river

• Precipitation


  When water vapour condenses on and falls towards the surface of the earth
• Interception by vegetation

  • Water gets caught (blocked) by trees and plants and stored on the leaves
  • Interception is greater with more leaves
• Surface storage


  Water stored in puddles
• Soil moisture storage


  Water stored in the soil
• Groundwater store


  Water stored at depth in rocks
• Surface runoff


  • The fastest transfer of water movement
  • Occurs when the water table rises during wet weather
  • Occurs when the soil or surface is impermeable and does not allow water to pass through
  • Occurs when the soil has become saturated and there is no space left for more water to enter
• Infiltration


  The downward movement of water from the surface of the soil through tiny pores
• Throughflow


  The movement of water sideways through the soil and it is likely to form, eventually, a spring on the valley side
• Percolation


  The movement of water downwards through the rock from the soil
• Groundwater flow

  • The slowest form of water transfer
  • Water flows very slowly from the rock back into the river
• River discharge


  When the water is carried through the river and back into the sea
• Evapotranspiration


  Water turning into water vapour in the air, and water turned into water vapour by plants through their leaves
• Drainage Basin Key Terms


  • main
  • river
  • channel
• Drainage Basin


  The area of land drained by a river and its tributaries
• Watershed


  A ridge of high land that separates one drainage basin from neighbouring drainage basins
• Source


  The point where a river starts, usually on high land
• Tributary


  A small stream which joins onto a main river
• Confluence


  The point where two rivers/tributaries meet and join
• River Channel


  The main body of water flowing downhill
• Mouth


  The end of a river, usually where it enters the sea, but sometimes where it enters a lake
• Height (m above sea level)

  • 400 Source
  • 300-200 Upper Course
  • 100-0 Lower Course