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• The long profile of a river is a line representing the course of the river from its source to it’s mouth and the changes in height along its course.
• A cross profile is a line that represents what it would be like to walk from one side of a valley, across the channel and up the other side.
• A valley is a low area of land between hills or mountains.
• The channel is the bed that the river flows within. 
• Erosion: When land is worn away by the action of the river. 
• Transportation: When the river moves its load from one place to another – downstream
• Deposition: When the river drops its load. 
• Load: Material carried by the river. 
• erosion has 4 processes:

  hydraulic action

  abrasion

  attrition

  solution
• Hydraulic Action – The force of the river against the banks can cause air to be trapped in cracks and crevices. The pressure weakens the banks and gradually wears it away.
• Attrition – When the stones and boulders carried by the river knock against each other and over time are weakened, causing bits to break and creating smoother, smaller and rounder. 
• Abrasion – This is when rocks and pebbles carried by the river hits the bed and banks, causing bits to break off. 
• Solution – River water contains weak acids. The acids cause some types of rock (chalk and limestone) in the banks to dissolve, and they are carried away by the river (transported). 
• upper course features:

  • water falls
  • gorges
  • rapids
• middle course features:

  • meanders
  • ox-bow lakes
  • floodpains
• lower course features:

  • floodplains
  • deltas
  • estuaries
• upper course channel - narrow and shallow
• middle course channel - wider and deeper channel
• lower course channel - widest and deepest channel
• vertical erosion - river cutting downwards into its bed
• lateral erosion - river cutting sideways into the banks
• transportation:

  supervision

  solution

  traction

  saltation
• suspension - the water carries small particles or material, process is present throughout but more common towards mouth
• solution - material is dissolved within the water and carried along by it. Primarily this occurs in the middle or lower course
• traction - the largest rocks in the river are slowly rolled along the bottom of the river by the force of the water, primarily n the upper course
• saltation - smaller rock are bounced along the river bed, this occurs in the upper and middle course
• erosion

  A) hydraulic action

  B) solution

  C) abrasion

  D) attrition

  
• transportation

  A) suspension

  B) solution

  C) saltation

  D) traction

  
• reasons for deposition:

  • speed of a river reduces
  • volume of water in the river reduces
  • the water is shallower
  • the river reaches its mouth
• process of waterfall forming :

  1. water flows over hard rock layered over soft rock, overtime they are eroded
  2. the soft rock erodes faster than hard rock causes undercutting
  3. overtime a plunge pool is created where erosion intensifies
  4. undercutting continues and hard rock forms an overhang
  5. eventually collapses into the plunge pool
  6. process repeats
• waterfall/plunge pool

  A) hard rock

  B) fallen rocks

  C) plunge pool

  D) overhang

  E) waterfall retreats

  
• meander

  A) slip off slope

  B) slower current

  C) fast current

  D) sand and shingle deposit

  E) bank undercut

  F) river cliff

  
• process of meander forming:

  1. meander starts to from because something on the bed of the river pushed the water to one side
  2. when the water is pushed to one side, lateral erosion of the bank starts to occur
  3. as the water is pushed around the bend, most of the water is pushed to the outside causing increased lateral erosion
  4. more material is eroded from the outside bend and deposited on inside bend
  5. causes a river cliff to form on the outside bend and lateral erosion deposits causes a slip off slope to form
• process of an oxbow lake forming:

  1. as erosion and deposition continue the neck of the meander pushes together, forming a narrower neck
  2. eventually the neck of the land is eroded through and the river will cut through it to create a new shorter course
  3. the river now flows straight and use the bend of the meander
  4. deposition now cuts off the old meander forming an oxbow lake
• physical factors affecting flood risk:

  precipitation

  geology

  relief
• human factors affecting flood risk :

  land use
• Factors affecting flood risk - precipitation:

  • torrential rain is heavy rain over a short period of time, so the water doesn't have time to soak in so overflows
  • prolonged rainfall isnt necessarily heavy but it mans that it rains for a long time, this means the soil is saturated so water runs over the surface
• factors affecting flood risk - geology:

  the rock type of the area, if it is mainly impermeable rock, then water cannot infiltrate through it so it runs over the surface
• factors affecting flood risk: relief

  f the land is steep then the water will have little time to soak in so water will run off to the channel, meaning a flood is more likely downstream due to increase in water
• factors affecting flood risk - land use:

  the way humans use the land has a large imact on the likelihood of flooding in the area. Id=f an area around a river is urbanized and very impermeable, then it is more likely to flood as the water will have no where to go