The Hydrosphere Flashcards
What are the 7 reservoirs of water in the water cycle?
Oceans
Land ice
Groundwater
Atmosphere
Living organisms
Lakes and rivers
Soil moisture
What is residence time (RT)?
The average amount of time that a water molecule is present in a reservoir of water
What is transfer rate?
The volume of water that is transferred over a period of time (e.g. litres per second)
What is the calculation for residence time?
RT = Volume of water in a reservoir / Mean transfer rate
What is the estimated volume of water in Earth’s hydrosphere?
1,500,000,000 km3
Which reservoir has the longest RT?
Groundwater (5000 years)
Which reservoir has the shortest RT?
Living organisms (7 days)
Which reservoir contains the largest volume of water?
Oceans (97% of water on Earth)
Which reservoir contains the smallest volume of water?
Living organisms (0.00004%)
Where does the energy that drives the water cycle come from?
The Sun
What is abstraction?
Taking water from a natural reservoir for human use
What are some examples of human activities which affect the water cycle?
Urbanisation, agriculture, deforestation, afforestation, global climate change
What are the effects of agriculture on the water cycle?
- Abstraction for irrigation can cause aquifer depletion (over-drafting)
- Heavy machinery or livestock trampling can cause soil compaction which would increase surface runoff
What is the link between interception and infiltration?
Water is more likely to infiltrate when slowed down by interception
What are the 4 factors which cause a change in the demand for water?
Change in population
Change in affluence
Change in industry
Change in agriculture
How does population affect demand for water?
Increased population leads to increased demand
How does affluence affect demand for water?
Increased affluence (wealth) leads to increased demand due to more money and appliances
How does industry affect demand for water?
Heavy industry (such as paper production) requires more water than the service industry
How does agriculture affect demand for water?
Intensive agriculture requires more water than small-scale or subsistence agriculture
What are the consequences of human impacts on the water cycle?
- Dynamic equilibria in the hydrological cycle are negatively affected as transfer rates are changed
- Reservoirs of water may become depleted and be unable to recover immediately
What is per capita water use?
The mean water use per person within a country (m3/yr)
What is GDP?
Gross Domestic Product is a measure of the monetary value of all goods and services produced within a country in a year (used as a measure of affluence)
What is a water footprint?
The volume of water needed for the production of goods and services consumed by a person or a group of people (e.g. business, country)
What are some abstractive uses of water?
Desalination, HEP, mining, transportation, heavy industry, domestic use