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Metadata : Wetlands of Simpson Desert, Northern Territory |
Index:
Metadata Details:
Name:AS/NZS ISO 19115 Geographic Information - Metadata, ANZLIC Metadata Profile
Version:1.0
Date Metadata Extracted:2024-04-27
Date Metadata Last Updated:2019-11-06
Current URL (HTML format) : http://www.ntlis.nt.gov.au/metadata/export_data?type=html&metadata_id=95F2402C3A1135E1E0530101007FE1C6
Current URL (XML format) : http://www.ntlis.nt.gov.au/metadata/export_data?type=xml&metadata_id=95F2402C3A1135E1E0530101007FE1C6
Citation
ANZLIC Identifier:95F2402C3A1135E1E0530101007FE1C6
Title: Wetlands of Simpson Desert, Northern Territory
Citation Date:2018-06-30
Date Type:creation
Custodian:Department of Environment, Parks and Water Security
Description
This dataset is the basin wetlands throughout the area of the Simpson Desert that lies above the Northern Territory (NT) portion of the Great Artesian Basin (groundwater basin). Some polygons of some wetlands types (e.g. swamps, clay pans, waterholes) occur within a broader floodplain area. In these cases the floodplain is mapped as a distinct polygon that overlaps other wetland polygons. Drainage lines are not delineated in this mapping, although some drainage lines are within the areas inundated in large events. Some waterhole wetlands within drainage lines were mapped but not systematically across the area. The mapping covers most of the NT part of the Simpson Desert and includes the Pedirka Basin (geological basin). In some areas, small clay pans were not mapped for this product either because they were smaller than the minimum size (<900m2) or because there was no record of past inundation in Landsat satellite imagery. sIn eight locations there is a very high density of small clay pans (<900m2) and these have been mapped as point features in an accompanying dataset.
- biota
- geoscientificInformation
Bounding Coordinates:
- North Bounding Coordinate:-23.204
- South Bounding Coordinate:-26.004
- East Bounding Coordinate:138.018
- West Bounding Coordinate:133.897
Dataset Status
Dataset ID:
Language:English
Character Set: Latin 1
Progress:completed
Maintenance and Update Frequency:notPlanned
Data Currency Start Date:2016-01-01
Data Currency End Date:2018-06-30
Access Constraint:
Download the spatial data package (contains spatial data, maps and reports) via data.nt.gov.au/
You are licensed to use the DENR geospatial products on the terms and conditions set out in: Creative Commons Attribution 4.0 International Public License (CC BY 4.0) at: creativecommons.org/licenses/by/4.0/legalcode
If you do not agree to the terms and conditions you must not use the geospatial products.
You are free to copy, communicate and adapt the licensed material, provided that you abide by the licence terms (including Attribution) and attribute the licensed material using the statement:
Supplied by the Department of Environment and Natural Resources. Copyright Northern Territory Government.
Data Quality
Lineage:Wetland polygons were hand digitised following landform, vegetation or both boundaries observed in Google Earth. Wetlands were only digitised if past inundation was evident in the Landsat satellite image archive or other Landsat imagery. The Landsat archive analysis was provided by Jason Barnetson from NTG, who collaborated with Peter Scarth from QLDG to detect and collate inundated pixels in the Landsat TIM images between 1987 and 2014. The output analysis is the NT Count product, also known as the Northern Territory Inundation Frequency (NTIF) database. Additional remotely sensed image products were created for mapping some area. The polygon mapping and attribution was conducted by Stephen Eldridge of Desert Wildlife Service in two stages. Stage 1 commenced in 2016 included assessing various data sources, mapping methods and mapping scales. Stage 2 concluded in June 2018 applied the chosen method across the study area.
Processing steps:
Wetland features were mapped by hand digitising if a wetland landform or vegetation boundary could be discerned using Google Earth imagery and if surface water was detected in analysis of the Landsat TM satellite image archive. The archive analysis output was the NT Count product. NT Count is similar to the Water Observations from Space (WOfS) product created by Geoscience Australia. The minimum polygon size mapped was 900m2 (a Landsat pixel equal to 30m by 30m). The data was digitised in Google Earth (aided by NTIF), exported as kml files and converted to ESRI shape files using ArcGIS 10.5. A unique numbering code created for uniquely identifying wetland polygons (ID), based on a numbered mapping grid.
Positional Accuracy:Positional accuracy varies to a maximum of 50m. However, the extent of inundation in wetlands can vary greatly so that determining the outer boundary of a wetland can be a subjective mapping decision. Where the mapped boundary followed a distinct landform or vegetation edge discernible in Google Earth, the positional accuracy is expected to be within 10m in many cases.
Attribute Accuracy:Attributes are from a variety of data sources. Those with variable accuracy have been assigned confidence rankings to allow users to assess accuracy when working with the dataset. All polygons have attribute values as described in the Data Dictionary in this metadata record.
Logical Consistency:Polygon topology error (e.g. crossovers, slivers) arising during digitising have been removed. A small number of polygons overlap where smaller wetland features exist within larger features (e.g. a swamp within a floodplain). Each polygon is uniquely identified based on its location within the coverage area. Some of the large wetland polygons (e.g. lakes and floodplains) have non-wetland islands within them.
Completeness:Complete within the scope of the project: includes all basin wetlands in which water was detected in the satellite image products. Fringing areas of the Simpson Desert beyond the Great Artesian Basin were not mapped. Drainage lines were not mapped. Some waterholes are mapped but not consistently across the study area. Additional data and time would have been required to systematically delineate all waterholes. Small very rarely inundated clay pans were not mapped.
Contacts
Name Organisation Position Role Phone Fax Data Requests Officer Department of Environment, Parks and Water Security Geospatial Services Branch (on behalf of department) distributor datarequests.depws@nt.gov.au
Data Dictionary
Attribute Attribute Description Possible Code Code Description 01. OBJECT_ID Object ID 02. GRID_REF Mapping Grid Reference 03. GR_TALLY Sequential ID of polygon within mapping grid cell 04. CENTROID_X Centroid Location (Longitude) 05. CENTROID_Y Centroid Location (Latitude) 06. NAME Asset Name 07. IBRA_REG IBRA Region 08. IBRA_SUB IBRA Sub-region 09. TYPE System Type 10. TYPE_CONF System Type (confidence score) 11. AREA_m2 Area of polygon in square metres 12. SCALE Scale descriptor 13. INFLOW_REG Inundation (in-flow) Regime 14. IR_CONF Inundation Regime (confidence score) 15. CONNECTVTY Hydrological Connectivity 16. CONN_CONF Hydrological Connectivity (confidence score) 17. WDF Water Detection Frequency, from Northern Territory Inundation Frequency database 18. WDF_CAT Water Detection Frequency (Category) 19. GE_RES Google Earth Resolution at centroid location of polygon as at 01 May 2018. 20. GE_DATE Google Earth Image Capture Date at centroid location of polygon as at 01 May 2018. 21. SURV_DATA Availability of Pre-existing Wetland survey data within 100m of the polygon boundary 22. PLANT_REC Existence of Wetland Plant Records within 100m of the polygon boundary (NT Flora Atlas database) 23. PLANT_NUM Number of Wetland Plant Collections within 100m of the polygon boundary (NT Flora Atlas Database)
Supplementary Information
The mapping was part of a collaboration between the NT, South Australian and Australian governments that created and collated information about aquatic ecosystems that could potentially be impacted by utilising coal and coal seam gas resources (e.g. the Pedirka Basin coal beds). The collaborative project (now finished) was called the Lake Eyre Basin Rivers Monitoring (LEBRM) project and was co-funded by the Office of Water Science.
Water Resources Technical Report 24/2019: Mapping of Wetlands in the Northern Territory Portion of the Lake Eyre Basin (incorporating the Pedirka Geological Basin) Stage 2.
This record maintained using the NTLIS Metadata Tool