topic 4: water Flashcards
1
Q
effects of humans altering the natural flow of water on ecological systems
A
- extracting water from rivers and streams, reduces water level and flow rates, changes environment for aquatic species
- draining wetland areas to increase agricultural land, replacing wetland habitats with monoculture, loss of biodiversity
2
Q
human impact on water quality
A
- discharge of industrial waste (toxic chemicals) into rivers, lakes and oceans
- deforestation leads to soil erosion, siltation of lakes and rivers
- surface runoff leaching pesticides and fertilizers
3
Q
siltation
A
- water pollution of sediments, soil erosion
4
Q
hydrological cycle definition
A
describes the movement of water on the planet
5
Q
hydrological cycle storages
A
- Oceans
- Surface waters, such as streams, rivers and lakes
- Ice caps and glaciers
- Soil moisture
- Water vapour and clouds within the atmosphere
- Groundwater within aquifers
- Organisms, such as plants and animals.
6
Q
flows definition (hydrological cycle)
A
- process of water moving to different storages = a flow
- flow is either transformation or transfer
- transformation = change in state
- transfer = change in location
7
Q
hydrological cycles flow transfer
A
- advection
- stream flow
- flooding
- groundwater flow
- percolation
- absorption
- infiltration
- surface run-off
- precipitation
- advection
8
Q
hydrological cycles flow transformation
A
- evaporation
- transpiration
- evapotranspiration
- sublimation
- condensation
- melting
- freezing
- deposition
9
Q
water flow into the atmosphere
A
- liquid water turns to water vapour from the sun
- evapotranspiration (plants) and sublimation (snow and glaciers)
- water vapour rises, cools and condenses into clouds
- clouds transported within the atmosphere by advection (wind)
10
Q
water flow out of the atmosphere
A
- clouds grow and become heavy
- fall as precipitation returning to earth
- temperatures are low
- 80% of precipitation falls on the ocean
11
Q
water flow on land
A
- impacted by topography, geology, soil and vegetation cover
- flow of water on land called surface runoff
- if precipitation is snow/ turns to ice movement of water is reduced
- vegetation slows the movement of water, leaves catch raindrops, infiltrate into soil
- decayed plant matter can absorb water
- filtration rates > sandy soils than on fine grain soils
- fine grain soils have smaller pore spaces for the water to seep through
12
Q
water flow into groundwater
A
- permeable surfaces the water can flow further underneath the soil, percolation
- water moves into aquifers and contributes to groundwater storage
- vegetation encourages infiltration which can increase the amount of stored groundwater
13
Q
water flow out of groundwater
A
- groundwater can flow directly into the sea, streams or rivers
- during droughts, reduction in groundwater flow can impact river levels and therefore river ecology
14
Q
water flow into surface waters
A
- precipitation contributing to surface runoff can go into streams, rivers and lakes
- flow of water is increased
15
Q
runoff into surface waters
A
- can flow from streams, rivers and lakes into the ocean
- cause flooding due to capacity of rivers, streams and lakes exceeded
16
Q
global conveyor belt definition
A
- movement of ocean water
- distributes heat energy, impacts regional weather around the world
17
Q
water density temperature
A
- colder = more dense
18
Q
water density salinity
A
- greater salinity = more dense
19
Q
how global conveyor belt works
A
- warm water moves towards the poles, water cools releasing heat increasing temp
- cold water moves towards the equator, water absorbs heat from surroundings lowering the temp
20
Q
forest vegetation impact on hydrological cycle
A
- trees are stores absorbing water, reducing flow
- more runoff due to no root system to anchor soil
- reducing infiltration and percolation as runoff will flow faster, increased risk of flooding, lots of sediment reduce carrying capacity and water quality
- intercepting rainfall protecting soil
21
Q
agriculture impact on hydrological cycle
A
- largest user of water, expected increase due to population and more meat based diets
- agricultural activity requires excessive amounts of water, decreasing fresh water availability
- excessive irrigation with poor drainage increases soil salinity, unsuitable to grow crops
- water can become polluted with pesticides and fertilizers
- toxic for aquatic organisms, eutrophication of ecosystems
- increase of nitrates in groundwater which is linked to diseases when drank
- pathogenic livestock waste washed by runoff into streams and rivers, lowering oxygen content in aquatic ecosystems.
22
Q
urbanization impact on hydrological cycle
A
- flow of water becomes contaminated with waste, oil and toxic metals
- runoff diverted into drainage systems into rivers and streams
- increased risk of flooding
- aquatic habitats can become degraded from polluted runoff
- reduced evapotranspiration
23
Q
urbanization definition
A
- movement of people from rural areas to towns and cities
- large areas of concrete and tarmac, impermeable
24
Q
eutrophication
A
- nutrients entering body of water causing anoxia
25
eutrophication steps
- increased nutrients entering body of water causing algae to bloom
- no sunlight reaching due to algae cover
- causes algae under the water to die
- bacteria decomposing the algae uses up oxygen making the body of water anoxic
- all living organisms in the lake die
26
fix urbanization hydrological cycle issues
- creating roads made of porous material so water can infiltrate and percolate to groundwater
- diverting water from roofs and roads into infiltration trenches or soak away, creates green spaces and areas for wildlife within urban environments
27
fix agriculture hydrological cycle issues
- crops that need less water
- efficient watering methods, drip irrigation
- don't use fertilizers, pesticides or manure near water sources, prior or during rainfall
- limit use of nitrogen fertilizers
- collect and manage animal waste
- introduce natural predators for pest control
28
case study
| unequal distribution of rainwater
- atacama desert average 1mm per year
- cherrapunji average 11.7m per year
- water needs to be managed and stored to have a continual supply
29
issues accessing water
- lack of knowledge and skills, finances, political leaders making water a priority
- urban areas, wealthy, unmarginalized social groups more likely to have access
- people with less money pay more as water infrastructure takes lots of resources
30
water stress definition
- insufficient amount of available water to meet demand
| - includes unuseable water due to water quality
31
issues that contribute to water stress
- freshwater sources being overused
- pollution of freshwater sources
- inefficient water use by individuals or industries, leaks, poor irrigation
- climate change altered rainfall
32
rivers without borders
- many rivers systems are shared within countries
- water sources that originate outside of their borders, that country can control their water
- can cause conflict between the countries
- usually formal agreements written to resolve conflict
33
case study
| ethiopian grand renaissance dam
- biggest dam in africa
- ethiopia can control the flow of the nile which egypt relies on
- egypt threatened militaries
- came to an agreement, ethiopia filling the dam gradually
34
benefits of a reservoir
- generate hydropower
- flood control
- navigation, transport routes along site shores
- fisheries
- recreational, aesthetic and scenic values
- control of water quality filtering sediment
35
impacts of a reservoir
- change of habitat, terrestrial to aquatic
- relocation of people
- change of flow to the water, diverted for other use
- loss of fish and mammal migration routes, blocking with dam walls
- sediment behind the dam wall reduces holding capacity of reservoir
36
increasing water resources
| artificial recharge
- building a ditch above an aquifer zone to intercept runoff giving it more time to percolate
- water can be pumped directly from rivers or reservoirs
37
increasing water resources
| rainfall harvesting
- collection of precipitation falling on roofs or buildings
- cheap and easy
- able to be filtered and disinfected for drinking
38
increasing water resources
| desalination
- producing freshwater from sea water
- used in regions with access to cheap energy
- reverse osmosis used through a semipermeable membrane to remove the salt
39
increasing water resources
| greywater
- reusing water that is clean enough to be used again, baths, showers and washing machines
- cost effective
40
increasing water resources
| redistribution
- moving water from areas of low demand to high demand
41
reducing water demand
- increasing water efficiency
- public awareness campaigns
- education in schools
- economic incentives, increasing cost of water, fines for wasting water
- government policies
- reducing meat intake
42
importance of phytoplankton and algae
- supporting trophic levels
- absorbing carbon dioxide
- producing oxygen through photosynthesis
43
aquatic food chain
- primary producers eaten by primary consumers (zooplankton, microscopic animals)
- primary producers dependent on amount of sunlight, suitable temperature, available nutrients
- primary consumers eaten by secondary consumers (shellfish, fish)
- secondary consumers eaten by tertiary consumers
(predatory fish, mammals, seabirds
- if large numbers of secondary consumers are removed it will impact the whole food chain
44
aquatic food chain simple
- primary producers
- primary consumers
- secondary consumers
- tertiary consumers
- quaternary consumers
45
aquaculture (fish farming)
- providing a food source
- livelihood bringing people out of poverty
- invasive species can escape
- nutrient buildup
- transfer of disease and parasites to migrating fish
46
why increasing demand of fish
- population growth
- health benefits of eating fish
- more people that can afford fish
47
case study
| canada seal hunting
- traditional from the inuit people in canada
- integral part of culture and traditions
- inuit only 3% of seals hunted globally
- commercial exploitation = threat to seal population
- inhumane methods of killing
- most of the meat is wasted
- seals incorrectly blamed for cod fishery collapse (overfishing not seals)
- less seal habitats due to melting ice
- canada regulates seal hunting through government policies however not enforced
- economic value from seal hunting
48
capture fisheries
- increased due to popularity of fish
- small scale to commercial fishing
- improvements in fishing technology and number of ships
- increased efficiency of fishing
49
fish yield
- only renewable if the rate of removal does not exceed growth rate
- maximum sustainable yield should be taken into consideration otherwise risk of overfishing and extinction
50
why is overfishing common
- nobody has property rights to fish as they travel and migrate
- need to sacrifice short term gain for future gain
51
Marine Protected Areas (MPAS)
- areas where fishing is banned
| - usually areas of high biodiversity or habitats of threatened species
52
case study
| newfoundland cod fisheries
- largest cod sticks in the world
- 1950s modern technology able to catch more
- 1968 caught 800,000 tons of cod
- warnings to reduce catch ignored
- loss of jobs due to no more fish
- 2011 fish stocks beginning to recover but still low
53
tragedy of the commons
- neglecting future needs and societal needs for current gain
54
case study
| iceland cod fisheries
- decline in fish stocks, government took action
- protecting waters from other countries
- restrictions on fishing gear and fleet sizes
- strict quotas
- banning disposal of bycatch, food not wasted
- catching a variety of fish reducing pressure on cod
- use of MPAs
- rules are enforced
55
aquaculture definition
- farming of aquatic organisms
- aquaculture expected to keep growing
- 62% of all fish consumption by 2030
56
environmental impacts of aquaculture
- loss of habitat as land is cleared, such as mangroves
- loss of aquatic habitats
- increase in organic sediments: fish waste, fish food, medicine
- sediments can cause eutrophication or algal blooms which can kill fish
- medicine and hormones can impact other aquatic life
- spread of disease to fish outside of cages or all fish in cage
- escaped fish can dominate environment and become invasive
57
environmental impacts of aquaculture
- loss of habitat as land is cleared, such as mangroves
- loss of aquatic habitats
- increase in organic sediments: fish waste, fish food, medicine
- sediments can cause eutrophication or algal blooms which can kill fish
- medicine and hormones can impact other aquatic life
- spread of disease to fish outside of cages or all fish in cage
- escaped fish can dominate environment and become invasive
- predators can get caught in the fish cages
58
case study
| shrimp aquaculture in thailand
- food security
- over 1 million people employed
- more income than previous rice farming
- loss of mangroves
- rapid transmission of diseases
- eutrophication
- 1990s international pressure for sustainable shrimp aquaculture leading to new legislation and management of wastewater
59
purpose of mangroves
- breeding areas for fish
- habitat for species
- protection from coastal erosion, flooding, storm damage
60
sources of water pollution
- sewage
- industrial waste
- agricultural runoff
- urban runoff
- land development, forest clearance, soil erosion, sediments into water
- landfill sites
- atmospheric input, acid rain
- materials dumped into sea
- hot water, lowers oxygen content
- oil, lowers oxygen content, death of animals in the area
plastic
61
issues with eutrophication
- water unsuitable for drinking
- reduced recreational use water, swimming, fishing
- reduced commercial value, not able to fish, navigation routes
- increased water diseases
