ESS Topic 4 Flashcards
Renewability of water
oceans - non renewable (long turnover time)
ice caps - non renewable
groundwater - middle ground
rivers - renewable
atmosphere - renewable (short turnover time)
Water Cycle Flows transfers
advection (Wind blown movement)
flooding
surface run-off
infiltration & precolation (water running through soils and rocks)
stream flow and current
Water cycle flows transformation
evapotranspiration - liquid to water vapour
condensation
freezing
Water cycle storages
oceans
soils
glaciers & ice caps
groundwater (aquifiers)
lakes
rive & streams
atmosphere
Human impact on water cycle
Withdrawals - domestic use, irrigation
discharges - addition of pollutants
changing speed that water flows - channelling underground, canalising, dams resoviors and barrages
diverting rivers
Ocean circulation systems
driven by differences in temperature and salinity
results in difference in water density driving ocean conveyer belt - distributes heat around world (affect climate)
Ocean conveyer belt
impacted by humans
seasons impact
currents move nutrients
Flash flooding
occurs when rainfall or snowmelt cannot infiltrate soil and runs off surface
caused by:
urbanisation
population sprawl
development then infrastructure
can cause water scarcity and water stress
How do humans use fresh water
domestic purposes
agriculture
industry
hydroelectric power generation
transportation
marking boundaries between nation states
desalinisation
most earth water is salinized
costs energy and money
salt as by-product gets dumped back in water increases density of water damages ocean-bottom systems
Sustainable freshwater sources
surface freshwater
underground aquifiers - often used unsustainably because of slow water flow
Freshwater issues
climate change disrupts rainfall
low water in rivers/streams
slow water flow resulting in sedimentation
underground aquifiers exahausted
freshwater contaminated
irrigation resulting in soil degradation
fertilisers and pesticides pollutes rivers and streams
industries release pollutants into surface water bodies
Freshwater solutions
increase freshwater supply
reduce domestic use of freshwater - become water efficient
grey water - recylcing
industries remove pollutants from their wastewater with water treatment plants
how to increase freshwater supply
reservoirs
redistribution
desalination plants
rainwater harvesting systems
artificially recharging aquifiers
Marine ecosystems and food webs
usually very biodiverse and have high stability & resilience
above continental shelf more productive than in deep oceans
Continental shelf
extension of continents under sea
creates shallow water
Classification of marine organisms
bethnic - living on or in sea bed
pelagic - living surrounded by water from above seabed or surface
ways to make fish farming more sustainable
livestock and poultry processing waste to make fishmeal - using scraps wasted in past
some carnivorous fish can get enough nutrients from alternative sources without eating other fish
impacts of fish farms
loss of habitats
pollution
spread of diseases
escaped species may survive to interbreed with wild fish
escaped species may outcompete native
causes of Overfishing
commercial fishing
fishing fleets
fishing vessels, supply vessels, factory ships
indiscriminate fishing gear
trawles drag huge nets
Water pollution types
anthropogenic
point source or non point source
organic or inorganic (carbon from living things)
direct or indirect
aquatic pollutants
floating debris
organic material
inorganic plant nutrients
toxic metals
synthetic compounds (POPs)
suspended soils
hot water
oil
radioactive pollution
pathogens
light
noise
biological pollutants
effect of organic material
affects water quality and biological indicators
effect of inorganic plant nutrients
soil erosion and land run off
