A geocentric (earth-centred) coordinate reference system that is Australia’s official national datum (since December 2017). It is a plate-fixed datum that is aligned with the 2014 realisation of the International Terrestrial Reference Frame 2014.

GDA2020 coordinates differ from GDA94 coordinates by approximately 1.5 to 1.8 metres.

For more information on GDA94 and GDA2020 see Intergovernmental Committee on Surveying and Mapping

Source: Intergovernmental Committee on Surveying and Mapping, viewed 05 December 2018.

This definition applies to:

Glossary for Standards: National Industry Guidelines for hydrometric monitoring

GDA94

Geocentric Datum of Australia 1994

A coordinate reference system whose origin coincides with a determination of the centre of mass of the earth, hence the term ‘geocentric’. GDA94 is a plate-fixed or static coordinate datum based on the International Terrestrial Reference Frame 1992, held at the reference epoch of 1 January 1994.

GDA94 was the official geodetic datum before GDA2020.

For more information on GDA94 and GDA2020 see Intergovernmental Committee on Surveying and Mapping

Source: Intergovernmental Committee on Surveying and Mapping, viewed 2 October 2018.

This definition applies to:

Glossary for Standards: National Industry Guidelines for hydrometric monitoring

GDE

groundwater dependent ecosystem

This definition applies to:

Glossary for Water data: National Atlas of Groundwater Dependent Ecosystems

GDE potential

Describes ecosystems in terms of their 'potential to be interacting with groundwater'. The classes mapped in the GDE Atlas are:

High potential for groundwater interaction
Moderate potential for groundwater interaction
Low potential for groundwater interaction

The term 'potential' is used to reflect the uncertainty inherent in identifying ecosystems as groundwater-dependant using desktop methods. Finer scale studies or fieldwork are needed to confirm this analysis.

This definition applies to:

Glossary for Water data: National Atlas of Groundwater Dependent Ecosystems

general purpose water accounting report

A water accounting report intended to meet the information needs common to users who are unable to command the preparation of water accounting reports tailored to satisfy their information needs. A general purpose water accounting report is prepared in accordance with Australian Water Accounting Standards and comprises a Contextual Statement, an Accountability Statement, water accounting statements and accompanying note disclosures.

This definition applies to:

generalised short-duration method

Appropriate for estimating probable maximum precipitation for durations up to six hours and for an area of less than 1000 square kilometres.

Related: probable maximum precipitation

This definition applies to:

Glossary for Water status: Design rainfalls

generalised southeast Australia method

Appropriate for estimating probable maximum precipitation in regions of Australia where tropical storms are not the source of the greatest rainfall depths and where topographic influences vary markedly.

Related: probable maximum precipitation

This definition applies to:

Glossary for Water status: Design rainfalls

generalised tropical storm method – revised (GTSMR)

Appropriate for estimating probable maximum precipitation in regions of Australia affected by tropical storms.

Related: probable maximum precipitation

This definition applies to:

Glossary for Water status: Design rainfalls

GEODATA

A national set of topographic products developed by Geoscience Australia at various scales.

This definition applies to:

Glossary for Water data: Geofabric

Geofabric

The common abbreviation for the Australian Hydrological Geospatial Fabric.

This definition applies to:

Geofabric Groundwater Cartography

A first pass national groundwater GIS dataset. Groundwater boundaries are derived from interim groundwater data.

This definition applies to:

Glossary for Water data: Geofabric

Geofabric Hydrology Reporting Catchments

A contracted catchments hierarchy resulting from contracted nodes of important hydrological features. A simplified Node-Link network identifies contracted nodes in Geofabric Surface Network and the corresponding linkages between these nodes.

This definition applies to:

Glossary for Water data: Geofabric

Geofabric Hydrology Reporting Regions

A collection of GIS feature classes derived from aggregations of contracted catchments in the Geofabric Hydrology Reporting Catchments product. Data is aggregated to drainage divisions and river region reporting units.

This definition applies to:

Glossary for Water data: Geofabric

Geofabric Surface Cartography

A collection of GIS feature classes of surface water features of Australia (excluding external Territories). It is flow directed and provides input for the production of maps and visualisations that present the results of hydrological analyses.

Source: Geofabric Product Guide V2.0

This definition applies to:

Glossary for Water data: Geofabric

Geofabric Surface Catchments

A collection of GIS feature classes providing topographic based surface catchment boundaries, organised into a hierarchy using the Pfafstetter reference system. It has a hydrological relationship to surface water features and can be used for surface hydrological analysis.

Source: Geofabric Product Guide V2.0

This definition applies to:

Glossary for Water data: Geofabric

Geofabric Surface Network

A collection of GIS feature classes based upon the DEM derived ANUDEM Streams. It is a generalised representation of Geofabric Surface Cartography streams with the addition of full topological connection. It can be used for selecting hydrological observation points (if they exist) and for geoprocessing and hydrological modelling that involves streamflow tracing operations.

Source: Geofabric Product Guide V2.0

This definition applies to:

Glossary for Water data: Geofabric

Geofabric Version 1

The first major release of Geofabric data in 2010 derived from foundation input data at scale 1:250 000. Three products were included: Geofabric Surface Cartography, Geofabric Surface Catchments, Geofabric Surface Network.

This definition applies to:

Glossary for Water data: Geofabric

Geofabric Version 2

The second major release of Geofabric data in 2011 derived from foundation input data at scale 1:250 000. Six products were included: Geofabric Surface Cartography, Geofabric Surface Catchments, Geofabric Surface Network, Geofabric Hydrology Reporting Catchments, Geofabric Hydrology Rerpoting Regions, Geofabric Groundwater Cartography.

This definition applies to:

Glossary for Water data: Geofabric

Geographic Information System

A system used for the design, capture, storage, management and analysis of geographic data. Often referred to as GIS.

Related: Geographic Information System

This definition applies to:

geologic unit

One of the tiers in the National Aquifer Framework. Smallest mapped or defined geological entity consistent at a national scale.

This definition applies to:

Glossary for Standards: National Aquifer Framework

georaster

A catalog of raster datasets describing properties of hydrogeologic units (e.g. depth or elevation of hydrogeologic unit's top or base, salinity and groundwater level).

This definition applies to:

Glossary for Water data: National Groundwater Information System

Geoscience Australia

Australia's national geoscience agency.

GA
GEODATA

This definition applies to:

Glossary for Water data: Geofabric

geovolume

A three dimensional multipatch feature class that represents hydrogeologic units as a volume.

This definition applies to:

Glossary for Water data: National Groundwater Information System

GFS

groundwater flow system

This definition applies to:

Glossary for Water data: National Atlas of Groundwater Dependent Ecosystems

GGA

Data string that provides geographic position information determined by the GPS.

This definition applies to:

Glossary for Standards: National Industry Guidelines for hydrometric monitoring

gigalitre

1,000 megalitres, which also is 1,000,000,000 litres.

Related: gigalitre

This definition applies to:

GIS

Geographic Information System

A system used for the design, capture, storage, management and analysis of geographic data. Often referred to as GIS.

This definition applies to:

GL

gigalitre

1,000 megalitres, which also is 1,000,000,000 litres.

Related: gigalitre

This definition applies to:

global positioning system

A system of radio-emitting and -receiving satellites used for determining positions on the earth. The orbiting satellites transmit signals that allow a Global Positioning System receiver anywhere on earth to calculate its own location through trilateration. Developed and operated by the U.S. Department of Defense, the system is used in navigation, mapping, surveying, and other applications in which precise positioning is necessary.

This definition applies to:

Glossary for Standards: National Industry Guidelines for hydrometric monitoring

global solar exposure

The total amount of electromagnetic energy emitted from the sun that falls on a specified unit horizontal surface.

Source: Water Regulations 2008 Schedule 3 Part 1. For the latest information on Australian Government law please go to Federal Register of Legislation

This definition applies to:

global solar irradiance

The irradiance emitted from the sun that falls on a specified unit horizontal surface.

Source: Water Regulations 2008 Schedule 3 Part 1. For the latest information on Australian Government law please go to Federal Register of Legislation

This definition applies to:

GMU

groundwater management unit

An area delineated for the management of groundwater based on similar resource characteristics (for example rock type and watertable depth) and management rules that may be applied.

This definition applies to:

Glossary for Water status: Australian Water Resources Assessment

GPS

Global Positioning System

This definition applies to:

Glossary for Standards: National Industry Guidelines for hydrometric monitoring

GR4J

Modèle du Génie Rural à 4 Paramètres Journalier

A daily lumped four-parameter rainfall-runoff model, belonging to the family of soil moisture accounting models.

Source: Modèles Hydrologiques du Génie Rural

This definition applies to:

Glossary for Water forecasts: Dynamic streamflow

grace period

The period beginning on the day the person is specified in the new category and ending 3 months after that day.

Related FAQ: What is the grace period?

Source: Water Regulations 2008 Subregulation 7.04(1A). For the latest information on Australian Government law please go to Federal Register of Legislation

This definition applies to:

Glossary for Regulations: Water Regulations

gross water price

The transfer price of water as agreed between legal entities inclusive of all applicable transaction costs.

This definition applies to:

Glossary for Water status: Water Market Reports

groundwater

There are multiple contexts for this item

Context 1

Subsurface water in soils and geological formations that are fully saturated.

This definition applies to:

Context 2

(a) water occurring naturally below ground level (whether in an aquifer or otherwise) or (b) water occurring at a place below ground that has been pumped, diverted or released to that place for the purpose of being stored there. It does not include water held in underground tanks, pipes or other works.

In GDE Atlas, this definition includes the capillary fringe, which is an important source of water for many GDEs.

Source: Water Act 2007 Part 1 Section 4, at 8 Febraury 2019. For the latest information on Australian Government law please go to Federal Register of Legislation

Equivalent: water market equivalent terms

This definition applies to:

groundwater access entitlement

Water access entitlement granted on the groundwater resource.

This definition applies to:

groundwater allocation

Volume of water resulting from an allocation announcement made on a groundwater access entitlement.

This definition applies to:

groundwater allocation trade

A transaction to transfer a groundwater allocation from one legal entity to another, with or without change in location of the abstraction point.

This definition applies to:

groundwater assets

The water assets that relate to groundwater, excluding soil moisture and water held in works underground.

In the National Water Account, it is quantified as the total of managed groundwater volumes of each groundwater management unit significant to the water balance within the region. For example where available this managed volume corresponds to the permissible consumptive volume specified in the water management plan.

This definition applies to:

groundwater decreases

Outflows from the region's groundwater due to natural processes or diversions, and decrease of claims to water held on behalf of the region's groundwater.

This definition applies to:

Groundwater Dependent Ecosystem

Natural ecosystems that require access to groundwater to meet all or some of their water requirements on a permanent or intermittent basis, so as to maintain their communities of plants and animals, ecosystem processes and ecosystem services.

Source: Richardson, S., et al., (2011). Australian groundwater-dependent ecosystem toolbox part 1: assessment framework, Waterlines report, National Water Commission, Canberra

This definition applies to:

Glossary for Water data: National Atlas of Groundwater Dependent Ecosystems

groundwater entitlement lease

A transaction to transfer for a specified term a groundwater access entitlement from one legal entity to another, with or without change in location of the abstraction point.

This definition applies to:

groundwater entitlement trade

A transaction to transfer perpetually a groundwater access entitlement from one legal entity to another, with or without change in location of the abstraction point.

This definition applies to:

groundwater flow

Water that flows in aquifers and aquitards.

This definition applies to:

Glossary for Water status: Australian Water Resources Assessment

groundwater flow system

The system which represents the movement of subsurface water from the point where it enters the ground to where it leaves.

Source: Richardson, S., et al., (2011). Australian groundwater-dependent ecosystem toolbox part 1: assessment framework, Waterlines report, National Water Commission, Canberra

Related: groundwater flow

This definition applies to:

Glossary for Water data: National Atlas of Groundwater Dependent Ecosystems

groundwater increases

Inflows into the region's groundwater or increase of claims to water that may result in inflows into the region's groundwater.

This definition applies to:

groundwater inflows

Volume of physical inflows to groundwater during the reporting period; from outside the region or from other stores.

This definition applies to:

groundwater level

The level of groundwater in an aquifer, typically measured in a groundwater bore. In the case of an unconfined aquifer, the groundwater level is equal to the watertable level.

This definition applies to:

groundwater liability

A water liability relating to groundwater.

This definition applies to:

groundwater liability decreases

Decreases in the region's groundwater liability. It includes adjustment or forfeiture of the obligation to deliver groundwater. It excludes extraction of water.

This definition applies to:

groundwater liability increases

An increase in groundwater liability as a result of allocation announcements, etc.

This definition applies to:

groundwater management plan

A document providing information about groundwater access for users. It may include rules about transferring licence entitlements, and contain arrangements that allow carryover of groundwater entitlements. It may also outline water sharing arrangements during times of water shortage.

Source: Modified from Goulburn-Murray Water, viewed 25 July 2015.

This definition applies to:

Glossary for Water status: Water in Australia

groundwater management unit

An area delineated for the management of groundwater based on similar resource characteristics (for example rock type and watertable depth) and management rules that may be applied.

Synonym: GMU

This definition applies to:

Glossary for Water status: Australian Water Resources Assessment

groundwater outflows

Volume of physical outflows from groundwater during the reporting period; to outside the region or to other stores.

This definition applies to:

groundwater recharge

The infiltration or ingress of water to the saturated part of a geological layer. Infiltration of precipitation and its movement to the watertable is a form of natural recharge. Other forms of recharge are flooding and irrigation. Artificial recharge can also occur through various means, including bore injection.

This definition applies to:

groundwater resource potential

The maximum volume of groundwater that can be extracted without causing any long-term mining of the aquifer system. It does not represent a ‘sustainable’ or ‘safe’ yield that normally takes into account factors such as intrusion of poor quality water and surface water groundwater interaction. In an unconfined aquifer the groundwater resource potential is mainly based on estimation of groundwater recharge, while in a confined aquifer the groundwater resource potential represents the available elastic storage (or a fraction of throughflow).

This definition applies to:

groundwater rights

Water rights granted by a jurisdiction to access the region's groundwater.

This definition applies to:

groundwater store assets

Water assets that relate to groundwater but excluding soil moisture and water held in works underground.

Related: water asset

This definition applies to:

Glossary for Water status: National Water Account 2010

groundwater system

A collective term for areas that are defined normally at a higher level than groundwater management area, for the purposes of water data reporting.

Related: water system

This definition applies to:

Glossary for Water status: Water Market Reports

group water accounting report

The water accounting report of a group water report entity presented as a single water entity.

This definition applies to:

group water report entity

A water report entity comprising individual water entities and for which a group water accounting report is required to be prepared under a regulation, statute or directive.

This definition applies to:

GSAM