EQ1 Flashcards
What is blue water?
Visible
Surface water, supplying rivers, travelling underground, recharging aquifers
Available & recyclable
What is green water?
From interception, transpiration by vegetation or evaporation from surfaces
Ecological/hydrological functions
What factors affects water supply?
Climate
Geology
River Systems
How does climate affect water supply?
Season rainfall variation Climatic zone variation High rainfall at equator Recurring drought in tropical areas Relief rainfall CC Latitude
How does latitude affect water supply?
LOW STRESS at equator and ITCZ -> more rainfall
HIGH STRESS at seasonal tropics and poles -> less rainfall
What is the ITCZ?
Inter tropical convergence zone
Area encircling Earth where NE and SE trade winds meet
How do river systems affect water?
River flow is greater downstream
Higher temperature means more evaporation and more water loss
Seasonal change means variation in discharge and river regime
How does geology affect water supply?
Impermeable means more surface run off so high drainage density
Permeable means large quantities can be stored
What are examples of permeable rock?
Limestone, chalk, porous, sandstone
How is water finite?
- 5% in oceans
2. 5% in freshwater
Where is the freshwater located?
80% in trapped ice, snow and permafrost
20% in groundwater
1% easily accessible in lakes, ecosystems, atmosphere and rivers
What are some stresses of water?
Agriculture
Industry
Domestic
How is agriculture a water stress?
Food demands
Irrigation/water storage
Poor management results in fertiliser pollution, seepage, salinization, evaporation problems
Pop. growth
Inefficient as beef has 10 times more water cost than rice
Uses 69% of freshwater
How is industry a water stress?
Increasing industrialisation in India and China
HEP
Pollution
Often more efficient water use than agriculture
How is domesticity a water stress?
Smallest use of water - 10%
Huge variations between countries
Huge variation in quality
Demand is doubling every 20 years
What are the sources of water?
Surface Water
- rivers, lakes, reservoirs
- dams
Aquifers
How are dams a water source?
In the ST bring HEP
Flood control
Water supply
LT environmental and social impacts
How do aquifers work?
Sole source of drinking water for 1/4 of the population
Makes up 3/4 of Europe’s drinking water
It is abstracted faster than it is replaces in Middle East
Over abstraction
What is the over abstraction
LT costs
Reduction in water supply
Lowering water table
Seawater contamination
Define water stress
When the annual water supply per person is less than 1700m3
Define water scarcity
When the annual water supply per person is less than 1000m3
Define physical scarcity
When more than 75% of the country/region’s river flows are used
Define economic scarcity
When the development of blue water flow sources are limited by human and financial capacities
What human impacts are there on water?
Pollution Abstraction Deforestation Over irrigation (raises water table) Cloud Seeding with silver iodide
How does pollution affect water?
Sewage disposal - typhoid, cholera, hepatitis
Chemical fertilisers runoff into rivers & groundwater (eutrophication)
Industrial waste is pumped into rivers, oceans, waterways
Big dams trap sediment -> reduces floodplain fertility -> reduces nutrient flow ->damage fish & beach formation -> exposes so greater erosion
How does abstraction affect water?
Lowers water table
Seawater contamination
Rainfall can’t recharge stores in arid areas
Salt water incursion
What is salt water incursion?
Removing freshwater upsets the balance of freshwater and saline
How does deforestation affect water?
Reduces evapotranspiration
Increases surface run off
Define water insecurity
Not having access to sufficient safe water
What 3 factors affect water security?
Availability - supply & distribution network
Access - Freedom to use & income to buy
Usage - entitlement to & understanding of use and health issues
What does the Water Poverty Index involve?
Resources Access Capacity Use Environment
How is water wealth or improved water a lubricant of development?
Improved water -> sanitation -> food production -> better health -> wellbeing
Water wealth -> irrigation -> energy -> economic growth
How can you interfere with the water cycle?
Precipitation (deforestation, global CC)
River runoff (Dam construction, abstraction)
Groundwater availability (Infiltration rate, over abstraction, groundwater mining, land use change, over irrigation)
Pollution
Cloud seeding
What is the hydrological balance and how is it affected?
Mass balance change = water in - water out
Water in: climate, geology, quality, duration of flow
Water out: extraction, evaporation
What is the difference between a confined and unconfined aquifer?
Unconfined has permeable rock on top so water enters to refill and escapes out
Confined has impermeable rock all around so no water leaves or enter, has to be recharged
What are the positives and negatives of overextraction/overabstraction?
\+ water supply increases \+ better sanitation \+ lowers water borne disease rate \+ improved health & general welfare \+ used to support industries & creates better water infrastructure - potential for conflict - not sustainable for future use
What are the key players in water use?
Consumers
Gov.
Water companies
How have players failed?
GOV.
- lack of quality standards
- no policing/resolving conflict
- not providing infrastructure (dams, desalination plants, pipelines)
WATER COMPANIES
- capitalist economy
- not delivering/managing in a safe/reliable/cost effective way
- privatisation means profits are prioritised before the people
- TNCs don’t have the same interests as local companies
CONSUMERS
- excessive use
- contribute to ‘grey’ water
- demand increasing for lower prices
What is grey water?
polluted water
What are the different layers of the Earth’s atmosphere?
Atmosphere - gases surrounding Earth Hydrosphere - water on Earth's surface & clouds Cryosphere - frozen earth Biosphere - where living organisms are Lithosphere - crust and upper mantle
How would each atmosphere layer affect water supply?
Atmosphere (high light sun intensity means more evaporation)
Hydrosphere (Condensation means more rainfall)
Cryosphere (warmer temps means more meltwater)
Biosphere (More vegetation means more canopy, less soil erosion and less surface run off)
Lithosphere (surface run-off affected by geology permeability)
