Hydrosphere Flashcards
What are the three uses of water and how much does each use?
Agriculture- 70%
Industry- 22%
Domestic uses- 8%
How is water used in agriculture?
Irrigation
How is water used in industry?
Cooling, heating, washing and solvent
How is water used in domestic use?
Flushing toilets, washing clothes, dishes and hygiene
Why has the global demand for water increased?
Increasing population
Increase per-capita use with affluence
Increased irrigation of farmland
Industrialisation
What are the different reservoirs in the hydrological cycle?
Ocean, land ice, groundwater, lakes and rivers, soil moisture, atmosphere and living organisms
What is the quantity of water and resident time of oceans?
97%
Up to 4000 years
What is the quantity of water in land ice?
2%
What is the quantity of water in groundwater?
0.7%
What is the quantity of water in lakes and rivers?
0.01%
What is the quantity of water in soil moisture?
0.005%
What is the quantity of water in the atmosphere?
0.001%
What is the quantity of water in living organisms?
0.00004%
How are residence times calculated?
Volume of water in the reservoir divided by mean transfer rate
What are some human impacts on the hydrological cycle?
Deforestation, agriculture, urban development and global climate change
What is river channel discharge?
The total volume of water flowing through a channel at any given point
What human activities may affect precipitation?
GCC, abstract use, deforestation and afforestation
What human activities affect interception?
Vegetation- deforestation and afforestation
What human activities affect infiltration?
GCC, amount of soil
What human activities affect percolation?
Types of rock, GCC, heavy machinery
What human activities affect groundwater flow?
GCC, distribution of rain
What human activities affect runoff?
The surface (concrete)
What human activities affect evaporation?
GCC
What human activities affect transpiration?
GCC, deforestation and afforestation
What human activities affect river channel discharge?
Dams, GCC
What is the water table?
The boundary between ground saturated and unsaturated with water
What is a well?
A drilled hole to access an aquifer and pump/pipe water out, unwanted particles are filtered out (unconfined aquifer)
What is an Artisan well?
Doesn’t require a pump as the pressure in the confined aquifer forces the water out to the surface
What is porosity?
The volume of space available in a geological structure
What are 3 porous rocks?
Sandstone, shale and limestone
What is permeability?
The time taken for fluid to pass through a geological structure
What are 3 permeable rocks?
Sandstone, limestone and chalk
What geological structures may be present in order to create an aquifer?
Impermeable rock underneath
Explain the trends in domestic water use in the UK?
Increased overall- population and affluence
Increase SE England- population density for work
Increased S and SW- population migration for retirement
Explain the trend in agricultural water use in the UK?
Temperature rise means more irrigation is needed
Explain the trends in industrial use of water in the UK?
Decrease- more service industries
Decrease in NW England and S Wales- decline in heavy industry
What are the environmental effects of reservoirs?
Habitat change, wildlife barriers, river regime downstream of dams, sedimentation, microclimates
How do reservoirs affect habitat?
They destroy the previous, however they create wetlands, which are uncommon habitats and may be more valuable than the previous ones
How do reservoirs create wildlife barriers?
Barriers to wildlife that migrate along the rivers such as salmon and sturgeon, this is important for recolonisation of vacant areas
How do reservoirs affect river regime?
Regulate it by holding back in times of surplus and releasing when theres low amounts
What do changes in river flow affect?
Change river erosion and sedimentation and the development of meanders
Why are periods of low river flow important?
Some species, such as river turtles, need this time to lay their eggs on sandbanks
Why are periods of rapid river flow important?
Wash away sediments from gravel river beds for trout and salmon to lay their eggs
How is sedimentation in rivers affected by reservoirs?
Settle in the reservoir and not be carried downstream, they may have been important in fertilising flood plains downstream, counteracting erosion and building coastlines
How are microclimates affect by reservoirs?
Th large body of water may change the local climate due to high heat capacity of water temperature fluctuations are reduced, higher wind speeds, greater evaporation
How does most aquifer recharge occur?
Precipitation
When were some confined aquifers last recharged?
The previous ice age 10-20,000 years ago when the global climate was wetter
What are the dangers of ancient aquifer water in agriculture?
Often saline and can cause soil salinisation as irrigation water evaporates, leaving the salt behind, causing dehydration in plants
What are the dangers in over-exploitation of aquifers?
Changes in surface hydrology, ecological impacts, salt water incursion, subsidence, reduced supplies
How might ecology be affect by over-exploited aquifers?
Lowering the water table may kill plants and wetlands draining can kill aquatic or semi-aquatic plants
How might surface hydrology be affected by over-exploited aquifers?
Over-exploitation of groundwater will no longer be able to feed rivers, lakes and marshes
How might salt water incursion occur from over-exploitation of aquifers?
In coastal areas as the water table is lowered below sea level, it will cause the water flow sideways, this salt water makes the aquifer water unsuitable for irrigation as osmotic dehydration may occur
How might subsidence be affected by over-exploitation of aquifers?
The removal of water removes support for the geological structure which will now compact due to the material above, causing serious damage to buildings and pipelines
How might reduction in supplies be problematic due to over-exploitation of aquifers?
Unsustainable use means activities that have relied on it for hundreds of years may have to suddenly stop