Temporal variations in river discharge Flashcards
What is a river regime?
The annual variation in the discharge or flow of a river
What is a simple regime?
One peak discharge
What is a complex regime?
Multiple peak discharges
What are the physical factors influencing river regimes?
Climate
Vegetation
Soil
Geology
Explain the climate factors influencing river regimes
Annual precipitation pattern
Seasonal variations in temperature
Evaporation rates
What are the human factors influencing river regimes?
Land use
Irrigation and use of water
Dam construction, creating reservoirs to store water and even out the flow throughout the year
All human and physical factors influence what in a river regime?
The volume of water reaching the river
How quickly the water reaches the river (via flows and stores) from the drainage basin
What do storm hydrographs show?
How the discharge in a river changes after one storm event
What can hydrographs also be used to show?
How the discharge in a river channel responds to inputs over a year (annually), or even longer periods of time, this is the river regime
The seasonal variations in hydrographs tend to reflect what?
Reflect the climate, especially the amount and type of precipitation
What are other major controls on the shape of the river’s regime?
Rock permeability
Basin size
Relief (e.g. slope angles)
Amongst other things
The non-climatic factors are more significant trying to explain differences between rivers which have very similar climates and sizes for what kind of river basin?
Small river basisns
Give examples of large river basins
Mississippi
Amazon
Euphrates
Brahmaputra
Ganges
What helps us explain the river regimes and hydrograph shapes for larger drainage basins (Catchment areas)?
Understanding world climate zones i.e. the precipitation and temperature characteristics
What is meant by the term summer baseflow?
Less water in ground
