Authors / CoAuthors
Kilgour, P. | Symington, N.
Abstract
<div>Groundwater dependent ecosystems (GDEs) rely on access to groundwater on a permanent or intermittent basis to meet some or all of their water requirements (Richardson et al., 2011). The <a href="https://explorer-aws.dea.ga.gov.au/products/ga_ls_tc_pc_cyear_3">Tasseled Cap percentile products</a> created by Digital Earth Australia (2023) were used to identify potential GDEs for the South Nicholson-Georgina basins study area. These percentile products provide statistical summaries (10th, 50th, 90th percentiles) of landscape brightness, greenness and wetness in imagery acquired between 1987 and present day. The 10th percentile greenness and wetness represent the lowest 10% of values for the time period evaluated, e.g. 10th percentile greenness represents the least green period. In arid regions, areas that are depicted as persistently green and/or wet at the 10th percentile have the greatest potential to be GDEs. For this reason, and due to accessibility of the data, the 10th percentile Tasseled Cap greenness (TCG) and Tasseled Cap wetness (TCW) products were used as the basis for the assessment of GDEs for the South Nicholson-Georgina region. The 50th percentile greenness was utilised to create the coefficient of variance (CV) dataset. This data release is an ESRI geodatabase, with layer files, including: - combined classified 10th percentile greenness and wetness dataset (useful to identify potential groundwater dependent vegetation/other GDEs and differentiate between vegetation types) - CV of 50th percentile greenness dataset (useful when used in conjunction with the combined product to help identify groundwater dependent vegetation) For more information and detail on these products, refer to associated <a href="https://dx.doi.org/10.26186/149377">report</a>. </div><div><br></div><div><strong>References</strong></div><div>Digital Earth Australia (2023). <em><a href="https://docs.dea.ga.gov.au/">Digital Earth Australia User Guide.</a></em></div><div>Richardson, S., E. Irvine, R. Froend, P. Boon, S. Barber, and B. Bonneville. 2011a. <em>Australian groundwater-dependent ecosystem toolbox part 1: Assessment framework.</em> Waterlines Report 69. Canberra, Australia: Waterlines.</div><div><br></div>
Product Type
dataset
eCat Id
149293
Contact for the resource
Resource provider
Point of contact
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Point of contact
Digital Object Identifier
Keywords
- ( Project )
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- EFTF – Exploring for the Future
- ( Project )
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- South Nicholson Basin
- ( Project )
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- Georgina Basin
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- Remote sensing
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- Landsat
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- Groundwater Dependent Ecosystem
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- GDE
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- NT
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- Northern Territory
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- groundwater dependent vegetation
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- QLD
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- Tasseled Cap
- theme.ANZRC Fields of Research.rdf
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- Groundwater hydrology
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- Published_External
Publication Date
2024-08-07T21:35:43
Creation Date
2024-02-05T03:00:00
Security Constraints
Legal Constraints
Status
completed
Purpose
To assist in the identification and characterisation of groundwater dependent ecosystems.
Maintenance Information
notPlanned
Topic Category
geoscientificInformation
Series Information
Lineage
<div>For the South Nicholson – Georgina Basin, both TCG and TCW were extracted from Digital Earth Australia (DEA) using the Geoscience Australia Landsat Tasselled Cap Percentile Calendar Year Collection 3 product for all available years (1987– Aug 2023). Since there is currently no multi-year summary product based on the Collection 3 data, as per the Collection 2 data, a <a href="https://github.com/GeoscienceAustralia/GWB-GDE-DEA/tree/main/ExtractTCG_TCB_c3">script </a> was written in DEA Sandbox (<a href="https://app.sandbox.dea.ga.gov.au/">https://app.sandbox.dea.ga.gov.au/</a>) to extract all years and calculate the median of the percentiles (10th, 50th, 90th) for the whole time period.<strong> </strong>For this study, a combination of the 10th percentiles of TCG and TCW were investigated, as they are more informative for identifying and characterising potential aquatic and terrestrial GDEs than each band individually. The 50th percentile greenness was also used to create the coefficient of variance (CV) dataset. </div><div><br></div><div>The datasets created include:</div><div><br></div><div>- coefficient of variation of 50th percentile greenness dataset, created by modifying the above script and replacing ‘median’ with ‘std’ and ‘mean’ respectively, to acquire the standard deviation and mean for each pixel in the 50th percentile greenness datasets for the time period 1987 to 2022. These datasets were then loaded into a GIS and the CV dataset created by using the formula: CV = std/mean</div><div><br></div><div>- combined scaled 10th percentile greenness and wetness dataset, created by scaling both the greenness and wetness 10th percentile datasets using the scaling formula z = (x – min) / (max – min), which were then added together.</div><div><br></div><div>- classified 10th percentile greenness and wetness datasets (used as input for the combined classified dataset). These were created based on their normally distributed data using the mean and 0.5 standard deviations and classified into nine classes. </div><div><br></div><div>- combined classified 10th percentile greenness and wetness dataset was created by combining the classified greenness and wetness datasets using the ESRI ArcPro ‘Combine’ tool. This resulted in a dataset having a two-digit code with the first number of the code corresponding to greenness and the second digit correspond to wetness (refer to Table 2.1, Kilgour et al., 2023).</div><div><br></div><div><strong>Reference</strong>:</div><div>Kilgour P and Dixon-Jain P (2024) Groundwater Dependent Ecosystems: Remote sensing methods for regional scale mapping and characterisation of terrestrial ecosystems. Record 2024/32. Geoscience Australia, Canberra. <a href="https://dx.doi.org/10.26186/149377">https://dx.doi.org/10.26186/149377</a></div>
Parent Information
Extents
[-26, -11, 129, 138]
Reference System
Geocentric Datum of Australia 1994 / geodetic (EPSG: 6283)
Spatial Resolution
Service Information
Associations
Association Type - informed
Hydrogeology and groundwater systems of the South Nicholson and Georgina basins, Queensland and Northern Territory
eCat Identifier - 149367,
UUID - 11f9f1ef-41d6-47d2-b9c8-6090aa18f307
Association Type - operatedOnBy
South Nicholson - Georgina Basin Groundwater Dependent Ecosystems Imagery WMS
eCat Identifier - 149831,
UUID - 7d047032-12fd-4140-a626-3156bcdd4774
Association Type - operatedOnBy
South Nicholson - Georgina Basin Groundwater Dependent Ecosystems Imagery WCS
eCat Identifier - 149832,
UUID - 93ee5157-d823-4b46-9dc3-136c76d3a492
Association Type - operatedOnBy
South Nicholson - Georgina Basin Groundwater Dependent Ecosystems Imagery WMTS
eCat Identifier - 149833,
UUID - 2bb7da11-2fe9-4581-9929-893563886721
Downloads and Links
Source Information