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Groundwater dependent ecosystem FAQs

This page provides information about Queensland GDE mapping conducted for areas of Queensland.

This includes the relationship between GDE mapping and wetland mapping in Queensland, how to access GDE mapping, detail on what information is contained in the mapping, how to use the mapping and much more.

GDE mapping FAQ PDF version

Related information

Bent wing bat Undara Lava Tubes Photo by Chris Sanderson

Quick facts

Dependence
means that the biodiversity values or ecological processes are influenced by the quality, quantity and/or timing of groundwater availability.

Search FAQ

What are groundwater dependent ecosystems (GDEs)?

See GDE ecology page

Why are groundwater dependent ecosystems (GDEs) important?

GDEs provide an array of ecological benefits including provision of:

  • habitat for flora and fauna, including rare and unique organisms
  • providing corridors for fauna
  • mitigating the effects of floods
  • reducing soil erosion
  • reducing sediment and nutrient loss
  • degrading pollutants and contaminants.

GDEs provide economic values including provision of:

  • water for human consumption
  • water for animal and plant production
  • tourism opportunities

GDEs provide social and cultural values including provision of:

  • recreational opportunities
  • local vistas for social activities
  • sites of cultural importance for indigenous people (e.g. springs)

Groundwater supports terrestrial and aquatic ecosystems by supporting vegetation and providing discharge to channels, lacustrine and palustrine wetlands, and both the estuarine and marine environment. Groundwater also plays a critical role during extended dry periods in maintaining refuges for flora and fauna.

How does urban and rural development affect groundwater dependent ecosystems (GDEs)?

Development can have impacts on GDEs including, but not limited to:

  • altering the hydrological regime in groundwater levels and environmental flows to GDEs
  • declining ecosystem health and mortality of some species caused by excessive draw down of groundwater levels which prevents access to groundwater by terrestrial GDEs[2]
  • increasing salinity through saltwater intrusion or rising groundwater levels can cause water stress, die back and mortality for GDEs[2]
  • reducing ecological integrity
  • facilitating the introduction of invasive fauna and flora
  • losing GDEs through land use change (e.g. land clearing for agriculture or mining activities)
  • introducing additional pollutants
  • accelerating soil erosion and sediment run-off.

What are the types of groundwater dependent ecosystems (GDEs)?

Queensland GDE mapping shows the geographic extent of three types of GDEs[1] based on the type of groundwater reliance. This typology is useful for management because it allows GDEs to be separated into easily recognisable types that permit the use of similar techniques and approaches for the identification of GDEs. The Queensland GDE mapping also contains attributes which provide further information about each GDE.

The three types of GDEs are:

  • ecosystems dependent on the surface expression of groundwater (surface expression GDEs or surface GDEs)
  • ecosystems dependent on the subsurface presence of groundwater (terrestrial GDEs)
  • ecosystems dependent on the subterranean presence of groundwater (subterranean GDEs).

What are the subtypes of groundwater dependent ecosystems (GDEs)?

Ecosystems dependent on the surface expression of groundwater

  • Lacustrine GDEs

    Lacustrine groundwater dependent ecosystems are lacustrine wetlands which require access to groundwater on a permanent or intermittent basis to meet all or some of their water requirements so as to maintain their communities of plants and animals, ecological processes and ecosystem services. Lacustrine wetland GDEs are lakes with gaining or variable gaining/losing groundwater connectivity which may be indicated by prolonged lake water availability regardless of surface water availability.

  • Palustrine GDEs

    Palustrine groundwater dependent ecosystems are palustrine wetlands which require access to groundwater on a permanent or intermittent basis to meet all or some of their water requirements so as to maintain their communities of plants and animals, ecological processes and ecosystem services. Palustrine GDEs are palustrine wetlands with either a gaining or variable gaining/losing groundwater connectivity.

  • Riverine GDEs

    Riverine groundwater dependent ecosystems are riverine wetlands which require access to groundwater on a permanent or intermittent basis to meet all or some of their water requirements so as to maintain their communities of plants and animals, ecological processes and ecosystem services. Riverine GDEs have either a gaining or variable gaining/losing groundwater connectivity.

  • Estuarine GDEs

    Estuarine groundwater dependent ecosystems are estuarine ecosystems which require access to groundwater on a permanent or intermittent basis to meet all or some of their water requirements so as to maintain their communities of plants and animals, ecological processes and ecosystem services. Estuarine GDEs have a gaining or variable gaining/losing groundwater connectivity.

  • Marine GDEs

    Marine groundwater dependent ecosystems are near-shore marine ecosystems which require access to groundwater on a permanent or intermittent basis to meet all or some of their water requirements so as to maintain their communities of plants and animals, ecological processes and ecosystem services. Marine GDEs are aquatic ecosystems dependent on the submarine discharge of groundwater. Marine GDEs have a gaining or variable gaining/losing groundwater connectivity.

Ecosystems dependent on the subsurface presence of groundwater

  • Riverine wetland GDEs

    Riverine wetland groundwater dependent ecosystems are riverine wetlands which require access to groundwater on a permanent or intermittent basis to meet all or some of their water requirements so as to maintain their communities of plants and animals, ecological processes and ecosystem services[4]. Riverine wetland GDEs are terrestrial riparian ecosystems dependent on the subsurface presence of groundwater accessed via their roots at depth.

  • Terrestrial GDEs

    Terrestrial groundwater dependent ecosystems are terrestrial ecosystems which require access to groundwater on a permanent or intermittent basis to meet all or some of their water requirements so as to maintain their communities of plants and animals, ecological processes and ecosystem services. Terrestrial GDEs are terrestrial ecosystems dependent on the subsurface presence of groundwater accessed via their roots at depth. This may be indicated by prolonged vegetation vigour during times of lower surface water availability.

Ecosystems dependent on the subterranean presence of groundwater

  • Aquifer GDEs

    Aquifers are inherently groundwater dependent. Aquifer ecosystems are composed of those species that inhabit the void between sediment grains or in fractures and solution cavities in groundwater systems.

  • Cave GDEs

    Cave groundwater dependent ecosystems are cave ecosystems which require access to groundwater on a permanent or intermittent basis to meet all or some of their water requirements so as to maintain their communities of plants and animals, ecological processes and ecosystem services[4]. Cave GDEs are caves dependent on the subterranean presence of groundwater. Cave GDEs may be indicated by high moisture levels and/or the presence of stygofauna.

What subtypes of groundwater dependent ecosystems are mapped in the Queensland GDE mapping?

Type Subtype of GDE Mapping layers
Ecosystems dependent on the surface expression of groundwater

Lacustrine GDE

Palustrine GDE

Riverine water body GDE

Points: represent lacustrine, palustrine wetland and riverine water body GDEs below the scale cut-off for polygon representation (spring ecosystems)
Lines: represent riverine water body GDEs (channels) that are potentially receiving groundwater discharge
Polygons (or areas): represent lacustrine and palustrine wetlands and riverine water body GDEs above the scale cut-off for point representation
Ecosystems dependent on the subsurface presence of groundwater

Terrestrial GDEs

Riverine wetland GDEs

Polygons (or areas): represent regional ecosystems that are potentially depending on the subsurface presence of groundwater within rooting depth
Ecosystems dependent on the subterranean presence of groundwater Cave GDEs Polygons (or areas): represent cave GDEs

What is a spring?

Springs are hydrogeological features by which groundwater discharges naturally to the land surface or cave. This includes springs with:

  • permanent and non-permanent (i.e. intermittent or ephemeral) saturation regimes
  • dynamic or static spatial locations
  • diffuse or point source spatial locations.

Click here for more information on springs

What is the difference between a spring and a groundwater dependent ecosystem (GDE)?

See what is a spring?

An ecosystem on the land surface may be dependent on this surface expression of groundwater (whether the expression is permanent or non-permanent, diffuse or point source, or dynamic or static in spatial location) and this ecosystem would be groundwater dependent ecosystem.

Click to enlarge

Are all groundwater dependent ecosystems (GDEs) associated with a spring?

Not all groundwater dependent ecosystems are associated with a spring.

Ecosystems dependent on the sub-surface presence of groundwater (e.g. a terrestrial ecosystem) will not be associated with a spring as the groundwater will not express at the surface.

An ecosystem dependent on the surface expression of groundwater will always be associated with a spring, for example, palustrine wetland (e.g. swamps), lacustrine wetland (e.g. lakes), riverine wetland (e.g. streams) and estuarine and near-shore marine.

How far does a spring extend on the surface?

The surface extent of the spring is limited to the spatial extent where groundwater discharges to the surface. Therefore a spring does not extend downslope despite the fact that the groundwater discharged by a spring might move downslope. For example, a spring at a fixed spatial location with a permanent saturation regime will be defined by the extent of the spring vent. However, a groundwater dependent wetland on the surface associated with the spring may extend much further than the spring extent.

Click to enlarge

How far does a groundwater dependent ecosystem (GDE) extend from a spring?

There is no standard distance a groundwater dependent ecosystem extends from a spring as they reflect local conditions. For example, a spring with diffuse discharge into a river can support surface expression riverine groundwater dependent ecosystems for several hundred meters to kilometres depending on the spring flow rate, spring extent, and local hydrogeological characteristics. In arid environments, a spring with a permanent saturation regime and a fixed spatial location may only support a surface expression palustrine groundwater dependent ecosystem extending less than one hectare from the spring vent.

Click to enlarge

Why was the Queensland groundwater dependent ecosystem (GDE) mapping produced?

Agreements were made, under the 1994 Council of Australian Governments Water Reform Framework and the 2004 Intergovernmental Agreement on a National Water Initiative to include provisions of water for the environment in groundwater management and planning. Understanding and managing GDEs and their associated function and value is central to attaining these outcomes.

The Queensland Government has recognised the need to consistently map ecosystem dependence on groundwater and to make this information accessible to decision makers in a manner which is consistent with existing data sets.

The Queensland GDE mapping project contributed to the development and review of a National GDE Atlas through knowledge sharing and evaluation of both methods and products. This method relies on the use of an iterative consultative process to ensure the mapping is developed with the optimal use of both expert knowledge and existing spatial information.

How is the Queensland groundwater dependent ecosystem (GDE) mapping produced?

Queensland GDE mapping is produced using a consultative process that collates expert knowledge about GDEs in a landscape and develops mapping rules to identify those ecosystems through the ‘Walking the landscape’ process. These mapping rules are then applied to the best available spatial data in the Geographic Information System (GIS) to delineate areas that are likely to be groundwater dependent. Information about relevant landscape processes is captured in pictorial conceptual models. These conceptual models collate valuable supporting information to improve our understanding of the landscape processes that produce GDEs, the broader issues of context and function of GDEs, and to assist in the estimation of GDE extent delineated in the GDE mapping.

The Queensland Government has integrated regional ecosystem and wetland mapping data into the GDE mapping process. The Queensland GDE mapping is produced with the aim to ensure that the mapping products fit with existing mapping programs and could be maintained and updated into the future.

Where can I find the Queensland Groundwater Dependent Ecosystem (GDE) Mapping Method?

The GDE mapping background and method can be found here.

Where can I find the attribution for the Queensland groundwater dependent ecosystem (GDE) mapping?

The GDE attributions can be found on the groundwater dependent ecosystem spatial datasets and attribute fields page.

How can I use the KMLs?

To find out how to use KMLs go to the get mapping help page.

What are the major source data sets for the groundwater dependent ecosystem (GDE) mapping?

The GDE mapping combines several major source datasets to create GDE mapping:

  • Biodiversity status of pre-clearing and remnant regional ecosystems
  • Queensland wetland data
  • Queensland karst mapping.

What are the Queensland groundwater dependent ecosystem (GDE) pictorial conceptual models?

Pictorial conceptual models are representations of observed objects, phenomena and processes in a logical and objective way with the aim of constructing a formal system whose theoretical consequences are not contrary to what is observed in the real world. Pictorial conceptual models evoke the real world by presenting enough visual cues to give the reader a clear context for the relationships, processes or elements the model seeks to explain[3]. Queensland GDE pictorial conceptual models capture the collective knowledge available of the key conditions controlling groundwater and ecosystem interaction in a specific landscape.

Why are the Queensland groundwater dependent ecosystem (GDE) pictorial conceptual models produced?

Queensland GDE pictorial conceptual models are produced to collate cross-disciplinary knowledge regarding the components, processes and interrelationships in a system that are critical to the presence, function and form of GDEs. GDE pictorial conceptual models are a tool that supports the communication of technical scientific concepts to end users to increase understanding and assist environmental managers in decision making.

Was field verification of Queensland groundwater dependent ecosystem (GDE) mapping carried out?

Where possible, existing research has been used to corroborate the expert knowledge used in the mapping process (see What the confidence rating means?). Field verification, including either qualitative or detailed quantitative measurements of GDEs at specific locations, has not been undertaken as part of the current GDE mapping process. Although such an assessment would significantly improve the accuracy of the mapping, this type of work would require significant funding and resourcing and is often not practical to complete over large areas. Field assessment techniques are outlined in the Australian groundwater-dependent ecosystems toolbox.

Will the Queensland groundwater dependent ecosystem (GDE) mapping information be updated?

The intent is that the GDE mapping will be updated in line with resources and needs. This will take the form of:

  • improving the accuracy of the existing mapping
  • extending mapping to other spatial areas
  • mapping additional GDE types and subtypes
  • improving the source datasets used in GDE mapping (e.g. wetland and regional ecosystem mapping).

The GDE mapping combines information from multiple source datasets (including wetland and regional ecosystem information). The source datasets provide the point, line and area features in the GDE mapping. Further information on how GDE mapping links to other mapping products in Queensland can be found here.

What is the relationship between the National Groundwater Dependent Ecosystems Atlas (National GDE Atlas) and the Queensland GDE mapping?

The National GDE Atlas combines nationwide layers of satellite remote sensing data with existing literature and mapping. Queensland’s GDE mapping builds on existing information, including wetland mapping, regional ecosystem mapping, a spring and small waterholes database, and drainage lines. This information is combined with feedback from a broad range of experts. The definitions and mapping attributes used in the National GDE Atlas and the Queensland GDE mapping were developed collaboratively. Mapping data sets from the Queensland GDE mapping are available for integration into the National GDE Atlas when it is next updated.

How should the Queensland groundwater dependent ecosystem (GDE) mapping be used?

The Queensland GDE mapping products are tools to support natural resource management decision making. The mapping indicates the likely locations of GDE at a regional scale and provides descriptions and system understanding where possible of the ecosystems. The GDE mapping should be used with other information to assist environmental managers in making resource management decisions aimed at the sustainable management of key environmental assets which may be dependent on groundwater. The Queensland GDE mapping is most suitable for use at the regional scale and can indicate where finer scale assessments may be necessary. While the mapping products may provide an input to policy and legislative processes they should not be used as statutory maps. Map users are advised to check the GDE mapping confidence rating.

The Queensland GDE mapping does not presently indicate the detailed level of ecosystem dependence on groundwater, the values of the ecosystem, and the condition of the ecosystem or their environmental water requirements. Rather these maps should be used to inform more detailed local-scale assessment of GDEs including field assessments.

What does the Queensland groundwater dependent ecosystem (GDE) confidence rating mean?

Each ecosystem identified as potentially groundwater dependent has been assigned a confidence rating to indicate the level of confidence experts had in their prediction that the ecosystem is using groundwater as opposed to other water sources (e.g. soil water or surface water). Confidence is rated according to the level of confidence experts had in the developed mapping rule set that identified the specific ecosystem as groundwater dependent. The confidence ratings of GDE mapping are:

  • Known GDE

    According to expert knowledge and supporting evidence (e.g. field validation), the mapped ecosystem has been accurately identified as having some degree of groundwater dependence.

  • Derived GDE–High confidence

    According to expert knowledge, there is a high confidence in the mapping rule set and therefore in the prediction that the mapped ecosystem has some degree of groundwater dependence.

  • Derived GDE–Moderate confidence

    According to expert knowledge, there is a moderate confidence in the mapping rule set and therefore in the prediction that the mapped ecosystem has some degree of groundwater dependence.

  • Derived GDE–Low confidence

    According to expert knowledge, there is a low confidence in the mapping rule set and therefore in the prediction that the mapped ecosystem has some degree of groundwater dependence.

  • Unknown confidence

  • According to expert knowledge, the confidence in the mapping rule set is yet to be determined and therefore the confidence in the prediction that the mapped ecosystem has some degree of groundwater dependence is yet to be determined.

Does the Queensland groundwater dependent ecosystem (GDE) mapping contain information on the level of groundwater use by an ecosystem?

The Queensland GDE mapping contains a number of attributes describing the level of groundwater use by an ecosystem, although these may not be populated for all GDEs. Flora and fauna within an ecosystem may also have different levels of groundwater use that can vary spatially and temporally. Factors that may affect groundwater use include flora physiology, availability of other water sources, existing hydrological regime and groundwater quality.

Does the Queensland groundwater dependent ecosystem (GDE) mapping contain information on ecosystem condition?

The Queensland GDE mapping contains limited information about ecosystem condition. The GDE mapping contains a few attributes describing hydrological and salinity modification which is derived from the source wetland mapping dataset. Other GDE condition information is not included in the GDE mapping. As the GDE mapping is linked to wetlands and regional ecosystem mapping, the attributes in these latter data sets may contain some additional information which might help in some condition assessment processes.

How can I view the Queensland groundwater dependent ecosystem (GDE) mapping products?

To view the mapping products go to the following pages:

How can I get or view the Queensland groundwater dependent ecosystem (GDE) mapping?

To view the GDE mapping go to the get mapping help page.

Where can I find the Queensland groundwater dependent ecosystem (GDE) pictorial conceptual models?

To view the GDE conceptual models go to the conceptual models page.

Where can I find the metadata for Queensland groundwater dependent ecosystem (GDE) mapping?

To find and view the GDE metadata go to the metadata page.

Is the whole polygon delineated as a Queensland groundwater dependent ecosystem (GDE) in all cases?

Each GDE extent shows an area where groundwater and ecosystems interaction may be occurring; however, not all ecosystems within that area may necessarily be groundwater dependent. For example, a regional ecosystem GDE polygon may be identified as potentially groundwater dependent but in fact only a portion of the vegetation within the identified polygon depends on groundwater to maintain communities, processes and services and is therefore groundwater dependent. An estimate of the proportion of an area that is groundwater dependent is provided in the attribute field ‘GDE_PCT’. The values are as follows:

  • Specific percentage

    The estimated percentage of the area that is potentially groundwater dependent.

  • Contains GDE

    The proportion of the area that is potentially groundwater dependent is not estimated.

  • 01-50_GDE

    1% to 50% of the area is potentially groundwater dependent.

  • 51-80_GDE

    51% to 80% of the area is potentially groundwater dependent

  • 81-100_GDE

    81% to 100% of the area is potentially groundwater dependent.

Are all groundwater dependent ecosystems (GDEs) shown in the Queensland GDE mapping?

Not all GDEs are identified and captured in the Queensland GDE mapping due to a large reliance on existing data sets and landscape-scale analysis supported by expert knowledge. GDEs may not be identified and captured where ecosystems are:

  • very small and not captured in source datasets
  • very small and so are not captured in the landscape-scale analysis
  • particular subtypes of GDEs (e.g. estuarine and marine)
  • located in areas outside the present survey coverage.

Why are there overlapping groundwater dependent ecosystems (GDEs)?

Overlapping GDEs could indicate:

  • the presence of multiple types of GDEs

    For example, overlapping polygons may indicate that one geographic location may contain both ecosystems dependent on the subsurface presence of groundwater which they access through the capillary zone and ecosystems dependent on the surface expression of groundwater (e.g. channel or wetland).

  • one type of GDE which may be identified through multiple mapping rule sets

    One ecosystem may be identified and captured as groundwater dependent by two different mapping rule sets capturing different combination of factors that lead to groundwater dependence. For example, one ecosystem may be captured because of its position on alluvia and may also be captured again because of its position near or connection to other permeable rocks.

What do blank and white spaces in the Queensland groundwater dependent ecosystem (GDE) mapping mean?

Blank or white space on the map could indicate that the area:

  • contains ecosystems that have been assessed as not groundwater dependent
  • is outside the present mapping coverage for GDEs
  • contains no mapped ecosystems (for example, cleared areas).

Why may borders be visible in the Queensland groundwater dependent ecosystem (GDE) mapping?

Visible borders on the map could indicate:

  • boundaries between different data sets used to develop the GDE mapping. This may result from different mapping scale, accuracy, currency or availability between data sets
  • application of different mapping rule sets to different regions based on expert knowledge.

What geographic area does the Queensland groundwater dependent ecosystem (GDE) mapping cover?

Get mapping version history

What scale is the Queensland groundwater dependent ecosystem (GDE) mapping?

To find and view the GDE metadata go to the metadata page.

How accurate is the Queensland groundwater dependent ecosystem (GDE) mapping?

To find and view the GDE metadata go to the metadata page.

What is the currency of the Queensland groundwater dependent ecosystem (GDE) mapping?

To view the GDE go to the mapping version history on the GDE mapping background page.

Where can I find technical specifications for the Queensland groundwater dependent ecosystem (GDE)mapping?

The technical specifications for the Queensland GDE mapping data are available on request. The following technical specifications are available:

  • Queensland Groundwater Dependent Ecosystem Technical Mapping Specifications: General Application of the Queensland Groundwater Dependent Ecosystem Mapping and Classification Method
  • Queensland Groundwater Dependent Ecosystem Technical Mapping Specifications: Module One—Eastern Murray–Darling Basin (superseded by module eight)
  • Queensland Groundwater Dependent Ecosystem Technical Mapping Specifications: Module Two—Wide Bay–Burnett
  • Queensland Groundwater Dependent Ecosystem Technical Mapping Specifications: Module Three—Pumicestone Passage
  • Queensland Groundwater Dependent Ecosystem Technical Mapping Specifications: Module Four—Mackay–Whitsundays
  • Queensland Groundwater Dependent Ecosystem Technical Mapping Specifications: Module Five—South East Queensland
  • Queensland Groundwater Dependent Ecosystem Technical Mapping Specifications: Module Six—Lake Eyre Basin and surrounding drainage sub-basins
  • Queensland Groundwater Dependent Ecosystem Mapping Technical Specifications: Module Seven—Comet, Dawson and Mackenzie River drainage basin sub-areas
  • Queensland Groundwater Dependent Ecosystem Mapping Technical Specifications: Module Eight—Eastern Murray-Darling Basin

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References

  1. ^ Eamus, D, Froend, R, Loomes, R, Hose, G & Murray, B 2006, 'A functional methodology for determining the groundwater regime needed to maintain the health of groundwater-dependent vegetation', Australian Journal of Botany, vol. 54, no. 2, pp. 97-114.
  2. ^ a b Nielsen, D, Brock, M, Rees, G & Baldwin, D 2003, 'Effects of increasing salinity on freshwater ecosystems in Australia', Australian Journal of Botany, vol. 51, p. 655.
  3. ^ Pictures worth a thousand words: A guide to pictorial conceptual modelling 2012, Department of Environment and Heritage Protection, Queensland Wetlands Program, Queensland Government, Brisbane, <http://wetlandinfo.derm.qld.gov.au/wetlands/resources/pictorial-conceptual-models.html>.
  4. ^ a b Richardson, E, Irvine, E, Froend, R, Book, P, Barber, S & Bonneville, B 2011, Australian groundwater dependent ecosystems toolbox part 1: assessment framework, National Water Commission, Canberra.

Last updated: 12 May 2015

This page should be cited as:

Groundwater dependent ecosystem FAQs, WetlandInfo 2012, Queensland Government, Queensland, viewed 13 April 2017, <https://wetlandinfo.ehp.qld.gov.au/wetlands/facts-maps/gde-background/gde-faq/>.

Queensland Government
WetlandInfo   —   Department of Environment and Heritage Protection