Drainage Basins

• what is a drainage basin?

  the area of land drained by a river and its tributaries
• what is a source ?


  where a river starts
• what is a tributary?

  a smaller river which joins the main river
• what is a river?

  water in a channel flowing towards the sea.
• what does the channel of a river have?

  river banks and a river bed
• what is a water shed?

  the edge of a drainage basin (ie where one drainage basin meets another)
• what is the mouth of the river?


  where the river enters the sea
• Name the input of the drainage basin?

  precipitation
• name the 3 outputs of the drainage basin as an open system?

  transpiration

  evaporation

  river runoff
• name the 5 stores of the drainage basin as an open system?

  • interception
  • vegetation storage
  • surface storage
  • soil storage
  • groundwater storage
  • channel storage
• Name the 8 flows of the drainage basin as an open system?

  • throughfall /stemflow
  • infiltration
  • percolation
  • groundwater flow
  • throughflow
  • flow
  • river flow
  • surface runoff
• What is infiltration?


  Water soaking into the soil
• What are infiltration rates influenced by?

  Soil type

  Soil structure

  How much water is already in the soil
• what is overland flow aka?


  runoff
• what is overland flow / runoff?

  Water flowing OVER THE LAND. It can flow over the WHOLE SURFACE or in LITTLE CHANNELS.
• Why does overland flow / runoff happen?


  Because rain is falling on the ground faster than infiltration occur
• What is throughfall?


  Water dripping from one leaf/plant part to another
• What is stemflow?


  Water running down a plant stem or a tree trunk
• What is throughflow?

  Water moving slowly downhill through the soil
• What is throughflow faster through?


  "pipes" - things like cracks in the soil or animal burrows
• what is Percolation?


  water seeping down through soil into the water table
• what is groundwater flow?


  Water flowing slowly below the water table through permeable rock

  Water flows slowly through most rocks, but rocks that are highly permeable with lots of joints can have faster groundwater flow (eg limestone
• what are joints?


  gaps that water can get through
• what is baseflow?

  Groundwater flow that feeds into rivers through river banks and river bed
• what is interflow?


  Water flowing downhill through permeable rock above the water table
• What is channel flow?


  The water flowing in the river or stream itself. this is also called the RIVER'S DISCHARGE
• What is INFILTRATION?


  FLOW
• What is OVERLAND FLOW?

  FLOW
• What is THROUGHFALL?


  FLOW
• What is STEMFLOW?

  FLOW
• What is THROUGHFLOW?

  FLOW
• What is PERCOLATION?

  FLOW
• What is GROUNDWATER FLOW?

  FLOW
• What is BASEFLOW?


  FLOW
• What is INTERFLOW\?

  FLOW
• What is CHANNEL FLOW?

  FLOW
• What are the outputs?


  evaporation, transpiration, evapotranspiration, river discharge/flow
• briefly describe outputs?


  water leaving the system
• what is evaporation?

  output
• What is transpiration?

  output