Water Cycle 2 Flashcards
Give 4 possible ways human can affect the water cycle within a drainage basin (local scale)
Throughout the world there have been major changes to the water cycle from climate change and land use change
Deforestation means there is less interception so overland flow increases. Also decreases evapotranspiration so maybe less precipitation from conventional rainfall
Land use change may increase flood risk (urbanisation, deforestation)
Humans modifying the flows of rivers by abstraction of water (dams). When water is released back it may be of different tempatue/quality
Give 3 types of system
Open
Closed
Isolated
What is an open system
Moist environment systems are open and there are inputs and outputs of both energy + matter
What is a closed system
Inputs and output of energy but not matter (planet earth)
What is an isolated system
No input or output of energy or matter (universe)
Some claim this idea is not applicable to geography
What is dynamic equilibrium
When opposing inputs and outputs in the system are balanced
Give an example of a cause on the water cycle for disrupting the dynamic equilibrium of a system
Prolonged heavy rainfall causes an increase in the discharge and velocity of a river, increasing rate of erosion
How do Chroley and Hagget describe systems
A simplified structuring fo reality which presents significant features/relationships in a. generalised form, allowing the fundamental aspects of reality to appear
An open system tends to…….itself by modifying the interrelationships between different elements fo the system so….and output flows………each other out
Adjust
Inputs
Balance
What is feedback
Occurs when one element of a system changes because of an outside influence, upsetting the dynamic equilibrium
What is negative feedback
When a system acts by lessening the effects of the original change and ultimately reverses it
What is positive feedback
When a change causes a further/snowball effe t, continuing or accelerating the original change
What is the dew point temperature
The temperature bellow which droplets begin to condense and dew forms (air saturated)
How does precipitation vary worldwide
Influenced by general circulation of the atmosphere, proximity to large bodies of water and topography
Give the 4 global stores of water, their percentage of total water and residence time
Hydrosphere (97%) 3,600 years
Lithosphere (1.7%) 10,000 years
Cryosphere (1.7%) 15,000 years
Atmosphere (0.001%) 10 days
Why are residence times longer in larger stores
Big stores - vast majority fo water molecules are very far from he boundary and thus takes a long time to escape
Are the cryosphere and hydrosphere in a state of equilibrium
No
Crysophere - more out than in
Hydrosphere - More in than out (Global warming) (opposite in ice age - temperature dependent)
Lithosphere and atmosphere tend not to change a great deal