
    UK Rainfall map
    {UK rainfall map.gif}
    The Environment Agency has described most of south-east England as suffering from ‘serious water stress’.
    WaterUK Water stress map
    {uk-water-stress-map.gif}

    Water stress happens when the amount of water available isn’t enough to meet the demand, or is of poor quality and differences in the distribution of rainfall and population can lead to areas of deficit and surplus.
    Areas of deficit do not have enough rainfall, or water
    ...
    By 2020, the demand for water could be about 5% higher than it is today. That’s a staggering 800 million litres of water a day. Not only will individual and household water use increase, but so will industrial use (e.g. in the building industry) and agricultural use (e.g. for irrigating crops).
    Temperatures could also rise due to global warming and so drought and water shortages could become more common, especially in the South of the UK.
    Scan in Hurst Pages 114-115
    Scan in Canavan Page 122
    {Water Transfer CS.jpg}
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    2:55 am

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