mocks cramming - topic 4 - water Flashcards
Hydrological Cycle - Transfers
stays in the same state
▪ Flooding, Surface run-off
▪ Stream flow/currents
Human impact on water cycle
- Withdrawals (domestic use)
- Discharge ( pollutants to water)
- Changing speed of water flow and where it flows (canals, dams)
- Diverting river sections to avoid flood damage
Hydrological Cycle - Transformations
changes state
▪ Evapotranspiration: liquid to water vapour
▪ Condensation: Water vapour to liquid
Freshwater Issues:
- Climate change disrupting rainfall patterns: causing inequality of supplies
- Contaminated and unusable freshwater
- Fertilizers + pesticides pollute streams and rivers
- Underground aquifers are being exhausted (affects agriculture)
- Irrigation leads to soil degradation
Freshwater issues Solutions:
- Increase freshwater supplies by reservoirs, desalination plants, and rainwater harvesting
- Grey water recycling from shower, baths
- Replace chemical fertilizers with organic ones + reduce fertilizer use
- Irrigation: select drought resistant crops
- Water treatment plants
Continental shelf things
- shallow extensions of continents under seas
- 50% of ocean productivity but only 15% of its area
- light reaches there - photosynthesis
- countries claim it to exploit it
Phytoplankton
- single celled organisms that can photosynthesize
- responsible for almost half the global annual net primary production
Zooplankton
single-celled animals that eat phytoplankton and their waste
Impacts of fish farms
- Loss of habitats
- Pollution (antibiotics, feed)
- Spread of diseases
- Escaped species (genetically modified organisms) may survive to interbreed with wild
fish - Escaped species may outcompete native species (pop crash)
Eutrophication
- happens when too many nutrients from fertilizers (eg nitrate and phosphate) enter river/lake system
- algae that feeds on nutrients reproduce very quickly, blocking light from reaching bottom
- underwater plants that photosynthesise die, then algae dies after eating all the nutrients
- bacteria eat dead plants n algae, releasing nutrients back into water
- algal bloom cycle
bacteria uses all the oxygen in water, making it anoxic - causing everything living to die
Eutrophication Management Strategies:
Before:
- Ban or limit detergents with phosphates or use eco detergents
- Educate farmers about effective timing for fertilizer application
During:
- Treat wastewater before release to remove phosphates and nitrates.
- Divert or treat sewage waste effectively.
After:
- Pumping air through lakes
- Remove excess weeds physically or by herbicides
outline the water cycle
As the sun warms the Earth, liquid water found in lakes and oceans on the planet’s surface evaporates.
Moisture within the atmosphere eventually cools and condenses, until liquid water or snow falls back to the Earth as precipitation.
Runoff from rain eventually finds its way back to lakes and oceans, completing the most direct version of the water cycle.
how much of earth’s water storages is freshwater
~2.6%
how much of freshwater storages is in the form of ice caps and glaciers
over 80%
renewable vs non-renewable water sources
Renewable water resources are renewed yearly or even more frequently
however groundwater is non-renewable resource
sublimation
the conversion between the solid and the gaseous phases of matter, with no intermediate liquid stage. Used to describe the process of snow and ice changing into water vapor in the air without first melting into water.
Evaporansportation
water evaporates from plants, mainly through their leaves. This gets water vapor back into the air.
Advection
Transport of an atmospheric property (eg. heat) by the wind from one point to another.
Advective transfers occur either in the oceans by currents of seawater or by large-scale movement in the atmosphere where humidity (atmospheric moisture) is another important property.
impacts of agriculture on surface runoff and infiltration:
- Tillage of land changes the infiltration and runoff characteristics of the land surface
- Applications of pesticides and fertilizers to cropland can result in significant additions of contaminants to water resources
infiltration
when water soaks into the soil and moves into the pores and cracks of the rocks
impacts of urbanisation on surface runoff and infiltration:
- Point sources of contamination to surface-water bodies
- Point sources of contamination to ground water can include septic tanks, fluid storage tanks, landfills, and industrial lagoons
impacts of deforestation on surface runoff and infiltration:
- leads to the decreasing of interception and infiltration, because there are not trees to trap rainfall.
- increase the amount of surface runoff and increase the storm runoff in rivers. The erosive power is enhanced by the running water.
interception water cycle
precipitation that does not reach the soil, but is instead intercepted by the leaves, branches of plants and the forest floor
runoff
precipitation that does not soak into the soil but instead moves on the Earth’s surface toward streams
what drives ocean circulation systems
differences in temperature and salinity.
The resulting difference in water density drives the ocean conveyor belt, which distributes heat round the world, and thus affects climate
shallow vs deep currents
shallow currents are warm, transfering heat to and absorbing heat from air
deep currents are cold
how may climate change alter rainfall patterns
- altering temperature and moisture which does some things
factors contributing to increase in water demand
- Irrigation
- industrialization
- population increase
how can water use be managed
- making new buildings water efficient (eg. rainwater for sanitation and showers)
- fitting new homes with more water-efficient appliances (dishwashers and toilets)
- in some rural areas drought resistant crops should be planted to reduce the need for irrigation
- organic fertilizers cause less pollution
large scale societal impacts of water shortages
- inequity of use
- mass migration
- civil unrest / wars
aquifer
a body of permeable rock which can contain or transmit groundwater.
effects of warmer climate on water supply
droughts and floods could become more frequent, severe and long-lasting
delta definition
wetlands that form as rivers empty their water and sediment into another body of water
Rainwater harvesting
- used to replenish underground supplies
- relatively inexpensive
- allows local communities to develop and maintain the required structures themselves.
Diverting Surface Water
- divert surface water into ground
- reduce losses from evaporation
- compensate for variations in flow
- improve quality
surface water
water that flows or rests on land and is open to the atmosphere.
Dams and Reservoirs
- store water for irrigation and drinking
- dams can provide power and help control floods :)
- dams can have undesirable social/environmental impacts :(
drainage basin
an area of land where all flowing surface water converges to a single point (eg. a river mouth), or flows into another body of water (eg. a lake or ocean)
Wastewater reuse
- reused for different purposes in many countries
- non-potable water is used for irrigation and industrial cooling
- supplement drinking water supplies with water treatment
desalination
- salty water that has been turned into freshwater
- cost has dropped
- relies heavily on energy from fossil fuels and hence raises waste management and climate change issues
influences on controversiality of harvesting of marine mammals
- eg. seals, whales
- spiritual reverence
- cultural
- politically influential
- fondness of taste
principal ethical issues in fisheries
- poverty
- the right to food
- legislation
- overfishing and ecosystem degradation.
issues with the depletion of a nation’s fishery resources
- moral failure by society to maintain the natural environment
- compromises food security, threatening vulnerable communities
- reduces the livelihood opportunities of future generations
sustainable management of fisheries strategies
- use of quotas
- designation of marine protected areas (exclusion zones)
- restriction on types and size of fishing gear (including mesh size of nets)
aquaculture definition
breeding, raising, and harvesting fish, shellfish, and aquatic plants.
- Basically it’s farming in water
major commercial fishing methods
- trawling
- driftnet fishing
- deep sea aquculture cage
- purse seines
trawling
- trawl nets towed by a boat through the water column or along the sea floor
- nets shaped like a cone/funnel
driftnet fishing
- vertical nets
- fish passively - fish r caught when they swin into it and are caught by gills
- high by-catch rate - bad impact on fauna
deep sea aquaculture cage
large cages are dropped below the surface of the ocean and held down by an anchor
purse seine fishing
- A vertical net ‘curtain’ surrounds the school of fish
- bottom is drawn together to enclose the fish, like tightening the cords of a drawstring purse.
capture fisheries vs aquaculture
capture fisheries catch wild fish, aquaculture farms them
closed or recirculating aquaculture system
An aquaculture system that is not connected to the natural environment, that recycles most or all water used for production.
freshwater and marine pollution sources (6)
- industrial waste
- sewage/wastewater
- marine dumping
- accidental oil leaking
- burning of fossil fuels
- chemical fertilizers/pesticides
aquatic pollutants (7)
- floating debris
- organic material
- inorganic plant nutrients (nitrates and phosphates)
- toxic metals
- pathogens
- light, noise
- biological pollutants (invasive species).
Suspended Matter - water pollution
- pollutants that don’t dissolve in water
- called particulate matter
- suspended particles eventually settle and cause a thick silt at the bottom
- This is harmful to marine life that lives on the floor of rivers or lakes
parameters to determine water quality
- pH
- temperature
- turbidity (suspended solids)
- salinity
- nitrates and phosphates
- flow velocity
anoxic
no oxygen
Biochemical oxygen demand (BOD)
- measure of the total demand for oxygen by living and chemical components in a water body
biological indicators in water
- aquatic plant and animal life that are susceptible to specific types and levels of pollutants
- level of pollution in water can be indicated by the species living there
- Typically, unpolluted water = greater diversity of organisms
Biotic index
- a scale 1-10
- gives a measure of the quality of an ecosystem by the presence and abundance of the species living in it
hypoxia
water conditions where the concentration of oxygen is so low that it is detrimental to organisms and very few organisms can survive in those conditions
water pollution management strats
- reducing human activities that produce pollutants
- reducing release of pollution into the environment (for example, treatment of wastewater to remove nitrates and phosphates)
- removing pollutants from the environment and restoring ecosystems (for example, removal of mud from eutrophic lakes and reintroduction of plant and fish species).
