The Hydrological Cycle Flashcards
What is residence time?
How long a particular water molecule spends in a particular store.
E.g. long residents time may be ice and short residence time may be living things
What is transfer rate?
The amount of time it takes a water molecule to be transferred from one store to another.
How do you work out residence time?
Volume (km^3) / transfer rate (km^3 year^-1)
Name all the water reserves
Oceans
Land ice
Groundwater
Lakes and rivers
Soil moisture
Atmosphere
Living organisms
What percentage of the hydrosphere is oceans?
97%
What percentage of the hydrosphere is land ice?
2%
What percentage of the hydrosphere is groundwater?
0.7%
What percentage of the hydrosphere is lakes and rivers?
0.01%
What percentage of the hydrosphere is soil moisture?
0.005%
What percentage of the hydrosphere is the atmosphere?
0.001%
What percentage of the hydrosphere is living organisms?
0.00004%
Which reservoir has the longest water residence time?
Groundwater
Which reservoir has the shortest water residence time?
Living organisms
What is evaporation?
The process by which a liquid turns into a gas
What is precipitation?
Any liquid or frozen water that forms in the atmosphere and falls to the earth.
What is transpiration?
A process that involves the loss of water vapour through the stomata of plants
What is infiltration?
The flow of water from above ground into the subsurface.
What is interception?
The part of the rainfall that is intercepted by the Earths surface and which subsequently evaporates.
What is percolation?
The movement of water through the soil itself
What is runoff?
Occurs when there is more water than land can absorb
What is surface flow?
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What is groundwater flow?
Gravity and pressure move water downwards and sideways through spaces between rocks. Eventually merges back to land surface.
What is abstraction?
The process of taking or extracting water from a natural source (rivers, lakes, groundwater aquifers, etc.) for various uses, from drinking to irrigation, treatment, and industrial applications.
How does building dams affect the water cycle?
Holds water, reducing percolation and infiltration
Decreased groundwater and increased surface water
How does urbanisation affect the water cycle?
Increased interception of water
Increased surface flow and runoff due to impermeable surfaces such as concrete and tarmac
How does deforestation affect the water cycle?
Increased surface flow and runoff due to decreased interception
Decreased transpiration rate
How does combustion of fossil fuels affect the water cycle?
Increased greenhouse gases leads to increased temperatures and water in the ocean
This leads to increased evaporation and increased precipitation
How does food production (agriculture) affect the water cycle?
Abstraction of water from natural stores to be used in agriculture
How does mining affect the water cycle?
If mining is below natural water table, you must decrease ground water by pumping it into rivers and other bodies of water
How does consumption affect the water cycle?
Collect water in reservoirs
Domestic uses
Drinking
How do canals affect the water cycle?
Suez Canal - man made, changed transport of goods, sea water
Block in order to increase and decrease water levels
How does afforestation affect the water cycle?
Decreases surface flow and runoff due to increased interception
Increased transpiration
How do aquifers affect the water cycle?
Abstraction of water
What are the major factors that may cause demand for water to change?
Change in industry over time
Increase in population
Change in affluence
Increased food production/agriculture
What is the most water used for in the UK?
Energy industry (eg used for cooling)
Define water footprint
An environmental indicator that measures the volume of fresh water (in litres or cubic metres) used throughout the entire production chain of a consumer item or service.
Name and describe the exploitation of a river
The River Nile
Exploited by Egypt downstream
Other countries upstream begin to use it for economic gains
Supports agriculture and fishing
Sediment at bottom polluted with heavy metals
Many people rely on it
Flow has dropped
Lake Victoria which supplies the Nile may dry up
Dam built
What is a reservoir and why do we build them?
A reservoir is an artificial lake where water is stored.
Reservoir water can be used to supply water to our homes and factories. Reservoirs are designed to store the rain that falls during the wetter parts of the year, so that there is a continuous supply of water for the drier periods.
Also a critical part of flood risk management
What are the advantages of reservoirs?
Flood management
New jobs
Reliable
Cheap water
New habitats