Water Cycle Flashcards
What physical factors led to the big dry in Australia between 1999 and 2008?
El Niño led to the reversal of trade winds leading to high pressure over Australia and decreased conventional rainfall
The EGHE results in an expanding Hadley cell reducing the variance in temperature between the poles and the tropics reducing the amount of frontal rainfall
Leading to meteorological drought
What percentage of global water is in the oceans and freshwater?
Oceans- 96.5%
Freshwater- 2.5%
Of global freshwater, what percentage is held in glaciers and ice caps vs groundwater vs surface and other freshwater?
Surface/ other freshwater -1.2%
Groundwater- 30.1%
Glaciers and ice caps - 68.7%
Of surface freshwater, what percentage is held in lakes vs permafrost vs Rivers
Permafrost - 69%
Lakes - 20.9%
Rivers - 0.49%
What is an example of a pest that the forest stress positive feedback sequence can reduce resistance to?
The bark beetle
What we’re the economic impacts of the big dry in the Murray-Darling basin
Basin provides 50% of Australias agricultural output
Drought led to livestock deaths and reduced crop growth
Reducing economic revenue in wool + meat
How did hydrological drought occur in the big dry?
The meteorological drought from the El Niño and EGHE forced people to remove water by groundwater abstraction, resulting in greater hydrological drought as water was removed from stores
What we’re the social effects of the big fry in the Murray- Darling basin?
Basin provides 40% of municipal drinking water for Adelaide. Leading to a 40% reduction in reservoirs volume. More silt + salt led to decreased water quality
What led to hydrological drought on the Aral Sea?
Soviet Union removed water from 2 main feeder rivers by GWA for crop irrigation + cotton manufacture and fruit growth
What we’re the effects of Ground water abstraction on the Aral Seas volume and salinity?
Decreased water volume to 10% it’s original size by 2019
300% increase in salinity from greater concentration of fertilisers
What we’re the social effects of hydrological drought in the Aral Sea?
Salt flats exposed by sea shrinking blew salt into nearby water sources, salt polluted drinking water resulting in a high infant mortality rate, 1 in 10 children die in their first year from heart and kidney issues
What we’re the environmental effects of hydrological drought on the Aral Sea?
Decreased biodiversity
1/2 bird species remain
4/23 fish species remain
ALSO decreased drought resilience
What caused the drying of the wetland near the Euphrates and Tigris rivers?
Sadam Hussain dammed the rivers to attempt to help 260000 marsh Arabs living in the area
What we’re the effects of the southern Iraq dammings?
Wetland ran dry, becoming a semi arid desertification region with reduced biodiversity (decrease biological function)
What happened when the Euphrates and Tigris river dams were taken away?
Flow of rivers reinstated, some areas of marsh have recovered but not all, showing some resilience but not to same standard of diversity and functioning
What laws and conventions now help to protect ecosystems?
The Ramsay convention
Wetlands designated as internationally important
Funding and research for wetland preservation across 1800 wetlands and 160 countries
What is an example of flooding caused by prolonged rainfall in the UK?
3 successive storms (2020) Ciara, Dennis, Jorge
Led to 3,300 homes flooding
What led to the Pakistan 2022 floods?
Increased Arabian ocean temps from EGHE led to increased monsoonal rainfall by 190%
Glacial lake outburst from melting of pakistans glaciers, most glaciers of any nation in earth at 7000
What we’re the effects of the 2022 Pakistan floods?
Cost $40 billion in reconstruction costs
1700 people killed
What is an example of human river management leading to flooding?
Mississippi River
3500 miles of levees + channelisation increase velocity downstream led to 2011 floods of Louisiana farmland
What caused the Libya- Derby floods in 2023?
Storm Daniel- 400mm rain
Overwhelmed 2 clay filled embankment dams
Poorly maintained even though granted money for maintenance in 2012
What we’re the results of the Libya- Derna floods?
Let out combined 24 million cubic metres of water — flood waters nearly 3 meters high in some places
11000 deaths
