GCSE GEOGRAPHY

• A drainage basin is the area of land drained by a river and its tributaries
• The water cycle, also known as the hydrological cycle, is the system where water is constantly moving above, on, or below the earth’s surface and changing state
• Key terms in the water cycle:

  • Infiltration: downward movement of water from the surface into the soil
  • Surface runoff: water flows across the earth's surface becoming a stream, tributary, or river
  • Precipitation: rain, hail, sleet, or snow input to the drainage basin system
  • Evapotranspiration: water vapor evaporated from trees and vegetation back into the atmosphere
  • Throughflow: water flows downhill within the soil
  • Groundwater flow: water flowing slowly through rocks towards the sea
  • Percolation: downward movement of water from the soil into the rock beneath
• A drainage basin is the area of land drained by a river and its tributaries
• When a droplet of water falls onto the land as precipitation, gravity ensures the water is 'pulled' downhill to return to the sea
• Inputs in the drainage basin system include precipitation, while stores involve interception, soil moisture, surface storage, and groundwater
• Transfers in the drainage basin system include surface run-off, infiltration, percolation, through-flow, and groundwater flow
• Outputs in the drainage basin system involve river discharge and evapotranspiration
• A drainage basin is the area of land drained by a river and its tributaries
• When a droplet of water falls onto the land (as precipitation), gravity will make sure that the water is ‘pulled’ downhill to return to the sea
• Key characteristics of the drainage basin:

  • Drainage basin: the area of land drained by a river
  • Catchment area: the area within the drainage basin
  • Watershed: the edge of highland surrounding a drainage basin which marks the boundary between two drainage basins
  • Source: the beginning or start of a river
  • Confluence: the point at which two rivers or streams join
  • Tributary: a stream or smaller river which joins a larger stream or river
  • Mouth: the point where the river comes to the end, usually when entering a sea
• A drainage basin is the area of land drained by a river and its tributaries
• When a droplet of water falls onto the land (as precipitation), gravity ensures the water is 'pulled' downhill to return to the sea
• A river changes shape as it flows from its source to its mouth, with distinctive characteristics in the upper, middle, and lower courses
• Near the source of a river, it flows over steep slopes with uneven surfaces, often forming waterfalls and rapids
• Vertical erosion occurs as the river cuts down towards the river bed, carving out steep-sided V-shaped valleys
• As the river moves towards the mouth, the gradient of the slope becomes less steep, and the depth and width of the river increase
• The load of a river changes as it is transported and eroded along the river's profile, with stones becoming smaller and more rounded
• The discharge of a river increases as it approaches the sea, usually calculated as the cross-sectional area (depth x width) multiplied by the velocity of the water
• River processes shape the land in different ways as the river moves from its source to its mouth
• Erosion


  1. Erosion involves the wearing away of rock and soil found along the river bed and banks

  2. Erosion takes place when parts of the river bank or river bed are worn away and removed from the landscape

  3. Erosion also involves the breaking down of the rock particles being carried downstream by the river
• Types of river erosion

  • Hydraulic action
  • Abrasion/Corrasion
  • Attrition
  • Solution/Corrosion
• Hydraulic action


  The force of the river against the banks can cause air to be trapped in cracks and crevices, weakening the banks and gradually wearing them away
• Abrasion/Corrasion


  The force of the water in the river carrying stones and other materials grinds the bedload like a piece of sandpaper
• Attrition


  Rocks being carried by the river smash together and break into smaller, smoother, and rounder particles
• Solution/Corrosion

  Soluble particles are dissolved by weak acids in the water
• Types of river landforms

  • Upper course
  • Middle course
  • Lower course
• Upper course


  The highest section of a river located in the mountains
• Lower course

  The final section of a river located on flat land
• River moving from upper course to lower course

  Features in the river will change
• River features in upper course

  1. Waterfalls

  2. Gorges
• Waterfall


  • A vertical cliff of water where the water flows over a layer of hard rock on top of a layer of softer rock. The softer rock is eroded away causing the cliff edge to gradually move backwards
• Waterfall formation

  The softer rock is eroded away causing the cliff edge to gradually move backwards
• Power of waves


  Significant factor in coastal processes
• Types of waves


  • Constructive
  • Destructive
• How waves are created

  Waves are created due to the transfer of energy through seawater as the wind blows across the surface of the sea
• Destructive waves


  • Help to erode a beach
  • Have a lot of energy, are steep and close together with at least 15 waves per minute
• Constructive waves


  • Help to build up a beach
  • Are flat, gentle and low and there are only a few waves per minute
• With a constructive wave

  The swash is stronger than the backwash
• With a destructive wave


  The backwash is stronger than the swash