agrc1031
What is the routing equation?
I - O = Ds / Dt
How is water quantified in a catchment?
I-O = difference in P
What are autotrophs?
Organisms that can fix inorganic carbon to make organic carbon molecules
Why does latitude affect temperature?
Insolation changes. It is greater in equatorial regions (vs polar regions) because of the angle of incidence of the sun's rays
What is insolation influenced by?
Latitude Composition of the atmosphere (aerosols: smoke, dust, gases) Presence of clouds Surface type Albido Season
What affects the oceans transport of energy?
Salinity Melting of glaciers
What is the subtropical ridge?
Where Hadley cells deposit dry air, resulting in arid zones
Gross primary production (GPP)
The total amount of solar energy captured by photosynthesis over a given period of time
Insolation
The total amount of solar radiation received in a given area during a given time
What are El Nino conditions?
The tradewinds weaken due to a change in air pressure between regions and equatorial currents weaken. There is warmer than average water in East equatorial pacific. There is an increase in convective precipitation in South America (flooding, poor fishing in Peru due to lack of upwelling), drought in Australia (bushfires, displacement of wildlife)
What are the two types/terms of primary production?
gross and net
How much more does Australia grow than other counties?
growth rate is twice the world average and 8 times the western average
What are stock and domestic rights and riparian rights (the same)?
held by landowners in rural areas to allow access to water for the purpose of domestic use within the property, tradeable only with land
What are sodosols?
influenced by sodium
What can chemical pollutants be classified as?
inorganic (metals, metalloids, radionuclides), organic (carbon-based such as hydrocarbons, polychlorinated biphenyls, detergents, insecticides etc), includes nutrient pollution, sources include agricultural runoff, industrial effluents, human and animal wastes, waste disposal
What is life reliant on?
inputs of energy from the sun, the cycling of matter (water, N, P, K etc)
How old is Phanerozoic soil?
less than 570 myo
What are other sources of climate variation?
pacific decadal oscillation (north pacific), north Atlantic oscillation, Atlantic thermohaline circulation
What are used to measure evapotranspiration?
pan evaporators and lysimeters
What is the fertilizer use efficiency equation?
plant uptake/fertilizer inputs x 100
What is the nutrient cycle?
plants, heterotrophic food chain, microbial decomposition and consumption, mineralization, gaseous losses, soluble nutrients, leaching losses, weathering input and atmospheric input
What are podosols?
podzols
What is non-point-source water?
pollutants originating from multiple sources over a relatively large area (sometimes called 'diffuse pollution') include runoff, drainage or seepage, some air pollution, urban runoff, septic systems
What is Atlantic thermohaline circulation?
salty tropical water is carried on the gulf stream, heavy salty water (because of evaporation) sinks south of Greenland. Variations in rainfall, temperature etc influence flow. A weak ATC results in colder than average north Europe and a strong ATC results in a warmer than average north Europe
What are some features of dermosols?
quite common, fertile, good agricultural soils
What are rudosols?
rudimentary soil development
What pollutants are important in soil degradation?
salt fertilizer acids/alkalis organics municipal waste hydrocarbons heavy metals
what does evapotranspiration depend on?
the amount of vegetation growth latitude (input energy) temperature cloudiness wind speed humidity (rainfall and proximity to water)
how is evaporation measured?
the amount of water that is evaporated from an open, standardized pan, which is indicative of water evaporating from bare soil or open water
What is mass balance?
the application of newton's law (conservation of mass) to analysis of system mechanics and dynamics. Change = input-output
What is an active channel?
the area outside of the river that is likely to receive sedimentation
What is ARI?
the average recurrence interval, a statistical estimate of the average period in years between the occurrence of a flood of a given size
How does water move in natural situations?
turbulent flow, woody detritus, cobbles, boulders, aquatic plants all cause impediments to flow
When does granite become podsol?
where there is organic acid leaching, vegetation specific, high rainfall and low temperature
What are some features of sodosols?
widespread, formed on many types of landscapes
What does carbon in surface water depend on?
wind speed, temperature and concentration
What methods can be used to minimize erosion and land effects?
windbreaks (wind erosion), riparian forest buffers (reduce sediment erosion, phosphorus runoff, nitrate), wetland restorations (water quality improvement, flood attenuation), filter strips (reduce slide bank erosion, trapping sediments and pollutants), grass waterways (reduce erosion)
Are our energy reserves enough for 40-50 million peoples?
yes, Australia has limited reserves of oil but extensive reserves of natural gas, coal and uranium, however fossil fuels like coal and gas contribute to global warming. This is not sustainable
Can we produce enough food for 40-50 million people?
yes, because already most of it is exported. However this means that the people who import our food will suffer and soil fertility may decline in the future
Why does australia's nitrogen budget vary across the continent?
fertility of the land and soil type, land formation, rainfall patterns
What are anthropogenic causes of eutrophication?
fertilization, human/animal waste, detergents
What are the causes of extinction?
#1 reason is land clearing (100 million native Australian birds, mammals and reptiles die yearly in qld due to land clearing) #2 is invasive species (cats in Australia kill up to 75 million native animals per day)
What is the formula that explains soil formation?
- S = f (cl, o, r, p, t) - f = formation, cl = climate, o = organism (macro and micro), r = relief (topography), p = parent material, t = time
What happens when air descends on an impermeable substances such as land?
- high pressure ridges form that are associated with dry air which corresponds with the world's arid regions
What are characteristics of wet-dry tropical regions?
- wet and dry seasons, they are on the periphery of the ITCZ, when the ITCZ moves further away, climate becomes dominated by the STR, hence the dry season, drought resistant plants
What is the sustainable diversion limit of the murray river?
10,872 GL/y (13,362 GL used in 2009 for consumptive use)
What is absolute scarcity?
0-1000 m3/person/year
How are environmental flows determined?
1. Identification of a river system's ecological value 2. Identify critical factors and assess their values/significance 3. Formulate environmental flow/water level decisions based on objectives and policies of local, regional and national management plans 4. Ongoing management to ensure that environmental flows/water levels provide intended outcomes
Where are wet equatorial regions found?
10 degrees N to 10 degrees S
What percentage of units of energy is captured through consumption?
10%
What is water stress?
1000-1700m3/person/year
How much ice melts per decade?
15.1%
What is water vulnerability?
1700-2500m3/person/year
What are stream orders?
1st - 4th, with increasing order there is decreasing slope, function change, less erosive and more depositional, in general 1st to 4th order streams are connected to forest ecosystems, larger systems can be 10th-11th order
What percentage of units of solar energy is captured through photosynthesis?
2%
What is split fertilizer application?
2-3 multiple applications, drip fertigation and micro-spray fertigation
How much carbon is stored in soil?
2/3
About how much solar energy is absorbed by the atmosphere?
20%
How much water is used for industrial processes?
20%
How often does soil carbon turn over?
25 years
How much more energy does N2O absorb than CO2?
289 times more over next 20y
About how much solar energy is reflected by clouds, other atmospheric components and reflective surfaces?
30%
How much runoff do people use?
35% directly and 20% indirectly
How does water scarcity affect the world?
40% of the world faces some sort of water scarcity, expected to increase to 66% by 2025
Where are wet-dry tropical regions found?
5-30 degrees N and S
About how much of the incoming energy to Earth penetrates the surface?
50%
Where does emitted CO2 go?
55% stays in the atmosphere, 25-30% dissolves in the ocean and 15-20% goes into the biosphere
How is cryptozoic soil?
570 - 4500 myo
What are trigger points determining if a bore has been affected by CSG extraction?
5m drop in bore water levels for consolidated aquifers (sandstone, fractured rock), 2m drop in bore water levels for alluvial aquifers
What percentage of ecosystems are being degraded or used unsustainably?
60%
Where do methane emissions come from?
60% agriculture, 20% fossil fuels and 20% natural
What are some features of ferrosols?
600-2000mm rainfall, mainly on basalt, good agricultural land
How much must food production increase for the growing population by 2050?
70%
How much water is used for irrigation and agriculture?
70%
Where does irrigation water come from?
70% comes from surface water
Where is water used?
70% on agriculture, 20% on industry and 10% on domestic use
Where is nitrogen in nature?
78% in atmosphere, 75,000 Mg/ha, lots in mantle, some in crust, very small percent consisting of mainly ocean, some in soil
Where is earth's water?
97.5% in oceans, 68.7% of freshwater in glaciers, 30.1% in groundwater, 0.4% in lakes and rivers
What is biological pollution?
> 2Mt sewage and industrial/agricultural waste discharged daily into waterways around the world, one of the most significant forms of pollution because of the many people living without adequate sanitation, water may contain infectious agents able to cause diseases in humans/animals, typically caused by contamination with human/animal waste, may include bacteria, protozoans, viruses, helminths
Biomes
A broad, regional type of ecosystem characterized by distinctive climate and soil conditions and a distinctive kind of biological community adapted to those conditions. Regions with similar climate often share similar biota, giving rise to biomes.
What is the temperature & humidity method of classifying Australian climate zones based on?
A set of definitions relating to summer and winter conditions: hot, humid summer hot, dry summer, mild winter hot, dry summer, cold winter warm summer, cold winter mild/warm summer, cold winter
What are the IPCC report scenarios?
A1 (rapid economic growth, low population growth, rapid spread of new technologies) A2 (more divided, regionalized world, rapid population growth, fragmented, slow economic and technological growth) B1 (rapid then reduced growth similar to A1; integrated, global environmental sustainability) B2 (more divided, regionalized world, local and regional environmental sustainability)
What is the A1 scenario broken into?
A1T (non-fossil fuel intensive), A1B (balanced, all energy sources) and A1F1 (fossil fuel intensive)
What is an easterly trough?
An area of low pressure in the inland side of the great dividing range sandwiched between coastal moist air and continental dry air, it is formed by intense heating of the land during summer months.
What are the sources of soil degradation?
Agriculture industry construction manufacturing mining transport urban
What is the environment?
All of the things that happen in a place and their interactions. Earth is the only place we currently know of that can support life.
What is an ecosystem or biophysical environment?
An environment that includes both living and non-living things. The living and non-living things are linked by energy and material transfers.
Photoheterotroph
An organism that depends on light for most of its energy and principally on organic compounds for its carbon.
Photoautotroph
An organism that harnesses light energy to drive the synthesis of organic compounds from carbon dioxide.
Chemoautotroph
An organism that needs only carbon dioxide as a carbon source but that obtains energy by oxidizing inorganic substances.
Chemoheterotroph
An organism that obtains carbon from organic molecules but obtains energy by oxidizing inorganic substances.
Precipitation
Any form of moisture condensing in the air and depositing on the ground
What are the climatic zones associated with?
Assemblages of different living species
Why is it colder up a mountain?
Atoms of gas are further apart so there is less energy as they collide
How does BOD relate to wastewater discharge?
BOD peaks shortly after the point of discharge, then gradually decreases, there is a rapid BOD increase because of microbial decomposition of available (discharged) organic materials, oxygen in water is not adequate to support high level of microbial decomposition, so DO decreases
Where have there been recent flood events in AU?
Bundaberg 2013, Brisbane 2011, Rockhampton 2011, Toowoomba 2011, Brisbane 1974
How do organisms differ?
By how they obtain carbon and energy
Coriolis Effect
Causes moving air and water to deflect left in the southern hemisphere and right in the northern hemisphere due to Earth's hemispheres. Deflection is strongest at the poles and weaker toward the equator.
What are biotic components?
Cellular organisms and viruses
What role does climate play on distribution of ecosystems?
Climate (mostly water availability and temperature) influences the biotic components of ecosystems.
What is the difference between climate and weather?
Climate is an average, long-term pattern Weather is more spontaneous (i.e. rain during a short term drought)
What are biomes?
Climate zones that affect the biotic component, resulting in species that are more similar within a biome than between them
What are foodwebs?
Complex feeding relationships in an ecosystem (poorly represents reality)
What are heterotrophs?
Consumers that cannot fix inorganic carbon but rather capture it from organic molecules such as amino acids and sugars. Includes fungi, animals, insects, most bacteria and archaea
What are the four ways that uplift of air can occur?
Convection, cyclonic/convergence precipitation, frontal precipitation and orographic precipitation
What happens to equilibrate the differences in energy between latitudes?
Coriolis forces
What are the anthropogenic sources of arsenic?
Cu/Pb/Zn smelting, steel production, coal combustion, wood fuel, burning of forests/savannah/pasture, herbicides, wood preservatives, glass manufacture, waste incineration
What are abiotic components?
Dead organic matter, temperature, nutrients, salinity, pH, moisture, UV exposure etc.
What causes global warming or calling?
Disrupting the earth's energy balance
What are characteristics of Mediterranean/Marine regions?
Dry summers and wet winters Found on the west side of continents occur due to the STR moving pole-ward in summer (important in S coastal regions of WA, SA, Vic and TA
What are some examples of human activities being beneficial?
Dujiungyan irrigation system in china, 256 years ago supporting ~700000ha or ag land
What does this energy gradient/imbalance in energy influence?
Earth's atmospheric circulation patterns
What is the most influential periodic change in climate in Australia that occur once every few years?
El Nino Southern oscillation
How does energy loss limit trophic levels?
Energy losses constrain the amount of energy, biomass and individuals associated with each level
What are regulating ecosystem services in terms of water?
Flood control, erosion and sediment control, water purification
Hadley cells
Global convection cells where hot air rises at the ITCZ, cools, and falls around 30 degrees North and South
What are characteristics of moist subtropical regions?
Found on the eastern sides of continents large water surplus Influenced by the STR Winds flow over oceans, becoming moist and onto land
How does energy flow through an ecosystem?
From primary producers to consumers and some to decay. Energy from consumers then decays which leads to soil nutrients.
Net primary production (NPP)
GPP minus the energy respired (used for plant growth and maintenance)
What is net primary production?
GPP minus the energy used by producers to respire
What do climatic regions reflect?
Geographic position Proximity to water Altitude and the origin of air masses as a consequence of the global circulation system
What do the climatic zones reflect?
Geographic position (latitude) Proximity to oceans Altitude Origin of prevailing air-masses as a consequence of the global circulation system
Functional groups
Groups of functionally equivalent species that contribute to specific ecosystem functions. Eg, pollinators, herbivores, pollutant degraders, uranium reducers etc.
What causes the coriolis effect?
Hot air rises and begins to travels toward the poles, but deflection causes it to be churned and come down at 30 degrees North and South
What happens in a Hadley cell?
Hot, wet air rises and expands and cools as it rises, forming clouds where water condenses and causes precipitation. It tries to equilibrate by going to the poles as there is less energy there on average. As it goes, it will begin to cool, and descend as cool, dry air.
What is the reason for the monsoon in Australia?
In January, northeasterly moist winds bring wet maritime air because the ITCA has moved south, it stoped in july when the ITCZ moves north and southeasterly winds bring dry continental air
Where is precipitation most variable?
In the interior of the country
What is the reason for winter rain in southern Australia?
In winter the ITCZ, its Hadley cell and the sub-tropical ridge moves north, allowing cold air to be blown across southern Australia, displacing warm air upwards to cause precipitation
What is the vegetation (Kopen) method of classifying Australian climate zones based on?
It is based on the concept that native vegetation is the best expression of climate and classifies six major climate zones and 27 sub-groups: equatorial tropical subtropical desert grassland temperate
Why is central Australia arid?
It is below the subtropical high-pressure belt and is a distance from moisture sources.
What happens to the easterly trough in the summer months?
It moves toward the coast, causing a frontal precipitation (convective) and showers and thunderstorms to form
Why is biodiversity important?
It plays an important role in maintaining ecosystem functioning
What is the seasonal rainfall method of classifying Australian climate zones based on?
It uses the difference between summer and winter rainfall to identify six major zones: summer dominant rainfall summer uniform winter winter dominant rainfall arid
What do naturally occurring lakes in Australia include?
Lagoons and perched lakes (blue and brown lakes on north Stradbroke and lake Mackenzie on fraser island), fresh water lakes (lake awoonga) and salt lakes in SA and WA, man made lakes
What affects temperature?
Latitude Altitude Coastal v. continental areas
What are some examples of human activities repeatedly destroying productive land?
Mesopatamia - 6000 years ago dams and aqueducts were developed to irrigate a fertile floodplain in an arid climate. The result was salt accumulation
What are some environment policies?
National environment protection council act (1994), environment protection and biodiversity conservation act (1999), national greenhouse and energy reporting act (2007)
What are the main differences in temperature in Australia?
North and south are different and the main temperature fluctuations are in the continental regions. High altitude regions are low enough to sustain snow in most winters
What are the soil horizons?
O (Organic layer) A (topsoil/suface soil - surface minerals) B (subsoil/deeper layer - concentrations of clay, Al, Fe) C (parent material/degraded bedrock - unconsolidated, partially weathered parent rock) R - bedrock
What are heterotrophs?
Oganisms that cannot fix inorganic carbon and must obtain organic carbon molecules from their environments
What does the spreading of sunlight beams mean for areas of the earth?
On an annual basis, equatorial regions receive a surplus of energy whilst polar regions receive a defecit
What contributes to the fact that it is greener on the eastern side of the great dividing range?
Orographic precipitation
Why is the eastern coast of Australia more wet?
Orographic precipitation
What is the difference between the nitrogen and phosphorus cycles?
P is not gaseous, there is no biological pathways and the major source of P is weathering of mineral rocks
What are the persistent organic contaminants?
PCDDs (dioxins), PCDFs (furans), PCBs, DDT, chlordane, heptachlor, Aldrin, endrin, dieldrin, toxaphene, mirex, hexachlorobenzene
What are the most important forms of organisms in terms of primary production?
Photoautotrophs; responsible for the main entry of energy into ecosystems and supplying organic carbon to most heterotrophs
How do oceans transport energy?
Pole-ward moving currents on the western sides of oceans (east of land) transport warm water to cooler latitudes. Equator-ward moving currents on the eastern sides of oceans (west of land) transport cool water to warmer latitudes
Convection Precipitation
Precipitation commonly known as a thunderstorm; caused when the earth is heated and moisture rises up to form clouds then comes down as precipitation
Orographic precipitation
Precipitation that develops when warm, moist air cools and condenses as it rises against mountains
Frontal/Convergence/Cyclonic Precipitation
Precipitation which results when two air masses of different temperatures meet and the warm air is forced over the cooler air.
Why would precipitation remain uniform throughout the year?
Proximity to the intertropical convergence zone. Intense heating causes precipitation in clouds
What are some features of vertosols?
QLD state soil, common inland, volcanics and sedimentary rocks, calcareous and gypsiferous, often sodic
What can bedrock become?
R layer (rocky layer)
Albido
Rate at which heat is reflected back into atmosphere / how strongly an object reflects light from light source (sun)
What is reynold's number?**
Re = ud/v ( = velocityxdepth/kinematic viscosity). An Re of less than 500 indicates laminar flow, of more than 2000 indicates turbulent flow. Used to determine the proportion of turbulent vs laminar flow
Where is the coldest place in January?
Siberia (-50), Greenland (-40) and Canada parts
What affects the rate of degradation processes?
Soil type, climate, land use and landform
Where is the warmest place in January?
Southern Africa and inner Australia
What are characteristics of moist continental regions?
Strong winter and summers great temperature variation don't exist in the southern hemisphere (important in East N.A., Europe and Asia) characterised by warm, moist, tropical air in summers and cold air in winter
What are common software used in hydraulic modelling?
TUFLOW, MIKE 11, MIKE 21, HECRAS, INFOWORKS/ISIS
Where does most soc come from?
root growth, literfall, decaying material
What is the main influence of precipitation in the north?
The ITCZ
What causes latitudinal effects?
The angle of incidence with which incoming solar radiation hits the earth's surface
What is Earth's energy budget?
The balance of incoming short-wave and outgoing long-wave radiation, largely determines the climate
What do climate zones influence?
The biotic component of ecosystems
What drives weather patterns?
The global circulation system seeks to create an equilibrium between regions of surplus and deficit energy through the redistribution of heat, moisture and mass
What are ecosystem functions?
The habitats, properties and processes of ecosystems. They include all functional attributes of ecosystems, even those that are of no use to humans. Eg; decomposition, habitat/refuge for species, water storage
How does temperature affect wavelength?
The higher the temperature of the object, the shorter the wavelength emitted and the greater the amount of radiation
What happens to climate in july?
The northern hemisphere warms dramatically, southern hemisphere does not cool drastically. There is a strong maritime influence
what is potential evapotranspiration?
the amount of ET if water supply was unlimited
What are La Nina conditions?
The opposite of El Nino conditions, tradewinds strengthen and there is an intensification of walker circulation, the equatorial pacific is cooler than average. Results in increased rainfall in Australia and drought in South America
What are biophysical interactions?
The physical properties of Earth's environments have played an important role in the evolution of life, but are in turn influenced by life itself. Interactions between biological and physical aspects of the environment.
Functional redundancy
The presence of more than one species in a functional group. Some species will be dominant whilst others will remain in lower abundance, acting as reserves in case dominant species are unable to fulfil their purpose
What causes the Australian monsoon?
The presence of the ITCZ over Northern AU in summer
What components of an ecosystem give rise to its functional attributes?
The properties of an ecosystem and the activities of its consistuent populations
What is productivity?
The rate of generation of biomass in an ecosystem
Primary production
The rate of generation of biomass in an ecosystem, The amount of light energy converted to chemical energy (organic compounds) by autotrophs in an ecosystem during a given time period
What happens when a beam of sunlight is spread over a larger area?
The same amount of energy is distributed over a larger area, therefore the amount of energy per unit area will be lower
What are the main differences between surface characteristics of water and land?
The sun penetrates water and not land The heat capacity is greater in water than land Water takes longer to heat and cool Water mixes whilst land does not There is more evaporation over water than land (greater loss of latent heat).
Why does the ITCZ move north and south?
The tilt of Earth at a fixed angle. As earth rotates the sun, the hemispheres point more toward the sun at certain times, meaning the ITCZ changes to correspond with the region where the angle of incidence is 90 degrees.
What causes seasons?
The tilt of the earth relative to its position whilst rotating the sun
What are normal climate condtions (Walker circulation pattern)?
There is an upwelling of cold, nutrient-rich water off of the coast of Peru to support high productivity. Tradewinds drive the Humboldt current to the equator where the water warms +10 degrees by the time it reaches the West Pacific. The warm water leads to convective precipitation over Indonesia and northern Australia
What is precipitation dependent on?
There must be condensation nuclei (i.e. any small particle that can attract water to form a droplet), moist air and uplift to cool the air
If the earth did not rotate and the sun surrounded the planet, what would be the result?
There would be excessive heating at the equator which would result in air being raised and circulated to the poles where it would be cooled and return
Why will sea levels rise?
Thermal expansion (increased distance between molecules with temperatures) as well as melting ice caps and glaciers
What are ecosystem services?
These represent the benefits human populations derive, directly or indirectly from ecosystem functions
What is the purpose of specific gases in the atmosphere?
They absorb specific wavelengths of energy and contribute to the warming of the atmosphere
What happens when tradwinds meet?
They cancel out, creating a place called the doldrums
What were the aims of the 1994 COAG water reform?
To approve allocation of resources, balance of environmental and developmental needs, implementation of catchment approach for water resource management, inclusion of the full cost of water supply to water pricing, establishment of consistent water rights for property and trading structures, establishment of standard public consultation practices and educational programs in relation to water use and water reform
What are the 5 soil formation factors?
Topography, time, climate, parent material and organisms
How is the return interval of a flood calculated?
Tr = (n+1)/m, P = 1/Tr
How does descending air return to the equator?
Tradewinds (from south east and north east)
What are the three main precipitation patterns?
Uniform throughout the year (Singapore), maximum during summer (Harbin) and maximum during winter (Palermo)
How much energy is lost between trophic levels?
Up to 90%
climate variability
Variation in climate over temporal scales
What is a seasonal change in climate?
Variations in climate that change over time
How is water use efficiency calculated?
WUE = Y/ET (y = yield, et = evapotranspiration)
Why does proximity to water affect temperature?
Water has a greater heat capacity, there is mixing of cool and warm etc
What is warmer in the northern hemisphere in January?
Water rather than land
The doldrums
Where tradewinds cancel one another out. At the equator, where the two Hadley cells converge, the atmospheric condition is often gloomy and listless, reflecting the sultry air and variable breezes.
What is the major driving force of ocean circulation patterns?
Wind blowing over the surface of the water (tradewinds, westerlies). Ocean currents reflect the average wind patterns over a number of years
What is the insurance requirement on mining companies?
a 30 year mine requires a 1000 year storm immunity
What is weathering?
a breakdown, releasing nutrients
What is climate change?
a change in the state of the climate that can be identified (e.g. using statistical tests) by changes in the mean and/or the variability of its properties, and that persists for an extended period, typically decades or longer. It refers to any change in climate over time, whether as a result of natural variability or human activity
What is the food-water-energy nexus? -
a convergence of the main issues that humanity faces i.e. food security, water security and energy security all in the context of a rapidly changing global climate, increased competition due to climate change and growing population
What is north Atlantic oscillation?
a departure in pressure between Azores high and Iceland low every 5 or so years. When there are high values, they are associated with a stronger Jetstream, cold air is restricted to the northernmost regions, north west Europe is wet. Where there are low values, they are associated with weaker Jetstream, there are cold outbreaks in the US and NQ Europe is dry
What is freeboard?
a factor of safety usually expressed as a height above the adopted Defined Flood Level, may compensate for factors such as wave action and historical and monitoring uncertainties
what is laminar flow
a flow regime characterized by high momentum diffusion and low momentum convection
What would the murray river mouth flow be reduce to by 2030 without changes?
a further 24%
How is soil carbon measured?
a hole is dug, a core is collected, air dried in the lab and put through a series of sieves, dry combustion allows the amount of CO2 produced to be measured
What can happen if water pricing is inadequate?
a lack of water storage, extensive water use
What is the ribbon model?
a long, thin, rectangular shape, very limited application, works where the river has well defined banks, consistent width, small urban rivers, canals, irrigation ditches
What is a global climate model?
a model than incorporates terrestrial, marine and atmospheric components so that you can provide with data and it outputs a realistic estimation of temperature, precipitation changes etc and estimate human influences on change
Solubility pump
a physico-chemical process that transports dissolved inorganic carbon from the ocean's suface to its interior, driven by higher solibility in cold water & thermohaline circulation
What is point-source water?
a single, identifiable source of pollutants such as a pipe or drain (also pollutants contributed by tributaries to main body of water) including pipes, drains, factories, combined sewers
How much surface area does a spoon of soil have?
a square meter
What is pedon?
a unit of small area with one soil type
What is an artesian well?
a well that pumps itself because it is wedged between two layers of impervious rock, creating pressure
What types of factors have shaped our evolution as a species?
abiotic and biotic factors
How much soil nitrogen is available to plants?
about 2%
How much water is returned to the atmosphere through evapotranspiration?
about 90%
What are some characteristics of lakes?
about 90% of freshwater is in lakes, restricted outlets but sufficient flows to maintain lake, most commonly in areas previously dominated by glaciers, generally short term features
What are the affects of climate change on agriculture?
abrupt shifts in forestry and agriculture systems, higher temperatures detrimental to yield/production, possible increased growth and water demand from increased CO2, increased frequency of extreme events (dry, wet, cyclones), reduced water availability in already stressed areas, decreased rainfall in high latitudes/sub-tropical/temperate areas, production losses, restrictions on land use because of sea level rise, impacts on weeds, pests, disease and animal health
What are gravimetric lysimeters?
accurate short term, use load cell and measure weight differences
How can the use of pesticides be reduced?
adoption of integrated crop protection strategies, use of resistant and tolerant cultivators wherever possible, adoption of alternative control strategies, including biological control, rotations exploiting allelopathy and bio-fumigation, use of reduced dosages of chemicals, improved spray application technology, education to improve pest management, research into/adoption of disease warning services, greater resilience on pathogen identification before deciding to apply pesticides
Where do nitrous oxide emissions come from?
agricultural soils (application of N-fertilizers), biomass burning and cattle production
What is the biggest contributer to AU GHG emissions?
agriculture/forestry/fishing at 29.3%
How is ENSO measured?
air pressure difference above Tahiti and Darwin is measured, differences between which is known as the southern oscillation index (SOI) and indicates the onset of either El Nino or La Nina
What are other types of salinity?
dryland irrigation
What is storm tide?
also known as storm surge, large waves that occur when an additional surge is applied on top of the astronomical tide caused by meteorological conditions
What are the rules regarding xs in a hydraulic 1D model?
always left to right in direction of flow, always normal to the direction of flow, never intersects, should be created at every change in river geometry, no large changes, not necessarily a straight line, preserve as far as possible to the river length
In what form is nitrogen a major nutrient for plants?
ammonium and nitrate
What is the Kyoto protocol?
an agreement between many countries to cut GHG emissions first commitment was to cut by 5.2% from 1990 levels by 2012, then by 18% of 1990 levels by 2020. Countries meet their targets through national measures but the protocol offers international emissions trading (countries can sell carbon credits), clean development mechanisms (countries earn emissions reduction credits by establishing emission reduction projects in developing countries) and joint implementation (between nations)
What is drainage baisin?
an area of land that receives runoff
What is integrated pest management?
an effective and environmentally sensitive approach to pest management
What is water use efficiency?
the amount of biomass produced per unit of water
What are water delivery rights?
an irrigator's right to have water delivered by an irrigation infrastructure operator through the operator's water infrastructure network, can be traded within a delivery system
What is AEP?
annual exceedance probability, the likelihood of occurrence of a flood or storm tide of a given size or larger than any years, usually a percentage
How can flood frequency be analysed?
annual maxima series used to statistically derive the peak flow rate for a given time period, high incertitude, need a long historical record, different statistical tools give different results, make sure high event estimate not sensitive to low record event
How much of the world's population lives in areas where water is insecure?
around 80%
What is a diurnal change in climate?
as the earth spins, light & warm conditions occur during the day and cool & dark during the night
where is there maximum productivity?
at the equator
where is there low productivity?
at the sub tropical ridge (less solar input than ITCZ)
What is one reason why climate may change for several years?
atmospheric and oceanic circulation patterns sometimes change
How is nitrogen cycled?
atmospheric nitrogen is fixed industrially or through vegetation, animals eat the vegetation and deposit N back into soil through waste, denitrification releases N back into the atmosphere and some is lost through leaching
What are the rules of modelling?
avoid random numbers, a model is a caricature of reality, model needs to be calibrated against a range of recorded low and high events, validation follows against a range of events
Why can't gaseous nitrogen be used by plants and animals?
because the triple-bonded molecule N2 is too strongly bonded
What are regulating services?
benefits obtained from the regulation of ecosystem services (carbon sequestration and climate regulation, waste decomposition and detoxification, purification of water and air, crop pollination, pest and disease control)
Where do transfers occur in the carbon cycle?
between the land, ocean and atmosphere through decomposition, consumption, marine sediments, fossil fuels etc
What is BOD?
biochemical oxygen demand, a measure of the quantity of oxygen utilised by the decomposition of organic matter over a specified time frame (usually 5 days), standard measurement for waste water samples and is used to quantify the relatively decomposable organic matter content of wastewater, unit is mg O2/L
What is the relationship between depth and biomass?
biomass decreases with depth increase
What are the ways to increase a water supply at a given location?
build additional dams to increase storage capacity, bring surface water from elsewhere (canals/pipelines), access groundwater, desalinate saline water, reduce wastage of water/improve water efficiency, import food to reduce water usage
What impacts will there be on AU and NZ?
by 2020, significant loss of biodiversity is expected for ecologically rich sites, including the great barrier reed and QLD wet tropics. By 2030, water security problems are projected to intensify in S and E AU and in N NZ. By 2030, production from agriculture and forestry is projected to decline over much of S and E AU and over parts of E NZ, due to increased drought and fire. By 2050, ongoing coastal development and population growth in some areas of AU and NZ are projected to exacerbate risks from sea level rise and increases in the severity and frequency of storms and coastal flooding
How is irrigation management done?
by managing the amount of water applied and the method, water applied should equal water lost through evapotranspiration and transpiration take water added by precipitation
What are calcarosols?
calcareous throughout
What is continuous rainfall loss?
calculated such that total storm rainfall excess matches the gauged hydrograph volume
What pollutants are important in air contamination?
carbon dioxide nitrous oxide methane carbon monoxide particular matter sufur dioxide nitrogen dioxide lead and dioxins
What are pesticides?
carcinogens that mimic hormones and eliminate non-target organisms
What are the impacts of flow regulation by dams and weirs?
chance to flow path alter channel stability and loading, straightening of river courses reduces water channel width, sediment loading, irregularity of flow and flow velocity
What causes fertility decline?
changes in nutrient cycling patterns and biomass removal which results in nutrients being moved out
What is pacific decadal oscillation?
changes in sea-surface temperatures of the North pacific every 20-30 years, producing variations in overlying air pressure. In a warm phase, the north west of the USA is warmer and drier, and the South west is wetter. In a cool phase, the north west is very wet and the south west has drought.
What is the muskingum method?
channel routing - because of reach storage effects, there is attenuation and lagging of inflow hydrograph, peak outflow occurs after the time of intersection of the inflow and outflow hydrographs
What is biochar?
charcoal used for agricultural purposes, bioenergy wastes and agricultural wastes could be converted. It has a lot of surface area and negative charge and so can hold a lot of nutrients on the surface
What are soil properties that drive productivity?
chemical fertility and physical fertility (au soils are old, salty and infertile)
What are examples of diseases caused by biological water pollution?
cholera, enteritis, dysentery, typhoid, hepatitis, poliomyelitis, cryptosporidiosis, schistosomiasis, ancylostomiasis , cause approximately 3.5 million deaths worldwide, and >2million child deaths
What are the types of soil dating?
classical dating, radioactive decay
What affects SOC levels?
climate temperature moisture vegetation type soil texture and type of clay and oxides topography land use practices land use change rotation fallow management tillage stubble management fertilization irrigation time
What is food security threatened by?
climate change, water shortage, reduced availability of arable land, diversion of food crops to bio-economies
What are characteristics of dry tropical/subtropical regions?
climate is dominated by the STR but higher latitude larger temperature range arid and semi-arid and dominant landscapes in South Australia and NSW
What does the amount of carbon in soils depend on?
climate, temperature, precipitation
What are some features of rudosols?
coastal and inland, fluvial, Aeolian, sedimentary
What are the environmental impacts of using too much phosphorus?
eutrophication (large biomass of algae)
What are enhanced efficiency fertilizers?
coating fertilizers, chemical inhibitors
What is sediment pollution?
common in Australia due to erosion and dredging, reduces light penetration, reduces habitat for microorganisms, reduces populations of algae/aquatic plants and fish populations
What are some features of kandosols?
common, weathered, fertile, grazing and cropping
What are current sources of conflict?
competing demands between sectors, over exploitation, drought/flood, water pollution, lack of access
What are anticipated sources of conflict?
competing demands, over exploitation, drought/flood, water pollution, lack of access
What is turn over?
complete replenishment of an element in a pool
Why is methane so threatening?
concentrations have more than doubled in the last 100 years and it is 25x more effective as a greenhouse gas than CO2
What is annual maximum series?
consists of one value, the maximum peak flow from each year of record, the Peak Over Threshold series can also be used in specific circumstances
Why is river biota unstable in the long term?
constant major disturbances (flood, drought, climate, land use, land cover)
What are tributaries?
contributors to greater catchments
Who participates in water markets?
controlled by states/territories, users/owners (irrigators, farmers, rural water utilities, irrigation infrastructure operators, industry, urban water utilities and environmental groups), intermediaries (brokers, conveyancers, solicitors, banks, money lenders and valuers), researchers (environmentalists, scientists, economists, hydrologists), government (AU, state, local, trade approval authorities), public (investors, community groups, general public)
What are some characteristic of the murray darling basin?
covers 15% of the Australian landmass, discharge one of the smallest amongst major river systems, 0.4 mL/s, aar = 408 mm/yr but potential evapotranspiration is 4x greater than amount of rainfall
How can soil organic carbon loss be reduced or build organic carbon?
crop management (improved fertility, better rotation of crops, suppression of disease for higher yield, fallow elimination, irrigation) conservation tillage (retaining some stubble, reduced tillage, no tillage) pasture management (different rates of fertilizer, different grazing management, earthworm introduction, irrigation, grass species, legume introduction, sown pasture) organic amendments (animal manure, biosolids) land conversion (degraded cropland to pasture, bioenergy crop, agroforestry (?), biochar (?))
Where is the biggest surface carbon pool?
deep ocean
What is eolian deposition?
deposited by air
What is colluvial deposition?
deposited by gravity
What is till/moraine deposition?
deposited by ice
What is lacustrine deposition?
deposited by lakes
What is outwash deposition?
deposited by melted ice
What is marine deposition?
deposited by oceans
What is alluvial deposition?
deposited by rivers
What is illuviation?
deposition of soil material removed from one horizon to another in the soil
What results do flood studies give?
depth, level, velocity, hazard, impact on neighbouring properties, testing of options, economic analysis
How can the peak flow rate of a small catchment (<25km2 if rural, 5km2 if urban) be estimated using the rational method?
directly based on area, slope, runoff coefficient and rainfall intensity, Q = (C.I.A.)/3.6 (Q = peak flow rate in m3/s, C = runoff coefficient, A = area in km2, I = rainfall intensity)
What are negative impacts of dam construction?
displacement of people and wildlife, flooding of farmland/landscapes, loss of agricultural productivity, wildlife habitat and associated biodiversity, fragmentation of wildlife corridors, introduction of non-native fish species, either accidentally or deliberately for recreational fishing, and the consequent alteration of aquatic food webs, impeded fish migration and reproduction, changes hydraulic flow regime and water quality, alteration of siltation and salinity in river deltas
What are the impacts of seasonal flow reversal?
disruption of natural water cycle, inhibition of fish migration, reduced fish reproductive success, downstream aquatic habitats
What are the three types of carbon in the ocean?
dissolved organic carbon, dissolved inorganic carbon (98%), particulate organic carbon
What is DO?
dissolved oxygen, as BOD increases, DO increases because oxygen has limited solubility, unit is mg O2/L
How are environmental flows ensured?
diversion licenses (allow people to take and use a certain amount under specific conditions), stream flow management plans (specific how water is shared in areas with high demand for water and where environment is at risk), bulk entitlement agreements (place restrictions on how water is companies take and use water and quantity that must be maintained in the river), local management plans (set minimum flows needed in areas where stream flow management is not necessary)
What are organosols?
dominantly organic materials
What are examples of modified landscapes?
drained wetlands, monoculture crops, man-made structures (damn, irrigation systems)
What is the best type of irrigation?
drip, more specifically sub-surface drip
What are supporting services?
ecosystem services that are necessary for the production of all other ecosystem services (nutrient cycling and dispersal, seed dispersal and primary production)
What influence how we manage water?
environmental (Climate change, water quality and quantity) and social factors (population growth and urbanisation)
What stages has development of water resource use gone through?
establishment (post European settlement, state-based activity, focus solely on economic benefit, water use depended on land ownership), development (after federation in 1901, intense dam building and irrigation development, water conservation act of 1880, irrigation act of 1886, water act of 1905 and water act of 1912) and reform (post 1980, growing appreciation of resource limitations and failure of past management practices)
What were the outcomes of the 1994 COAG water reform?
establishment of water trading system, introduction of economic regulation, introduction of two part tariffs to signal water use, elimination of free water allowances (surface water), establishment of monitoring and management with respect to water quality and environmental values, possibly improved efficiency of water use and management
How is catchment water balance calculated?
estimated runoff or Precipitation - Evaporation = Rs + Rg + ∆S Rs = surface water runoff, Rg = groundwater runoff, ∆S = change in storage
what is evapotranspiration?
evapotranspiration is the total evaporation plus the total transpiration from a given area of land
How often does vegetation carbon turn over?
every 11 years
How often does marine biota carbon turn over?
every 2-3 weeks (thousands of years for deep ocean)
How often does atmospheric carbon turn over?
every 3-4 years
How often do El Nino conditions occur?
every 3-8 years
What is a flood?
excess water, greater input than is able to output. When the water depth of the chanel exceeds the height of bank
What is water required for in terms of energy?
extracting primary energy fuel, refining energy fuel, generating electric power
What is Q10?
factor by which reaction increases with every 10dC
Where does volatilization occur?
farms with livestock cropping on coarse, sandy soils, alkaline soils and soils with low organic matter
What are the best management practices regarding fertilizers?
fertilizers are applied to meet projected crop needs for both timing and amount and applied to the most effective area for crop uptake, irrigations are managed to minimize nutrient loss
How can issues arising from dams be managed?
fish ladders, fish ways and fish lifts, multi-level offtake towers/removal of drop boards to reduce temperature change, changing dam operation to better mimic natural water flow
What are typical requirements for flood management?
floor level about 100 year ARI, lot level above 50 year ARI, impact of development less than 1cm on neighbouring properties
What is the route of arsenic exposure?
from parent material deposited in alluvial sediments, mainly associated with Fe/Mn/Al oxides, mobilised by reductive dissolution of Mn/Fe oxides as released to solution, shallow aquifer concentrations in Bangladesh (50-215 ug/L As)
How did the great artesian basin form?
from uplift of the eastern seaboard, erosion and sedimentation resulted in alternating layers of sand and gravels, consolidation of which resulting in sandstone, forming the permeable layers of the basin
What are the sources of inorganic pollutants?
geological materials, mining and smelting activities, agriculture, wastewater treatment facilities, fossil fuel combustion, industrial activities, waste disposal, warfare, nuclear power generation and others
What is the greatest challenge for getting a reliable soil carbon measurement?
getting a good representative sample
What is the climate model prediction based on the GHG scenarios?
global surface temperatures increase 1.4-5.8 degrees between 1990-2100 the most warming will occur in northern north America and northern and central Asia there will be more precipitation but also more year-to-year variability decrease in snow and ice cover except in parts of east Antarctica global sea level rise by 0.18 to 0.59m
What are the effects of air contaminations?
global warming damage to human and environmental health
What are features of eutrophic aquatic systems?
high nutrient levels, poor light penetration, low dissolved O2, shallow water, high algal growth, low water clarity, silt or clay bottom, typically have an overgrowth of aquatic vegetation and high NPP
Why worry about water quality?
high quality drinking water is essential for human well-being, upstream activities greatly affect downstream quality
How is nitrogen distributed in the soil?
higher concentration at the surface, about 0.02-0.5% in A horizon in non-cultivated soils, 0.15% in cultivated soils, most is found in soil organic matter
What is HAT?
highest astronomical tide, the highest predicted tide that occurs when the sun and the mood are closest to the earth, aka the percean spring tide or king tide, a level that closely approximates HAT occurs twice a year
What are anthroposols?
human-made soils
What positive feedback results from melting ice?
ice albido (ice sheets and caps melt, less light is reflected and more absorbed resulting in increased warming) arctic methane (as areas of permanently frozen ground (permafrost) melts), stored methane is released, resulting in further warming) forest fires (decreased rainfall and increased drought, increase in biomass burning/emissions and further warming)
What are three components to developing a catchment management plan?
identify the target area, identify the environmental values of the catchment (including communities), set water quality goals for the management plan
What are the four pathways that nitrate can take?
immobilization, plant uptake, leaching, denitrification (gas)
What are the five pathways that ammonium can take?
immobilization/mineralization, mineral fixation, volatilization (gas), plant uptake nitrification
How can agricultural emissions be mitigated?
improved land management to increase soil carbon storage restoration of cultivated peaty soils and degraded lands improved rice cultivation technique to reduce CH4 emissions improved livestock and manure management to reduce CH4 emissions improved N fertilizer application methods to reduce N2O emissions dedicated energy crops to replace fossil fuels improved energy efficiency and improvements of crop yields
What are some benefits of measuring soil carbon?
improved productivity buffering capacity resilience to adverse events reducing erosion protection of water bodies
When was the ecologically sustainable development with respect to water resources reform initiated and by what?
in 1992 by the Australian Industry Commission report on water resources and water waste disposal and COAG reforms based on National Strategy for Ecologically Sustainable Development
What changes in precipitation patterns have occurred in Australia?
in October to april, the northern wet season has been wetter than usual, and in april to November, the southern wet season has been drier than usual
When does granite become alfisol?
in arid environments with limited leaching and high base status (sodium, calcium, magnesium), long time frame
How does water movement in rivers differ to lakes?
in rivers, water moves laterally whereas it moves vertically in lakes
Where is water velocity fastest?
in the middle and at surface because of least friction
What is soil carbon made of?
in the top 1m of soil, there is at least 2500 billion tonnes of carbon, 3x as much as in atmosphere and 4x more than vegetation, soil has organic and inorganic components, mainly focus is on organic carbon and inorganic carbon is not well understood
What are the common metal contaminants?
include Pb (used in pipes, paints and gasoline in past), Zn, Cu
How important is soil water availability in terms of SOC accumulation?
increased soil water availability or precipitation more important than temperature and in some cases eCO2 to regulate SOC accumulation
What are the inputs and outputs in a terrestrial system?
inputs organic matter, outputs erosion, soil CO2, respiration, DOC leaching, soil carbon pools and plant roots, microbes and soil organic carbon
What options are there for water resource conflict resolution?
integrated management of resources, planned allocation, regulatory, economic and information based instruments (incentives for water efficiency, flexible water allocation mechanisms, tariffs to signal water scarcity, coordinated expansion, improved wastewater treatment and reuse, restoration of floodplains/wetlands, improved water governance, reform subsidies, investment in education)
What is IFD?
intensity frequency duration used to analyse rainfall patterns
What is the total murray river mouth flow?
it has reduced to 61% and flow is stopped for 40% of the time, compared to only 1% pre-colonisation
How do emissions capping and trading work?
it is a market based approach to reducing emissions through incentives establishes an emission cap in Co2 equivalents entites are given a quota of carbon credits, if they emit more than the carbon credits that they own they buy more this trading scheme means that the polluter pays and the company selling carbon credits gets paid for the emissions they save
Why is ocean acidification a bad thing?
it is detrimental to calcifying organisms (many photosynthetic primary producers), their shells dissolve.
What is the ocean floor?
it is entirely composed of basalt lava flows (mafic material)
Why is nitrous oxide so threatening?
it is increasing two-fold higher than previously and is 280x more effective as a greenhouse gas than CO2
What is the significance of the hyporheic zone?
it is the stream sediment layers beneath surface water that are usually porous and permeable. Surface water can move into the zone through areas of downwelling, or return through areas of upwelling containing high levels of nutrients, important studies of nutrient dynamics
What is the role of clay in nitrogen fixation?
it releases ammonium into the soil
How does nitrogen change in the soil?
it starts as ammonium (NH4), changes into nitrite (NO2) and becomes nitrate (NO3)
Can Australia support 40-50 million people?
it will depend on increasing our efficiency in interacting with our environment. In the short term it is viable, but it is most likely not sustainable
Why does each nutrient have a different cycle?
its natural state/phase (gaseous, liquid, solid), its mobility
What are kandosols?
kandite clay minerals
How does water ideally move?
laminarly, assuming a smooth surface, ideal conditions and constant width and depth. Mean velocity measured at 0.6 x channel depth at centre
What are some forms of degradation?
land clearing loss of biodiversity imbalances causing invasive species waste soil and water pollution
What is the problem with coal seam gas?
large amounts of water and potential flow on effects from aquifers, generation of highly concentrated super saline brine, possible contamination of soil, aquifers, remaining uncertainty about long-term impacts
How much power does a cyclone release?
latent heat releases enough to power the entire planet for 70 days
what is solar exposure influenced by?
latitude cloud cover aerosols
what is evaporation dependent on?
latitude (insolation) temperature cloudiness wind speed humidity (rainfall and proximity to water)
What is the relationship between carbon concentration and soil depth?
less deeper
What limitations are there to flow regulation?
limits will be determined by the needs of downstream communities
Who requires a flood assessment plan and why?
local gvt (planning purposes, emergency management plan, risk management), mining companies (to maintain production, bund design, insurance), insurances (cost of premium), transport authorities (bridge/road/drainage/infrastructure design)
What are non-weighable lysimeters?
long term
What does modification of landscapes result in?
loss of biodiversity, overexploitation, introduced species, water pollution, soil degradation (compaction, erosion, nutrient depletion, acidification, salinization, depletion of organic matter)
What are features of oligotrophic aquatic systems?
low nutrient levels, good light penetration, high dissolved O2, deep waters, low algal growth, high water clarity, rock/gravel/sand bottom, typically low - no aquatic vegetation and low NPP
What are tropical cyclones?
low pressure systems that bring strong winds and intense convergence & uplift resulting in heavy rainfall. They form 10-20 degrees north and south of the equator because they need coriolis force to get them spinning and the coriolis forces deflect them after they begin moving west
Under what conditions does basalt become ferrosol?
low-lying position, lower temperature, low rainfall, medium time frame
What parts of the flow regime have ecological impacts?
magnitude, frequency, duration, timing and rate of change affects water quality, energy source, physical resources and biotic interactions
What are the ways of adapting to coastal hazards?
maintain status quo (forced retreat), accommodate, defend, retreat (planned retreat)
What are slow release fertilizers?
manure, organic fertilizers
What is polypedon?
many pedons go into one
What are the types of erosion processes?
mass wasting (soil creep or landslip which takes time and occurs when soil is wet, earthflows or landslide) water (dissolution, fluvial processes) ice (glaciation) wind
What evidence is there of climate change?
melting glaciers and sea ice declining snow depths (40% change in the last 40 years in AU alps) increase in coral bleaching and ocean acidification due to CO2 in atmosphere change in mating and migrating times of birds and other organisms significant changes in global precipitation and cloud cover poleward and altitudinal shifts of plants and animals
How often does rock and sediment carbon turn over?
millions of years
How long does trophic state progression (oligotrophic -> mesotrophic -> eutrophic) take?
millions of years, which may be reduced to a matter of years through artificial eutrophication
Where does most soil inorganic carbon come from?
mineral weathering and agricultural lime
What is secondary salinity?
mobilization of primary salinity, a change in the water balance caused by clearing vegetation, affects soil, plants and aquatic life, and some secondary issues
What are features of mesotrophic aquatic systems?
moderate nutrient levels (0.3-0.65 mg/L of nitrogen, 0.01-0.03 mg/L of phosphorus), moderate light penetration, moderate dissolved O2, some algal growth in summer, moderate - high water clarity, high diversity of flora and fauna, important habitat for macroinvertebrates and rare aquatic plants
What drives compaction?
moisture content of soils and size and type of machinery
With warmer temperatures, what can be expected?
more evaporation more precipitation more variability by location increased intensity of precipitation events particularly in tropics and high latitudes precipitation extremes will increase (floods, droughts) greater rainfall over ITCZ less rainfall at mid latitudes and dry tropics (more intense Hadley cell) Hadley cell extension pole-ward thereby drying out southern Europe and US
Why is leaching of nitrate a major issue?
nitrate is mobile in the soil
What are features of Australian rivers?
most are tropical to subtropical, high potential evaporation, wet-dry cycle (somewhat predictable, correlated with aboriginal calendar), frequent extreme events, recurring flooding = vegetative patterns in floodplains
What may elevated CO2 lead to?
net SOC accumulation especially in fast turnover pool but it may not alter rate of turnover of new carbon inputs
What is the composition of the atmosphere?
nitrogen composes 78% (largely inert, obtained from volcanoes and bacteria) oxygen 21% (chemically active (oxidation), increased by photosynthesis) carbon dioxide 0.035% argon 0.93%
What factors affect nitrate leaching from soils?
nitrogen management, land management, climate, irrigation management, economics, drainage volume, crop and soil type
Do we have enough water for 40-50 million people?
no, Australia is very arid. Advancements in technology to desalinate water may help. This is not sustainable if it involves fossil fuels
Does soil type change after development?
no, it takes too long to form
What are cultural services?
nonmaterial benefits people obtain from ecosystems through spiritual enrichment, cognitive development, reflection, recreation and aesthetic experiences (cultural, intellectual and spiritual inspiration, recreational practices and scientific discovery)
What is the general age trend of basalt flows?
older in north and younger in south
What can acidification of soils cause?
nutrient deficiencies and toxicity, mobilisation of metals, corrosion of infrastructure
What factors affect the nutrient cycle?
nutrient type, time, climate, soil type, topography, vegetation, human activity
What are the names of rock layers?
o layer (organic material, leaf litter, dead bodies, dark, carbon rich layer) a horizon (topsoil, nutrient rich, most plant life) b horizon (subsoil, mixture of topsoil and bedrock) c horizon (unconsolidated parent material) r horizon (bedrock)
What does boundary determination depend on?
objective, climate, topography, level of detail required
What are chromosols?
often brightly coloured
What are dermosols?
often with clay skins on ped faces
What are ferrosols?
often with high iron content
What is the limitation of phosphorus and nitrogen?
old soils are rich in nitrogen but poor in phosphorus, young soils are poor in nitrogen and rich in phosphorus
Where does water flow fastest as it travels around bends?
on the outside
How do we influence the environment?
our activities manipulate the environment
Why is nitrogen fertilizer efficiency reducing?
overapplication, inflation of costs, land size
What are 3rd order streams?
where 3 streams come together
What does subsurface water have to do with land formation?
particularly important where bedrock is soluble (I.e. limestone), more important in humid/wet landscapes (more water available), water initially collects in depressions resulting in sinkholes, groundwater movement results in caverns
What are water access entitlements?
perpetual/ongoing entitlement to exclusive access to a share of water from a specified consumptive pool, tradeable with land within a market boundary, volume can be varied based on the available amount of water
What are contaminants of emerging concern?
personal care products and pharmaceuticals, many mimic natural hormones (can disrupt an organism's endocrine system)
What are kurosols?
pertaining to clay increase
What is NPP?
photosynthesis production take respiration
What are the types of land degradation?
physical (erosion, mass movement, compaction) chemical (nutrient deficiency, fertility decline, salinity, acidification, contamination)
How is water quality assessed?
physical characteristics (temperature, Total Suspended Solids, turbidity, colour, odour), chemical characteristics (pH, Electrical Conductivity, Dissolved Oxygen, nutrient concentration, BOD, concentration of potential contaminants), microbiological characteristics (faecal coliform, harmful bacteria, viruses and protozoans, pathogens, some mycobacteria and helminths), biological characteristics (relative abundance of selected macroinvertebrates, fish and plants)
Under what conditions does basalt become vertisol?
poor drainage, silica concentration becomes high, limited oxidation
what are the two different types of evapotranspiration?
potential evapotranspiration and actual evapotranspiration
What are the sources of air contamination?
power generation (coal, gas, oil) transport agriculture electricity
What happens to the SOI under El Nino conditions?
pressure difference decreases causing weakened trade winds (or even reversed). SOI is less than or equal to -8. Associated with drought in Australia
What is PMF?
probable minimum flood, the maximum flood that's reasonably estimated to not be exceeded, derived from a pmp
What are provisioning services?
products obtained from ecosystems (food, crops, wild food and spices, water, minerals, pharmaceuticals, biochemical and industrial products, energy)
Who develops flood assessment plans and why?
property developers (seeking construction approval, need to comply to local gvt guidelines)
What considerations must be made for water resources sustainability?
quality and quantity of available water, intergenerational equity, varying levels of scale, multiple domains and numerous perspectives
What is turbidity?
quantity of sediment in water can be determined by measuring turbidity, or quantity of solid particles that are suspended in water, causing light rays shining through to scatter, makes water appear cloudy or even opaque, measured in nephelometric units (NTU), drinking water quality guidelines in AU dictate guideline value of aesthetically 5 NTU but <1 NTU for effective disinfection
What factors contribute to flooding?
rainfall (heavy/frequent), cyclone, tsunami, storm surge (and high tide), dam failure, topography, water infiltration, vegetative cover, surface retention, land use
What are the phases of landscape evolution?
recent tectonic landscapes (steep stream grades and rapid erosion) mature streams (gentle stream grades, slow erosion) peneplain (very low stream grades, nearly no erosion) base level change (gradient increased, higher erosion) landscape rejuvenation (steep stream grades, rapid erosion)
What is water used for?
recreation, transport, habitat, production, industrial processes, religious, aesthetic reasons
What are the risks of pesticides on humans?
reduced human sperm count, reduced flog population, problems during pregnancy
What mitigation options are there?
reducing CO2 emissions/carbon sequestration improved energy supply (renewable or nuclear) transport improvements (efficient vehicles etc) building (improved efficiency) industry (efficient equipment/energy recovery) agriculture (carbon sequestration, etc) forestry waste (CH4 recovery) human population
What is a hydraulic 1D model?
represents river flow as a line, cross sections (xs) representing the floodplain geometry at a regular interval
What are the three ways of landforms arising?
rifting (moving apart), subduction (moving together) and transform (breakdown, faults, lateral movements)
What is secchi depth?
sediment pollution or relative turbidity can be measured using a secchi disk in field studies, the depth at which the black and white plate is no longer visible is called the secchi depth, the current rates of sediment erosion in the lockyer valley are estimated to be 30x greater than pre-colonisation
What are some roles of soil carbon?
sequestration (mitigation option through storing of carbon in soil) soil health (productivity - biological, energy, nutrients, system resilience - physical, soil structure, water retention, thermal properties - chemical, pH buffer, complexes cations, binding agents)
What are the types of erosion?
sheet erosion, rill erosion, gully erosion (bigger rill erosion), tunnel erosion
What is a braided stream?
where sediments are accumulates then slows and deposits
What are vertosols?
shrink-swell clays
What are the values of water?
social values (self-interested/'their rights', earthy/utility/aesthetic, environmentalists/aesthetic/conservation, service-oriented/interested in right to use water/utility of water), environmental values, economic values, spiritual values
What is catina?
soil formation on slope
What is field capacity?
soil moisture at a point where capillary forces and gravity are in equilibrium
What is the phosphorus cycle?
soil phosphorus is taken up by plants and extracted by mines, there is runoff in rivers and streams and erosion from phosphate rocks that remove it from the soil. Dissolve into water and uptaken by algae and aquatic/marine animals
What are the drivers of primary production?
soil properties, what life is reliant on and climate
What contributes to the value of an ecosystem?
soils
What causes acidification?
sometimes biomass, it usually results from fertility decline and sometimes by nitrogen inputs
What are the features of integrated urban water management?***
source diversification, reducing demand on potable supply, enhancing urban amenity values, use of structural and non-structural methods to optimise outcomes, provision of localise and decentralised urban water services, cooperation between governments and utility sectors, avoidance of short-term, localised and single-sector based decisions, provision of sustainable water systems
How does mining and smelting release arsenic?
sources include tailings, emissions, smelter complex materials and residuals, acid mine drainage,
What are the two main types of hydrological flood estimation techniques?
statistical and deterministic
What are 1st order streams?
streams with no tributaries
How does a hydrological model work?
sub-catchments are characterised by slope, roughness, soil type, rainfall etc, routing in reservoir, routing through river channel etc
What does classical dating use?
superposition and fossil record (only gives relative ages)
Where is hydrology focussed in flood studies?
surface water
What are characteristics of wet equatorial regions?
surplus of annual water (rainfall often > 2500mm) warm year-round associated with rainforests more energy in general can be stored within ecosystem higher biodiversity
What are the drivers of change in Australian agriculture?
technological advances, consumer demands, environmental concerns, government policies
What are the three main ways of dividing the Australian climate zones?
temperature & humidity seasonal rainfall vegetation (Kopen classficiation system)
Why is carbon distribution different amongst ecosystems?
temperature and moisture are different and these affect plant type and growth and microbial processes
What is capacity?
the ability to carry debris at a given discharge
What are some key strengths of humans?
the ability to recognise patterns and use tools
What makes water change phase?
the absorption or release of energy
If we wanted to focus a study on river movement, what is the most appropriate boundary?***
the active channel
what is actual ET?
the actual ET given the amount of water available in a certain ecosystem
What happens to the SOI under normal conditions?
the air pressure above Tahiti is greater than Darwin (this is why wind moves to the west)
What are the world's biggest lakes?
the black sea, then lake superior
What are some important issues in nutrient cycling?
the boundary of the system, internal structures (# sub systems, dynamics between sub systems)
What is folding?
the compression of landmasses
What are the effects of soil degradation?
the contaminants can damage and completely alter ecosystems and reduce agricultural productivity
What is intial rainfall loss?
the depth of rainfall before runoff
What is a storm surge?
the difference between the high tide and the amount of water pushed in by storms
What is the origin of landforms?
the earth's crust as tectonic plates (8 to 40km thick) move on the asthenosphere constantly
What is base level flow?
the elevation at which water can flow (sea level lowest)
What are the benefits of a 2D model over a 1D?
the flow path does not need to be pre-determined and there is a more accurate determination of the extent, magnitude and direction of flood flows
What is global warming potential?
the global warming potential is a measure of the energy absorbed by various gases relative to CO2
What significant early reforms occurred?
the great artesian basin cooperative agreement (emerging concern about groundwater prompted scheme to cap bores in GAB and restore pressure, GAB rehabilitation program), temporary cap on surface water extractions from murray darling basin waterways (result of audit, limited water diverted for consumptive uses, cap made permanent for SA, VIC and NSW)
What are the soil organic carbon pools?
the humus pool, particulate pool and resistant pool
What is the great artesian basin?
the largest groundwater source in Australia, the largest artesian basin in the world, underlays about 22% of the continent, estimated storage capacity of 64,900 ML, annual discharge of 0.63 ML (50% natural, 50% pumping), two thirds of anthropogenic pumped water is wasted, would take 70,000 years to replenish
What thermohaline circulation changes will occur?
the melting of Greenland's icesheets may reduce the salinity of water in the Gulf Stream, this could weaken the thermohaline circulation and reduce pole-ward heat transport. NW Europe, Greenland NE Canada may chill for hundreds to thousands of years, some even think it may stimulate glaciation
What is nutrient pollution?
the most prevalent water quality problem worldwide, causes eutrophication, major sources include agricultural runoff, sewage, industrial effluents, atmospheric inputs because of burning of fossil fuels/bush fires
What is the longest river in Australia?
the murray river
What is water pollution?
the presence in water of harmful and objectionable material in sufficient concentrations to make it unfit for use
what does transpiration have to do with evaporation?
the presence of vegetation alters evaporation due to shade, albedo and the fact that plants absorb water through their roots. Water taken up through roots passes through the plant and can be lost by transpiration through the stomata
What happens to the SOI under La Nina conditions?
the pressure difference increases causing enhanced trade winds. The SOI is +8. Associated with flooding and cyclones in Australia
What are environmental flows?
the quality, quantity and timing of water flows required to maintain the components, processes and functions and resilience of aquatic ecosystems
What causes cyclones?
the release of latent heat - water in gaseous state in atmosphere becomes precipitation
What is elluviation?
the removal of soil material in suspension from a layer of soil
What are shield volvanoes?
the result of hot spots as plates move
What models can be applied to river systems?
the ribbon model
What are native title rights?
the right of specified people to use water for a range of personal, domestic and non-commercial purposes, cannot be traded
What is water trading?
the right to use water resources, the objective is to equitably distribute resources for current and future generations, social and environmental demands by using market system as a tool
What are irrigation rights?
the same as water delivery rights, with the difference that irrigation rights can be converted into a water access entitlement
What are water allocations?
the specified volume of water allocated to water access entitlements in a given season, seasonally-based water access, can be traded without land, generally expressed as a percentage of total water access over a certain time
What is a 50 year flood?
the statistical probability of the recurrence of a flood of that magnitude
What is rifting?
the stretching of continental land masses, the formation of a rift valley and volcanic activity. The ocean moves into a widening gap and basalt lava forms the sea floor resulting in central ocean expansion
What is the water table?
the top of the saturated zone, can move up or down
What is gross primary production?
the total amount of solar energy captured by photosynthesis in producers in a given time period
What is urban sprawl?
the uncontrolled spread of urban development into neighbouring regions
What is the continental crust?
the upper zone is of felsic material (high in Si, eg granite lower density), lower zone of mafic material (high in Fe, Mg, i.e. basalt, gabro high density)
What can soil organic carbon be broken into?
the various biological, physical and chemical functions, both living and non-living in the environment
How is above and below ground carbon linked?
there are many different forms, photosynthesis fixes carbon into vegetation, which is eaten by animals, who respire it back into the atmosphere and release it into the soil with excrement and when they die, literfall and root exudation releases carbon into the soil, microbial and root respiration releases it into the atmosphere, leaching and erosion releases it into the hydrosphere
Why does urbanization cause more discharge?
there are more impervious surfaces and shorter lag to peak
What are the sources of organic contaminants?
there are more than 20,000 organic contaminants sourced from chemical industry (organic micropollutants), spillages/leaks etc (e.g. leakage from underground storage tanks), gasworks, electrical industries etc., derelict industrial sites, accidental releases, offsite transport of pesticides, leachates/runoff from biosolids, industrial effluents (dioxins, furans), waste disposal (landfill, leachates, wastewater effluents)
How has snow depth changed at spencer's creek since the 1960s?
there has been a 40% decrease
What happens in chemical deposition landscapes?
there is a movement of iron (or silica) in groundwater, evaporation causes precipitation, cementation occurs which causes erosion resistance and landscape inversion
What are the drawbacks of dams?
they affect the movement of fish, downstream flooding reduced
How do GCMs show humans have influenced climate change?
they will only replicate current conditions when human inputs of greenhouse gases have been included
how much water is needed to irrigate for maximum growth/crop yield
this can be found by subtracting the actual ET from the potential ET
What are the types of rainfall measurement stations?
tipping buckets, daily pluviographs, 3hr data
What was the aim of the national water initiative?
to achieve national compatibility in the markets, regulatory and planning schemes to achieve sustainable management of surface and ground water, clear water access entitlements, transparent planning, provision of environmental outcomes, sustainable water extractions (yield), open trading in water market, clear risk assessment, water accounting, facilitating water use efficiency, future adjustment, connect surface and groundwater resources
How does topography affect input and output?
top of slope has low horizontal input, more horizontal output. Bottom of slope has higher vertical output, moderate/high horizontal input
What is relief and what affects it?
topography, affected by position of slope, residual material (summit to shoulder area), colluvial materials (backslope to toeslope regions), alluvial materials (end of toeslope or floodplain)
What variables affect water movement to streams?
topography, soil type, contour curvature, land cover, patterns of precipitation and intensity, land use
What is GPP?
total production by photosynthesis
What are the types of hydraulic modelling?
transient or steady rate, sub-critical/super-critical flow, implicit vs explicit solver, 1D (river model as line and cross section normal to direction of flow), 2D (ground model as square), 1D-2D combination
What is thermal water pollution?
typically occurs where heated wastewater is released to an aquatic environment, common causes include water used for cooling in power, manufacturing and industrial plants, deforestation causing direct exposure of water bodies to sunlight, runoff from paved surfaces, underwater volcanoes and geothermal activity, can also include cold water released into warmer body
What are the aspects of a flood study?
typically two levels of analysis - hydrologic (quantify the relationship between rainfall and runoff), hydraulic (used to model the detailed behaviour of water over a more specific area)
What are characteristics of Australian rivers?
uneven rainfall, extreme rain events, affect water storage design dryland rivers in desert areas
What is common law/unrestricted access?
unlimited access to groundwater under a property (carries to today), backyard bores
Where is the second biggest surface carbon pool?
vegetation and soil
What is the significance of the riparian zone?
vegetation may be connected to water-saturated zones (parafluvial/hyporheic) via root system
What affects discharge?***
velocity, slope, depth, cross sectional area
What are characteristics of high latitudes (tundra, arctic, Antarctic)?
very low temperatures very little precipitation no true summer air is descending on the pole (dry and cold) which cool as it hits the surface, behaving like a liquid and flowing off of the polar cap, increasing in speed (causing intense winds). This air is funnelled through the peaks of the trans-Antarctic mountains
What are natural sources of arsenic?
volcanoes, low-temperature volatilisation, wind erosion, forest fires, sea spray
How does positive feedback occur in cyclone?
warm, moist air rises, and expands, cools and condences as it does. Condensation releases latent heat into the storm. Warmer air rises faster driving the inward spiral, and so on
What is energy required for?
waste water treatment, treating water, extract water, distribute water, collect water
What are the different types of water rights in Australia?
water access entitlements, water allocations, stock and domestic rights, riparian rights, water delivery rights, irrigation rights, native title rights
What climatic factors drive productivity?
water availability is the key determinant of productivity in Australia, temperature, sunlight
What is overland flow?
water flows over land, some will be lost through evaporation and evapotranspiration, some will infiltrate soil, begins when capacity of infiltration is exceeded, results in erosion
What is the global hydrologic cycle?
water in the ocean is evaporated, either forms clouds and be returned to ocean or condenses and fall as precipitation over a land mass, surface runoff into water bodies or ocean or infiltrating earth occurs
What is a cone of depression?
water is drawn down when more water is being drawn out of the table faster than it can move laterally
How is flow measured?
water levels are measured at specific stations and a rating curve is used to associate a flow estimate to a recorded level, can be quite high uncertainty (+- 20%)
What are provisioning ecosystem services in terms of water?
water supply, storage, food/wood/fuel production, biodiversity
What is embodied water?
water that goes into producing food
What is throughflow?
water that keeps moving through the saturated zone
What negative feedback results from melting ice?
water vapour (more evaporation, more cloud, more reflection of sunlight resulting in cooling)
How does the environment influence us?
water, soil and climate influence each other and dictate our lives
What are tenosols?
weak soil development
What is the process of coal seam gas production?
wells are drilled and water is released, reducing the pressure on the gas which is then collected as it vaporises. Hydraulic fracturing is sometimes used (water injected at high pressure to break up coal), increases the rate of release
What are hydrosols?
wet soils
What has to be considered when determining flows?
what is going on in a given area and also downstream, connectivity along river, between river and riparian zone and associated ecosystems
When do deltas form?
when sediment is deposited faster than it is lost, results in very fertile soils
What are 2nd order streams?
where 2 streams come together