Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Geography > The water cycle > Flashcards

The water cycle Flashcards

(59 cards)

Start Studying
1
Q

What is the global hydrological cycle?

A

A closed system where water is continually cycled through the stores, none is lost or gained from other systems, and is driven by solar energy.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is the global water budget?

A

Annual balance of water cycles and store of water flows.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a drainage basin?

A

An area of land drained by a river and its tributaries and separated from neighbouring drainage basins by a high land ridge called a watershed. It is an open system.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What factors affect drainage basin input?

A

Precipitation is the major input, with the highest being in the tropics. This is also influenced by continentality (distance from the sea).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What factors affect drainage basin flows?

A
  • Interception
  • Infiltration and throughflow
  • Direct runoff
  • Percolation and groundwater flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What is interception?

A

Interception - vegetation blocking water from hitting the ground.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is infiltration and throughflow?

A

Infiltration - Movement of water vertically through pores in the soil.
Throughflow - The downslope movement of water through the soil towards a river or stream.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What is direct runoff?

A

Water flowing over the surface of the ground. This can be saturated overland flow (water table reaches the surface) or infiltration-excess overland flow (rate of infiltration can’t keep up with rainfall intensity).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What is percolation and groundwater flow?

A

Percolation - Infiltrating water reaches porous bedrock and is stored in these pores when there is a layer if impermeable rock underneath.
Groundwater flow -The movement laterally of water at the water table.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What is an aquifer?

A

A porous rock that stores water.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What factors affect drainage basin output?

A
  • Evaporation and transpiration.
  • Channel flow
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is evaporation and transpiration?

A

Evaporation - water transformed to water vapor.
Transpiration - water taken in by plants and evaporated through the stomata.
Evapotranspiration - the total of these.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is channel flow?

A

Water that has collected to flow in a rivulet stream or river - another output of water from a drainage basin. Discharge = volume of water passing by a specific point of measurement in a specific amount of time.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What human activities disrupt the drainage basin?

A
  • Cloud seeding
  • Urbanisation
  • Dam construction
  • Groundwater abstraction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is cloud seeding?

A

Attempts to change amount/type of precipitation through dispersing chemicals into the air to cause cloud condensation.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is urbanisation?

A

Impermeable surfaces decrease infiltration and increase surface runoff and throughflow, increasing discharge rates.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is dam construction?

A

Dams increase surface water storage and evaporation, decreasing downstream river discharge.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What is groundwater abstraction?

A

Abstraction of water from aquifers happening faster than it is replaced, reducing groundwater flow and water table.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is a water budget?

A

The balance between inputs and outputs to a drainage basin. This makes drought and floods identifiable, (the former when output exceeds input, the latter when input exceeds output).

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is a river regime?

A

The annual variation in the discharge of a river.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is a storm hydrograph?

A

A graph showing short term variations in river discharge, usually before, during, or after a storm. The shape depends on various physical and human factors.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What factors can influence the shape of a storm hydrograph/discharge?

A

Land use, soil type, rock type, drainage basin shape and relief, vegetation, duration and intensity of precipitation, etc.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What is a deficit in the hydrological cycle?

A

A drought - UN defines as an extended period of deficient rainfall relative to the statistical multi year average for a region.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What are the physical causes of drought?

Study These Flashcards
A
  • Meteorological
  • Agricultural
  • Hydrological
  • Socio-economic
25
What is a meteorological drought?
Occurs when long term precipitation is much lower than normal but no consensus regarding the threshold for an official drought.
26
What is an agricultural drought?
Insufficient soil moisture to meet the needs for a particular crop at a particular time.
27
What is a hydrological drought?
Deficiencies in surface and sub-surface water stores, including rivers, reservoirs, lakes, and groundwater. Takes longer than the first two to reach the groundwater stores.
28
What is a socio-economic drought?
Water demand for social and economic purposes exceeds water availability. Depends on supply and demand.
29
What in the global atmospheric circulation system?
Hadley -> Ferrel -> Polar
30
What is the ITCZ?
The inter-tropical convergence zone is a belt of low pressure around the tropics that moves up and down. The heat that makes the air rise also increases evaporation rates so when it arrives it brings a wet season, and when it leaves it brings a dry season.
31
How can the ITCZ be blocked?
The high pressure zone on the outer end of the Hadley cell can block the arrival of the ITCZ resulting in drought e.g in the Sahel region (also since it is continental).
32
What is a mid-latitude blocking anticyclone?
33
What is ENSO
El Nino Southern Oscillation is a large mass of warm water in the Pacific pushed by currents and trade winds. However every 7ish years these weaken, pushing the warm water and rain to move east to the coasts of South and Central America. The Pacific countries of Australia experience drought.
34
What is La Nina?
Trade winds intensify instead of weakening, causing the water to be pushed further west, causing drought in Peru and California.
35
How have human activities contributed to drought risk?
Abstraction has reduced water flow downstream. Deforestation has reduced vegetation cover in the drainage basin, causing a reduction in evapotranspiration and therefore decreasing rates of precipitation (and also changes soil conditions). Additional risks include pollution, e.g studies found aerosol use in Europe and North America have caused drought in the Sahel region.
36
What are the impacts of drought on wetland ecosystems?
Reduced supply of water leads to progressive loss of habitat, and soil erosion. Gaps in the food chain left by dying out species will cause more species death.
37
What are the impacts of drought on forest ecosystems?
Loss of foliage, impaired growth, and pests in trees in the ecosystem. Dieback will cause habitat loss and the release of carbon stored, creating a positive feedback loop.
38
What are the meteorological causes of flooding?
Heavy rainfall associated with storms can cause flash flooding. In the Uk this can also be the result of mid latitude depressions. Monsoons can also cause extreme flooding.
39
What human actions can increase flood risk?
Increasing population leads to the removal of vegetation to make way for human settlements and agriculture, increasing runoff. Increasing soil erosion also increases deposition in the river so they can't carry as much water.
40
What happened on the Missisippi river?
Hard engineering (Channelisation) by straightening the river/cutting through meanders. This led to major flooding for many locals as the artificial levees and meanders constricted the flow of the river.
41
How will climate change impact the water cycle?
Climate change will cause increased flooding due to increased precipitation in low pressure regions. Melting permafrost will cause initial increase in channel flow followed by major decrease. High pressure systems will experience more severe drought.
42
What are the uncertainties in the future of the global hydrological system?
Uncertainty over population change, scientific advancement, government responses, positive and negative feedback loops, ENSO etc.
43
What is water insecurity?
The lack of ability to meet the socio-economic and agricultural needs of the population in a sustainable manner.
44
What are renewable water resources?
Long term total of renewable water sources. These are internal and external.
45
What is water stress?
Not much renewable water sources for the population. Includes significant restrictions on water use, tension and conflict over water, food insecurity and declining standards for clean water.
46
What is water scarcity?
Very low renewable water resources. Includes unsatisfied demand, open conflict, over-extraction of water and insufficient water flows to the environment.
47
What is absolute water scarcity?
Extremely low water resources. Widespread restrictions and rationing.
48
What are the physical causes of water insecurity?
Increasing variability in precipitation patterns. Water pollution. Warm waters = more bacteria growth. Saltwater encroachment.
49
What are the human causes of water insecurity?
Increasing demand for water (growing middle class). Mechanisation/industrialisation of agriculture. Over-abstraction of groundwater. Pollution and contamination of water.
50
What is the projected increase for global water demand by 2050
55%
51
What are the 3 dimensions of water scarcity?
- Availability (Physical lack of water). - Access (Bad management of resource by institutions). - Utilisation (Inadequate infrastructure to use water).
52
Why are water prices rising?
Rising prices all around the world as cost of infrastructure and desalination/cleaning is high. World bank/IMF loans urged privatisation so competition would lower prices but this made it inaccessible for much of the population.
53
Why is water supply important?
It's essential for everything we do - food, manufacturing, energy production, social services etc.
54
Why is environmental sustainability necessary?
Freshwater ecosystems provide many services. E.g wetlands stop flooding. Also provide food and water storage plus socio-economic benefits like recreation.
55
What are the impacts of high competition for water supply?
Conflict. This often has the biggest impact on vulnerable groups like social needs for drinking water and the environment.
56
Why does water supply need to be managed?
To minimise risk of insecurity or conflict. Can include technology and human attitude changes.
57
What hard engineering schemes can manage water supply?
Artificial structures including water transfer. E.g China's South-North water transfer. Also mega dams like in ethiopia, and desalination plants.
58
What hard sustainable supply schemes can manage water supply?
Working with locals to come up with soft engineering strategies. These usually work with natural processes. this includes water supply/quality regulation, and the moderation of extreme weather events.
59
What is integrated drainage basin management?
All players come together to create an agreed upon framework for the sustainable management of the river basin.

Geography (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions