rivers

• Waterfalls and Gorges are Found in the Upper Course of a River
• River Clyde

  • About 160 km long
  • Source is in the Southern Liplands of Scotland, and it flows north-weg through Motherwell and Glasgow
  • Mouth is an estuary on the west coast of Scotland
• River Clyde's estuary

  • About 34 km west of Glasgow
  • About 3 km wide
  • Shows the mudflats, which are exposed at low tide
• River Clyde's flood plain

  • Glasgow is built on it
  • Land is about 5 above sea level either side of the river
• River Clyde


  • Has a gorge formed by waterfalls
  • Meanders between Motherwell and Glasgow
  • Has interlocking spurs between 300 and 500 m high at Crawford
  • Has the Falls of Clyde, with the highest fall Cora Linn at 27 m high
  • Has a meander in the New Lanark area that may form an ox-bow lake over time
• Meanders are Formed by Erosion and Deposition

  1. Faster current on outside of bend (due to less friction) causes more erosion, forming river cliffs

  2. Slower current on inside of bend (due to more friction) causes deposition, forming slip-off slopes
• Interlocking spurs


  • Form in the upper course of a river where erosion is mainly vertical, creating steep-sided, V-shaped valleys
  • Rivers have to wind around the high hillsides that stick out into their paths on either side
• Peak discharge


  The highest discharge in the period of time you're looking at
• Lag time


  The delay between peak rainfall and peak discharge
• Rising limb


  The increase in river discharge as rainwater flows into the river
• Falling limb


  The decrease in river discharge as the river returns to its normal level
• Flooding occurs when a river's level rises so much that it spills over its banks
• Factors that shorten the lag time, so the peak discharge is higher and flooding is more likely to occur

  • Heavy Rainfall
  • Prolonged Rainfall
  • Geology (rock type)
  • Relief (changes in land height)
• Heavy rainfall


  Water arrives too quickly to infiltrate, so there's a lot of surface runoff, which increases discharge
• Prolonged rainfall


  Can saturate the soil, so any further rainfall can't infiltrate, increasing runoff into river channels
• Geology (rock type)


  Clay soils and some rocks, e.g. granite and shale, are impermeable (i.e. they don't allow infiltration), so runoff is increased
• Relief (changes in land height)

  If a river is in a steep-sided valley, water will reach the river channel quicker because it can flow faster down the steep slopes, this rapidly increases discharge
• Ways changing land use can increase flood risk

  • Buildings are often made from impermeable materials (e.g. concrete) and surrounded by roads made from impermeable surfaces (e.g. tarmac), increasing surface runoff. Man-made drains then quickly transport runoff to rivers, increasing discharge.
  • Cutting down trees increases the volume of water that enters the river channel
• Waterfalls and Gorges formation

  1. Waterfall forms where a river flows over an area of hard rock followed by an area of softer rock

  2. Softer rock is eroded more than the hard rock, creating a 'step' in the river

  3. Water flows over the step and erodes more of the softer rock

  4. A steep drop is eventually created, which is called a waterfall

  5. Hard rock is eventually undercut by erosion and collapses

  6. Collapsed rocks are swirled around at the foot of the waterfall where they erode the softer rock by abrasion

  7. Over time, more undercutting causes more collapses and the waterfall retreats, leaving behind a steep-sided gorge
• Meanders formation

  1. Rivers develop large bends called meanders in their middle and lower course

  2. The current is faster on the outside of the bend because the channel is deeper, resulting in more erosion

  3. The current is slower on the inside of the bend because the channel is shallower, resulting in deposition

  4. Eroded material is deposited on the inside of the bend
• Oxford Flood Alleviation Scheme

  1. Planning began in 2014

  2. Spans 5 km

  3. Includes both hard and soft engineering strategies

  4. Diverts water away from more densely populated areas

  5. Protects the city centre
• Flood Management Scheme


  • Reusing excavated material to build new flood walls and embankments to protect areas that remain at risk
  • Planting 20,000 trees and shrubs around the excavated area to slow runoff and decrease peak discharge
  • Increasing water storage in the floodplain and in an existing bypass channel southwest of Oxford - 400,000 m3 of earth will be dug up to increase capacity