rivers - physical Landscapes in UK

• Attrition


  Type of erosion where sharp, angular, large rocks are collided with other materials in the river which eventually makes it smaller, smoother and rounder.
• Hydraulic action


  Type of erosion, when the force of water and air squeezes into the cracks in the bed and bank of a river. This creates a high pressure which weakens the rock and causes it to eventually fall off over time.
• Abrasion


  Type of erosion, rocks which are carried by the river scrapes on the bed and the bank of the river. (sandpaper effect, smoothens the bed and bank)
• Fluvial processes


  a process which involves a river or water
• Solution (not visible)


  When moving water dissolves soluble rock like limestone, chalk and salt.
• Vertical erosion 


  A river which has more gravitational potential energy so erodes in a downwards manner. This creates steep sided V shaped valleys in upland areas.
• Lateral erosion


  A river which is lower down so has less gravitational potential energy so it erodes in a sideways manner. This creates wider, flat valleys with floodplains in lowland areas.
• Suspension 


  Type of transportation process, where fine load like silt and sand is suspended in the water and is moved by the river at normal conditions. It makes the river water look murky.
• Solution


  Type of transportation process, where load like salts and minerals are dissolved as a solute and is moved by the river at all types of conditions.
• Saltation


  Type of transportation process, where medium sized load bounces along the riverbed, usually during powerful and fast-moving river conditions.
• Traction


  Type of transportation process, where large sized load is rolled along the riverbed, usually during very powerful and fast-moving conditions like during a flood.
• Bedload


  Materials which transported along the riverbed, like saltation and traction.
• Dissolved load


  Material which is dissolved and carried in the river like solution.
• Suspended load


  Material which is suspended and carried by a river like suspension.
• Where does load come from?

  From valley sides.

  From the bed and banks of the river.
• Why does deposition occur?

  When a river is in low flow condition and has less energy, it deposits its load.
• General relationship between particle size and deposition rate.

  As particle size increases, the rate of deposition increases.
• Source


  The point at which a river begins.
• Tributary 


  A smaller channel joining into a larger channel.
• Watershed


  An imaginary line separating one drainage basin from another.
• Confluence


  A point which 2 or more river channels meet.
• Mouth


  The point where the river meets the sea.
• Label the drainage basin

  1. Source
  2. Confluence
  3. Watershed
  4. Tributary
  5. Mouth

  
• Surface runoff


  The movement of water over the surface of the ground into the river channel, quickest route.
• Throughflow 


  The movement of water through the soil into the river channel.
• Groundwater flow


  The movement of water through ground rock into the river channel, slowest route.
• Infiltration 


  the process of water moving through soil and rock layers
• Percolation


  filtration of water through soil and permeable rock.
• Permeable


  there are pores in the rock which allows water to be stored or move through it, for example chalk and sandstone is a permeable rock.
• Impermeable 


  water cannot move through impermeable material, for example granite, marble and slate.
• Groundwater


  water that has infiltrated the ground and is stored in pore and cracks in sediments and permeable rocks.
• Water table


  An underground boundary between soil surface and the area where groundwater saturates between sediment and cracks in rocks.
• Saturated zone


  a portion in the ground soil where all gaps are completely filled with water.
• Examples of storing water


  living organisms like plants, in the soil, frozen as icesheets or glaciers.
• Examples of output (fluvial)


  the sea via the mouth, a lake
• Examples of input into a drainage basin

  • precipitation like snow, rain, hail
  • frost and dew
• Upper course

  • more mountainous and steep terrain
  • higher altitude
  • contour lines are closer
  • vertical erosion is more dominant
  • more V shaped valleys
  • more narrow river channels (they occupy most of the valley floor)
• Middle course

  • hilly areas but is getting more flatter, and small floodplains.
• Lower course

  • flat terrain
  • lower altitude
  • contour lines are further apart
  • lateral erosion is more dominant
  • more floodplains and flat fields
  • lots of meanders
  • very wide rivers
• Discharge


  The amount of water passing through a certain point, measure in cm3