drainage basins

Drainage basins

• An area of land drained by a river

• drainage basins are open systems:
  • there are inputs of water to drainage basins
  • water flows through them and is stored in them
  • there are outputs of water from drainage basins 

inputs - precipitation 

flows-surface runoff --- channel flow --- infiltration ---- throughflow --- groundwater flow ---   percolation 

stores- channel storage --- groundwater storage --- interception storage --- surface storage 

outputs- evaporation --- transpiration --- river flow into the sea 

FEATURES OF A DRAINAGE BASIN 

--> they are seperated by a boundary called a watershed 

--> they are ridges of highland water fallinh either side of these ridges will go into different drainage basins

key features of a drainage basin:

• a tribituary is a smaller river that joins a main river
• the source is where the river starts, usually in a upland area e.g. a mountain
• a counfluence is a point where two rivers join
• the mouth…