Glossary

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

A

• acid sulfate soils: low-lying clays and sands near coastal or inland waters that contain sulfur-bearing compounds at concentrations above 0.05% in clays and 0.01% in sands, which produce sulfuric acid when drained or exposed to air, affecting surrounding waters and ecosystems
• adaptation: decisions and actions to manage risks and capture potential opportunities in response to climate change
• air toxics: gaseous, aerosol or particulate contaminants present in ambient air in trace amounts with characteristics (toxicity, persistence) which make them a hazard to human health, and plant and animal life
• algal bloom: dense and visible growth of algae in a waterbody, resulting from proliferation caused by increased nutrients (such as phosphorus) and/or warm weather, generally resulting in reduced oxygen availability in the water for other organisms and possibly release of toxic substances
• alluvium: clay, silt, sand, gravel or similar material deposited by running water, especially during recent geological time
• anthropogenic: produced or caused by human activity
• aquaculture: cultivation for commercial purposes of aquatic organisms including fish, molluscs and plants in fresh or salt water
• aquifer: rocks and porous sediments which hold and yield groundwater
• atmosphere: the mixture of gases surrounding a planet, such as the Earth
• Australian Carbon Credit Units (ACCUs): a tradable financial product, which represents a reduction in greenhouse gas emissions achieved through activities that store carbon or reduce emissions, such as reforestation, soil carbon management, and energy efficiency improvements. Each ACCU represents one metric tonne of carbon dioxide equivalent (CO₂-e) emissions avoided or removed from the atmosphere

B

• ballast water: water carried in tanks to maintain stability when a ship is lightly loaded and normally discharged to the sea when the ship is loaded with cargo
• bioaccumulation: the accumulation in an organism of substances such as pesticides or other chemicals, which occurs when the organism absorbs a substance known to have toxic effects at a faster rate than the substance is lost
• biodiversity: the variety of all life forms: the different plants, animals and microorganisms, the genes they contain and the ecosystems they form
• biomass: the total mass of living material occupying a specific part, or the whole of, an ecosystem at a given time
• bioregion: relatively large areas characterised by similar broad, landscape-scale natural features and environmental processes that influence the functions of ecosystems – these landscape patterns are linked to fauna and flora assemblages and processes at the ecosystem scale, providing a useful means for simplifying and reporting on more complex patterns of biodiversity
• Biosecurity: protecting the economy, environment and community from the negative impacts of pests, weeds and diseases
• biota: collectively, the plants, microorganisms and animals of a region
• black water: occurs naturally due to the breakdown of leaf litter, inundated crops and other vegetation which results in the release of tannins and lignin causing water discolouration and is associated with low dissolved oxygen levels
• Black Summer bushfires: one of the most intense and catastrophic fire seasons occurred in Australia from late 2019 to early 2020
• bulk water: water harvested, stored and transported before being provided to retail water supply systems
• bycatch: species taken incidentally in a fishery along with the target species; often discarded

C

• calcitic: in marine organisms, skeletons, shells, structures etc. that are based on calcium carbonate (calcite)
• carbon credits: certificates representing the reduction or removal of one tonne of carbon dioxide or equivalent greenhouse gases from the atmosphere. They are created through projects that reduce emissions, such as renewable energy, and can be bought and sold to help meet emission reduction targets. Projects earn one carbon credit for every tonne of carbon dioxide or carbon dioxide equivalent (CO₂-e) stored or avoided by a project
• carbon cycle: the process that moves carbon between atmosphere, soils, living creates, the ocean, and human sources
• carbon dioxide equivalent (CO₂-e): a metric measure used to compare the global warming potential (GWP) of various greenhouse gases relative to the concentration of CO₂ (which is defined as having a GWP of 1). For example, methane is 25 times more effective than CO₂ at heating the atmosphere and therefore has a GWP of 25; thus five tonnes of methane is equivalent to 5 × 25 = 125 tonnes of CO₂
• Carbon offsets: a series of activities aimed at reducing greenhouse gas emissions, for example investing in renewable energy, to compensate for emissions generated elsewhere in order to help achieve carbon neutrality
• carbon sink: natural processes that absorb carbon dioxide as part of the carbon cycle, including land, soils, plants, and oceans
• chain volume measures: volumes of economic activity or production that are weighted annually to remove the effect of changing prices and linked (or chained), to enable description and comparison of changes in levels of production or activity over time, particularly relevant where the prices of resources (like oil) or commodities (like computers) are subject to rapid change or variability
• circular economy: keeping products and materials in use for as long as possible, for example by designing products so that all components can be recycled or re-used
• climate change adaptation: the process of adjusting systems, practices, and policies to minimise the negative impacts of climate change
• climate change mitigation: any efforts to reduce or prevent the emission of greenhouse gases, including transitioning to renewable energy
• climate variation/climate variability: long-term changes in the patterns of average weather of a region or the Earth as a whole due to natural cycles of variability
• Climdex: a set of climate indices used for climate change detection and attribution studies, climate model evaluation, and operational monitoring of extreme climatic events
• Combined Drought Indicator: a tool used to assess the severity of drought conditions by combining multiple climate and soil moisture indicators, including rainfall, soil moisture, plant growth, and drought trends
• Commercial sector: the commercial sector includes a wide range of sub-sectors including services, construction, retail & wholesale, health, education, public administration, recreation & entertainment, communications, finance, and property
• connectivity: the degree to which partially cleared landscapes facilitate animal or plant movement or spread and ecological flows (compared to natural flows)
• Country: the term used to describe both the land and waters, including the sea, to which groups of Aboriginal people have a cultural connection
• critically endangered species: species (or population or ecological community) facing an extremely high risk of extinction in NSW in the immediate future

D

• Decarbonise: to reduce greenhouse gas emissions
• Decoupling: the process of separating economic growth from environmental degradation, so that increases in economic activity do not lead to proportional increases in resource use or environmental harm
• derived grasslands: areas of native grasses that were previously forest or woodlands
• deseasonalised: the process of removing seasonal effects from data to reveal underlying trends or patterns, allowing for the analysis of long-term trends without the influence of regular seasonal variations
• diffuse source: (pollution of waterways) where contaminants from a dispersed range of urban or rural land use activities pollute waterways, mainly resulting from rainfall runoff after storms
• Discrete Aboriginal Communities: are former Aboriginal reserves or missions transferred from the NSW Government to Local Aboriginal Land Councils under the NSW Aboriginal Land Rights Act 1983. There are currently 61 Discrete Aboriginal Communities across NSW and many have high levels of legacy contamination
• disturbance: (ecology) any process or event which disrupts ecosystem structure and resource availability
• diversion: volume of water taken from a stream or aquifer on a sustained basis to supply water for rural, urban and industrial uses; includes diversions undertaken by a water authority, private company or a group of individuals authorised to act as a water supply authority

E

• ecological carrying capacity: the maximum population size of a species that an environment can sustain indefinitely without degrading the natural resources and ecosystem services on which that population depends
• ecological community: an aggregation of organisms characterised by a distinctive combination of two or more species
• ecosystem processes: the numerous interactions between different components (both living and non-living) of an ecosystem that support the biological elements of the system, including the storage and cycling of energy, nutrients and minerals; predation and competition; disturbance; weathering; and succession
• ecosystem services: any biophysical functions provided by an ecosystem, such as the provision of clean air and water, the maintenance of soil fertility and the removal of wastes, that benefit humankind
• El Niño – Southern Oscillation (ENSO): a natural oscillation in the state of the ocean–atmosphere system that leads to substantial changes in atmospheric circulation throughout the Asia–Pacific region and generally drier conditions in eastern Australia
• electrical conductivity: a measure of charged particles in water used to estimate salinity, measured in microSiemens per centimetre (µS/cm)
• electrolysis: a chemical process that uses an electric current to drive a non-spontaneous chemical reaction
• embodied carbon: the total amount of carbon dioxide (CO₂) emissions associated with the entire lifecycle of a product, material, or building
• emissions trading: a scheme to provide for market-based allocation of discharge opportunities; the environmental regulator first determines total acceptable emissions and then divides this total into tradable units (often called credits or permits); these units are then allocated to scheme participants
• endangered species: a species (or population or ecological community) facing a very high risk of extinction in NSW in the near future, but not considered to be critically endangered
• endemic: species that are native to a specific area and not found anywhere else
• energy intensity: a measure of the energy efficiency of an economy, it is typically calculated as energy use per unit of gross domestic product (GDP)
• environmental flows: flows of water (by volume and season) necessary to maintain aquatic biota and ecosystem processes
• ephemeral plants: plants with a short life cycle – either perennial plants that produce new growth in a short seasonal cycle or plants that emerge and grow in response to short wet periods in arid climates
• estuary: the part of the river mouth or lower course of a river in which its current meets the sea’s tides, and is subject to the effects of both, and where fresh water and salt water are mixed. A transition zone between riverine and marine environments
• eutrophication: the over-enrichment of a body of water with nutrients, primarily nitrogen and phosphorus, resulting in excessive growth of some plants and algae and the subsequent depletion of dissolved oxygen
• evapotranspiration: the term used to describe the sum of all processes by which water moves from an area to the atmosphere via evaporation and transpiration
• e-waste: used (‘end-of-life’) electrical and electronic equipment, commonly composed of many component materials that are difficult and expensive to separate in order for them to be reused. Many of these materials, such as copper and gold, are valuable non-renewable resources; others, such as heavy metals, carbon black and brominated-flame retardants, are hazardous
• extinct species: species that has not been recorded in its known or expected habitat in NSW over a time-frame appropriate to its life cycle and form and is therefore presumed to be extinct
• extraction: taking water from a waterbody or aquifer for human use (also called abstraction)

F

• faecal coliforms: a group of bacteria found in animal (including human) intestines and used as an indicator of the sanitary quality of water
• faecal enterococci: a group of bacteria found in animal (including human) intestines and used as an indicator of the sanitary quality of water
• fire regime: the typical frequency, intensity, duration, aerial extent, and seasonality of wildfire disturbance in a particular ecosystem
• fire weather: the atmospheric conditions that influence the size, intensity, speed and predictability of wildfires
• fish kill: any sudden and unexpected mass mortality of wild or cultured fish due to water contamination or natural causes of oxygen deletion (algal blooms or back water)
• fishway: a structure placed on or around a constructed barrier (such as a dam or weir) to give fish the opportunity to migrate, also known as a fish ladder or fish pass
• food web: a network describing the feeding interactions of the species in an area
• Forcings (atmospheric forcings, Natural forcing, anthropogenic forcing – see ): factors that drive changes in the Earth's climate system, influencing long-term changes in climate patterns
• Forest fire danger index (FFDI): a numerical scale is used to assess the potential for fire ignition and spread based on weather conditions, including temperature, humidity, wind speed, and rainfall
• fossil fuels: any of a class of carbon- or hydrocarbon-containing materials of biological origin occurring within Earth’s crust that can be used as a source of energy
• fragmentation: the division of continuous habitat by the clearing (or disturbance) of native vegetation for human land-use activities, which isolates the remnant patches of natural vegetation and the species within them, and limits the passage of organisms and genetic flow between populations
• fugitive emissions: releases of gases or vapours from mines or industrial equipment due to unintended or irregular occurrences (e.g. leaks)

G

• Greater Capital City Statistical Area (GCCSA): is defined by the Australian Bureau of Statistics as representing the socioeconomic extent of each of the eight State and Territory Capital cities. GCCSAs contain not only the urban area of the city but also areas of non-urban land where much of the population has strong links to the capital city, through for example, commuting to work.
• Greater Metropolitan Region (GMR): the GMR comprises all local government areas in Sydney, Illawarra, Central Coast, Lower Hunter and the Upper Hunter regions
• Greater Sydney: extends from the Hawkesbury River in the north to the Royal National Park in the south; towards the west, the region includes the Blue Mountains, Wollondilly and Hawkesbury local government areas
• green hydrogen: hydrogen produced by electrolysis of water using renewable energy, which generates no carbon emissions in the process
• greenhouse effect: refers to the blanketing effect of atmospheric greenhouse gases on the Earth, which absorb and re-radiate a proportion of the sun’s energy back to the Earth. Without this blanketing effect, the Earth would be about 33 degrees Celsius cooler. The greenhouse effect has been enhanced by the increased concentrations of greenhouse gases in the atmosphere arising from human activities such as burning fossil fuels and deforestation
• greenhouse gases: atmospheric gases, including carbon dioxide, methane, chlorofluorocarbons, nitrous oxide, ozone and water vapour, which trap heat reflected from the Earth’s surface
• Gross State Product (GSP): an economic indicator, referring to the total value of goods and services produced within a state during a specific period
• groundwater: the water beneath the earth’s surface that has filtered down to the zone where it is captured and the sediments or rocks are fully saturated
• groundwater-dependent ecosystem (GDE): ecosystems where the species composition or natural functions depend on the availability of groundwater
• growth form: (vegetation) the general morphology or form of a plant type e.g. tree, shrub, herb, grass etc.

H

• Heatwaves: the maximum and the minimum temperatures are unusually hot over a three-day period in a specific location
• High resolution: the level of detail or clarity in an image, map, or data set, typically characterised by a large number of pixels or data points
• Hot days: days with maximum temperatures exceeding 35 degrees Celsius
• hydrogeology: relates to the distribution and movement of groundwater in soil and rocks
• humidity: a measurement of how much water there is in the air

I

• industrial sector: the Industrial Sector includes the agriculture, mining and manufacturing sectors
• inter-annual: variations or changes that occur between two or more years
• Intergovernmental Panel on Climate Change (IPCC): an intergovernmental body of the United Nations that assesses the science related to climate change
• invasive species: a general term for plants, animals, weeds or other organisms such as pathogens that are introduced to places outside their natural range, where they negatively affect local ecosystems and species
• invertebrates: animals without backbones, such as insects, worms, snails, mussels, prawns and cuttlefish

K

• key threatening process (KTP): under the Biodiversity Conservation Act 2016, a process that significantly threatens, or may have the capability to significantly threaten, the survival or evolutionary development of native species, populations or ecological communities

L

• Land use, land use change and forestry (LULUCF): a greenhouse gas inventory sector that covers emissions and removals of greenhouse gases resulting from direct human-induced land use
• long-term average annual extraction limit (LTAAEL): the average level of groundwater that can be extracted annually from an aquifer for extraction to be sustainable over the longer term
• longwall mining: the main method of underground coal mining in Australia, it involves progressively shaving slices of coal from a longwall face under the protection of hydraulic roof supports. The coal is removed on a conveyer and as the machinery and roof supports move forward the roof and overlying rock collapse into the void left behind

M

• macroinvertebrates: invertebrates visible to the naked eye, having a body length exceeding 1 millimetre
• Mean: the average, which is a measure of central tendency in a set of numbers
• Millennium Drought: A severe drought event recorded in southeastern Australia from 2001 to 2009
• mitigation: decisions and actions to reduce the severity of climate change impacts. Usually referring to reducing the levels of greenhouse gas emissions
• montane: of or inhabiting mountainous country
• mosaic: (vegetation) a combination of distinct vegetation types within a spatial unit that often cannot be discriminated by the mapping techniques employed

N

• The NSW and Australian Regional Climate Modelling (NARCliM): the NSW Government's trusted source for regional climate projections data and associated information for NSW
• national energy market (NSW): the National Electricity Market includes Queensland, NSW, the ACT, South Australia, Victoria, and Tasmania
• non woody vegetation: for vegetation monitoring using Landsat MSS satellite sensors, vegetation formations that are less than two metres high or with less than 20% canopy cover (mainly grasslands, arid shrublands and woodlands)
• NOx: a generic term for a combination of the gases nitric oxide (NO) and nitrogen dioxide (NO₂); other oxides of nitrogen (e.g. nitrous oxide, N₂O are usually not regarded as a component of NOx)

P

• pathogen: a disease-causing organism
• per capita: also referred to as per person or per head. This term is used when a unit of measure has been calculated as an amount or rate against the number of persons in the community
• pest animal: an animal (usually non-native) having, or with potential to have, adverse environmental, economic, or social impacts
• phreatic aquifer: the body of groundwater closest to the surface, the upper boundary of which corresponds to the water table
• phreatophytic vegetation: deep-rooted plants that obtain a significant portion of the water they need from below the water table
• planned environmental water: water committed to the environment by water rules in water sharing plans
• point source: (pollution) a source of pollution that can be pinpointed, such as a pipe outlet or chimney stack (see also diffuse source)
• potable: water safe enough for drinking and food preparation
• productivity: (biology) the rate of accumulation of organic material in an ecosystem
• projected/projection: an estimate or forecast of a future situation based on a study of present trends
• pyrocumulonimbus storms: a type of thunderstorm that forms as a result of intense heat generated by wildfires

R

• recharge: the process whereby surface water from rain, irrigation or streams infiltrates into groundwater; the amount of water added to or absorbed into a groundwater system; or groundwater that feeds surface waters (also known as baseflow)
• regulated rivers: (water resources) those rivers proclaimed under the Water Act 1912 as having their flows controlled by the major dams where ‘regulated’ means that flows along the length of these rivers are controlled by releases from major dams to meet the needs of licensed users; (hydrology) rivers affected by major dams, weirs, canalisation and water transfers
• remnant: (ecology) a small, fragmented portion of vegetation that once covered a broader area before the surrounding vegetation was cleared
• remote sensing: a means of acquiring information using airborne equipment and techniques to determine the characteristics of an area, commonly using satellite imagery or systematic photography from aircraft
• renewable energy target: a policy target to encourage the development of new renewable energy generation
• riparian: occurring on or adjacent to a river, stream or other waterway
• riparian zone: the riparian zone is the interface between land and creeks, streams, rivers and wetlands. It includes the immediate vicinity of the stream, which consists of the bed, banks and adjacent land including floodplains, which carry large floods as well as the emergent aquatic plants growing at the edge of the waterway channel and the ground cover plants, shrubs and trees within the riparian zone
• runoff: water from rain or snow (and the substances it carries) which flows off the surface of the land into rivers, catchments or drainage systems

S

• sclerophyll: vegetation with hard leaves and short internodes, adapted to dry conditions and often low levels of soil phosphorus, usually with an over-storey of eucalypts
• sequestration: carbon sequestration is the general term used for the capture and long-term storage of carbon dioxide. Capture can occur at the point of emission (e.g. from power plants) or through natural processes (such as photosynthesis), which remove carbon dioxide from the earth's atmosphere
• simulation: the imitation or modelling of a real-world process, system, or phenomenon to study its behaviour under different conditions
• stationary energy: stationary energy is a term used in the estimation of greenhouse gas emissions. It includes emissions arising from: electricity and heat production, petroleum refining, solid fuel manufacture, manufacturing and construction industries, and fugitive emissions from fuels
• suspended solids: any solid substances present in water in an undissolved state, usually contributing directly to turbidity (of physical origin usually – fine clay and silt, sometimes also of biological origin – plant material or animal waste)
• Sydney metropolitan area: comprises 41 local government areas – Ashfield, Auburn, Bankstown, Blacktown, Blue Mountains, Botany, Burwood, Canada Bay, Camden, Campbelltown, Canterbury, Fairfield, Hawkesbury, Holroyd, Hornsby, Hunters Hill, Hurstville, Kogarah, Ku–Ring–Gai, Lane Cove, Leichhardt, Liverpool, Manly, Marrickville, Mosman, North Sydney, Parramatta, Penrith, Pittwater, Randwick, Rockdale, Ryde, Strathfield, Sutherland, Sydney, The Hills, Warringah, Waverley, Willoughby, Wollondilly and Woollahra; does not include Gosford and Wyong local government areas

T

• temperature anomaly: the difference between the observed temperature for a specific location or period and a reference or average temperature over a defined baseline period
• thermal expansion: the increase in the volume or size of a material as it is heated
• threatened species: a generic term for any species listed as having a high threat of extinction under the Biodiversity Conservation Act 2016 or the Fisheries Management Act 1994, due to a reduction in population size, restricted geographical distribution or there being few mature individuals in the population. Threatened species are listed in one of four categories in increasing order of severity: vulnerable; endangered; critically endangered; extinct
• tidal inundation: the flooding of land or coastal areas caused by the rise of tidal waters
• Tinderbox Drought: southeast Australia experienced three consecutive years of intense drought, from 2017 to 2019. This extreme climate threatened water supplies, damaged agricultural and ecological systems, and contributed to Australia’s Black Summer fire disaster, so it has been named the Tinderbox Drought to highlight the connection between drought and fire that typified this event
• translocated native species: a plant or animal that occurs naturally in some part of Australia but has been introduced to another region and become established where it does not naturally occur
• transmission (electricity supply): the bulk movement of electrical energy from a generation site (such as a power plant) to an electrical substation. The interconnected lines which facilitate this movement are known as a transmission network. The distribution network then moves this energy from the substation to the end user. Transmission and Distribution losses refer to the proportion of electrical energy lost between the generation site and the end user, the magnitude of which is influenced by the ambient temperature and length of transmission and distribution lines
• turbidity: a measure of the amount of suspended solids (usually fine clay or silt particles) in water and thus the degree of scattering or absorption of light in the water

U

• unregulated rivers: (water resources) rivers without major dams or regulating structures (see also regulated rivers)
• urban heat island effect: the phenomenon where urban areas experience higher temperatures than their surrounding rural areas due to human activity and the built environment
• upwelling: divergence of water currents or the movement of warm surface water away from land leading to a ‘welling up’ of deeper water that is commonly richer in nutrients, with the combination of nutrients and warmth leading to abundant algal growth

V

• Vascular plants: plants found on land that have specialised tubes (such as stems and roots) to transport water, minerals and food throughout the body of the plant
• vegetation class: a more detailed description of vegetation than formations, based on the dominant structure or growth-form, supplemented by selected details of plant composition, location or environmental characteristics that help to best identify it. In NSW, there are 99 vegetation classes as defined by Keith
• vegetation community: a group or assemblage of plant species that tend to grow together in similar environmental conditions, where the association of species helps to identify or describe the plant community
• vegetation condition: the health of native vegetation communities which reflects the level of naturalness and is commonly assessed against a benchmark taking account of factors such as structural integrity, species composition, presence or absence of weeds and diseases and reproduction of species
• vegetation formation: broad groups of plants distinguished by major structural and physiognomic features (relating to physical appearance or form). In NSW, there are 12 vegetation formations ()
• vegetation structure: the organisation of plants within a plant community or assemblage, consisting of one or more layers or strata and the dominant growth form for each strata
• vehicle kilometres travelled: a function of the number of motor vehicles on the road and the average distance travelled by each vehicle
• vertebrates: animals that have a backbone and spinal column – vertebrates include fishes, sharks and rays, amphibians, reptiles, mammals, and birds
• vulnerable species: a species (or population or ecological community) facing a high risk of extinction in NSW in the medium-term future, but not considered to be endangered

W

• Weed: a non-native plant or native plant removed from its natural habitat having, or with the potential to have, negative environmental, economic, or social impacts
• wilderness: an area which, together with its plant and animal communities is relatively natural and has not been significantly modified by humans and that is of sufficient size to make its maintenance in such a state feasible; it can provide opportunities for solitude and self-reliant recreation
• woody vegetation: for vegetation monitoring using Landsat MSS satellite sensors, vegetation formations (mainly woodlands and forests) that are over two metres high and with more than 20% canopy cover; also known as ‘detectable native forest’