Australian Water Information Dictionary

Alphabetical list of items

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

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D8-9S

GEODATA 9 Second Flow Direction Grid derived from DEM-9S. A grid describing the principal directions of surface drainage across the whole of Australia.

Source: Geoscience Australia

Related:

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dam

A barrier to obstruct the flow of water, especially one of earth, masonry, etc., built across a stream.

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data management system

The software and hardware used to manage the storage of and access to information held in a set of related files.

Source: Water Regulations 2008 Regulation 1.03

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data owner

An organisation responsible for managing the collection of environmental and water observations (data) and information about these measurements (metadata). The designated owner may differ from the data provider.

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data provider

An organisation that provides data and metadata to the Bureau. The designated data provider may differ from the data owner.

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data subcategory 3a (storages)

Level of water held in a major storage, expressed in metres relative to specified datum and the time of the observation.

Source: Water Regulations 2008 Schedule 3 Part 4

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data subcategory 3b (storages)

Volume of water held in a major storage, expressed in megalitres and the time of the observation.

Source: Water Regulations 2008 Schedule 3 Part 4

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date reported – collection of water storages

The date for which the published aggregated volume was calculated.

Related FAQ

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date reported – single water storage

The date on which the published measurement was observed.

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datum

A point, plane, or surface to which systems of measurement are referred or related to one another.

Source: Geoscience Australia, viewed 10th July 2013.

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day

A period of 24 hours starting at 12:00 midnight.

Source: Water Regulations 2008 Regulation 1.04

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dead storage

In a water storage, the volume of water stored below the level of the lowest outlet (the minimum supply level). This water cannot be accessed under normal operating conditions.

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dead storage capacity

The portion of total storage capacity that is equal to the volume of water below the level of the lowest outlet (the minimum supply level). This water cannot be accessed under normal operating conditions. See the water storage diagram for more information.

Related: minimum supply level

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dead storage water

Water in a storage that is below the elevation of the lowest constructed outlet.

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decile

One of a series of threshold values that divides a set of ordered data into 10 groups with an equal number of data points in each.

For example, consider a dataset of annual rainfall totals arranged in increasing order. The first decile is a value with 10% of the data below it and 90% above it. The eighth decile is a value with 80% of the data below it and 20% above it.

Related: quantile

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declared water service

Water service, or part of a water service, declared under chapter 2A, part 5A, division 2 of the Water Act 2000 (Queensland).

Source: Water Act 2000 (Qld) Schedule 4 – Dictionary

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deep drainage

The volume of water that moves below vegetation root zones which may or may not enter the saturated zone and become recharge to the groundwater system.

Source: © Commonwealth of Australia 2005, National Water Commission, Australian Water Resources 2005, Glossary and definitions, Viewed 5 October 2011, http://www.water.gov.au/Glossary.aspx

Related: zone of saturation

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DEM-9S

GEODATA 9 Second Digital Elevation Model. A grid of ground level elevation points covering the whole of Australia with a grid spacing of 9 seconds in longitude and latitude (approximately 250 metres) in the GDA94 coordinate system.

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deploy

To prepare an instrument to retrieve data, then take measurements in contact with the water in its data retrieval mode.

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depth

The vertical distance below the free water surface of a stream to a point of reference, e.g. a measuring instrument, or the bottom of the stream at any point on a cross-section.

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depth cell

A volume of water at a known distance and orientation from the transducer.

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dermosols

Moderately deep and well-drained soils of wetter areas in eastern Australia. Can be strongly acidic in the high rainfall areas or highly alkaline if they contain calcium carbonate.

Source: R F Isbell, 1996, The Australian Soil Classification, CSIRO Publishing, Melbourne.

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desalinated water

Volume of water sourced from desalination processes.

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desalination

The process of removing salt from brackish or saline water.

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DGPS

Differential Global Positioning System

An enhancement to Global Positioning System (GPS) that uses a network of fixed ground based reference stations to broadcast the difference between the positions indicated by the satellite systems and the known fixed positions.

The underlying premise of differential GPS is that any two receivers that are relatively close together will experience similar atmospheric errors. DGPS requires that a GPS receiver be set up on a precisely known location. This GPS receiver is the base or reference station. The base station receiver calculates its position based on satellite signals and compares this location to the known location. The difference is applied to the GPS data recorded by the second GPS receiver, which is known as the roving receiver. The corrected information can be applied to data from the roving receiver in real-time in the field using radio signals or through post-processing after data capture using special processing software.

Source: ESRI, viewed 17 April 2013. Copyright © 1995–2013 Esri.

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Differential Global Positioning System

An enhancement to Global Positioning System (GPS) that uses a network of fixed ground based reference stations to broadcast the difference between the positions indicated by the satellite systems and the known fixed positions.

The underlying premise of differential GPS (DGPS) is that any two receivers that are relatively close together will experience similar atmospheric errors. DGPS requires that a GPS receiver be set up on a precisely known location. This GPS receiver is the base or reference station. The base station receiver calculates its position based on satellite signals and compares this location to the known location. The difference is applied to the GPS data recorded by the second GPS receiver, which is known as the roving receiver. The corrected information can be applied to data from the roving receiver in real-time in the field using radio signals or through post-processing after data capture using special processing software.

Source: ESRI, viewed 17 April 2013. Copyright © 1995–2013 Esri.

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Digital Elevation Model (DEM)

A digital elevation model of the earth's surface.

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direct diversion

The volume of surface water abstracted when no prior allocation or other claim on the surface water existed.

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direct extraction

The volume of groundwater abstracted when no prior allocation or other claim on the groundwater existed.

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discharge

Volume of liquid flowing through a cross-section in a unit time.

Source: AS3778.1—2009 Clause 1.37. Reproduced with permission from SAI Global Ltd under Licence 1307-c151. This standard can be purchased online at http://www.saiglobal.com

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discharge from groundwater to surface water

Flow of groundwater from the saturated zone to streams, water storages, farm dams and natural surface water features. This is a form of groundwater-surface water interaction.

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distributed model

A hydrological model that takes into consideration the spatial variability of driving processes.

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diversion

Synonymous with abstraction in case the water is removed from the surface water store.

Synonym: abstraction

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domestic purposes

Domestic purposes are defined in the dictionary of the Water Act 2000 (Qld) (Schedule 4). While not stated explicitly, domestic purposes includes water used in connection with a residential dwelling including human consumption, cooking, toilets and showers etc. Watering of gardens up to 0.25 ha in size is also considered to be domestic use provided the produce from the garden is not grown for sale, barter or exchange.

Source: Water Act 2000 (Qld) Schedule 4 – Dictionary

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downward leakage to deep aquifers

The downward movement of groundwater from a shallow aquifer to a deeper, underlying aquifer.

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downward long-wave exposure

The total amount of terrestrial electromagnetic energy that falls on a specified unit horizontal surface.

Source: Water Regulations 2008 Schedule 3 Part 1

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downward long-wave irradiance

The long-wave irradiance emitted from the sky that falls on a specified unit horizontal surface.

Source: Water Regulations 2008 Schedule 3 Part 1

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DPS

Data Product Specification based on ISO 19139

Related: ISO

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drainage division

Representation of the catchments of major surface water drainage systems, generally comprising a number of river basins. In Australia, 12 drainage divisions were first defined in the 1960s by the Australian Water Resources Council. Australian drainage division boundaries were revised by the Bureau in 2010 in line with the creation of the Australian Hydrological Geospatial Fabric (Geofabric) based on the 9 second Digital Elevation Model.

Related: Bureau

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drought

A long period of abnormally low rainfall, especially one that adversely affects agriculture and other human activities. See the Climate page on drought for more information.

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dry-bulb air temperature

The temperature of air measured by a thermometer freely exposed to the air but shielded from radiation and moisture.

Source: Water Regulations 2008 Schedule 3 Part 1

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dryland agriculture

All agricultural crops and grassland cultivated for production with water input from rainfall only , i.e. no irrigated crops.

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dryland crops

All non-irrigated crops including cereals, oil seeds, sugar and legumes.

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dryland horticulture

All non-irrigated horticulture excluding intensive horticulture (e.g. glasshouses and shadehouses), which falls into the intensive use category. This category includes both perennial (e.g. tree fruits, tree nuts and vine fruits) and seasonal (e.g. fruits, nuts and herbs) horticulture.

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dryland pasture

All non-irrigated pastures including grazing modified pasture, exotic pasture, native pasture, woody fodder plants, pasture legumes and sown grasses.

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dryland salinity

Excessive salts in the soil surface and groundwater in non-irrigated areas. Although salts are a natural part of the Australian landscape, dryland salinity refers to excess salt that affects soil, native vegetation, biodiversity, crops and water quality.

Source: NSW Enviornment and Heritage - Dryland salinity

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