The drainage basin system Flashcards
What is a drainage basin? (catchment)
The land area drained by a river and the rivers tributaries
What is the watershed?
The higher land dividing the basins (The basin boundary)
Where is Earths largest drainage basin?
The Amazon Basin in South America, drained by the Amazon River (7.5m km^2)
What is North America’s largest basin?
The Mississippi Basin that takes up almost 50% of the US!
What sort of systems are drainage basins?
Open systems where the quantity of water changes as water arrives from the atmosphere and leaves to the atmosphere or the ocean
What do drainage basins operate within?
The closed system of the GHC
What are examples of inputs of a drainage basin?
Rain, mist or snow
What are examples of outputs of a drainage basin?
Evaporation, transpiration or river flow into the ocean/another river
What are examples of flow within a drainage basin?
Water flowing over the ground surface, water flowing in the river channel and subsurface flow (water flowing downhill through the soil)
What are examples of stores within a drainage basin?
Water stored in soil, water stored in permeable bedrock (aquifers) and water stored in the river channel
What is the only natural input to the drainage basin system?
Precipitation
When does precipitation occur?
When moist, warm air rises then cools and its water vapour condenses then clouds form
What are the different types of rainfall?
Convectional, Frontal and Relief
