Directory of Important Wetlands in Australia (DIWA) Spatial Database including Wetlands Type and Criteria

Abstract

This dataset and its metadata statement were supplied to the Bioregional Assessment Programme by a third party and are presented here as originally supplied.

This is a polygon coverage representing the wetlands cited in the "A Directory of Important Wetlands in Australia" Third Edition (EA, 2001), plus various additions for wetlands listed after 2001. This dataset includes attribute information showing the wetlands type and criteria for listing for each wetland.

The public version which does not include wetland type is available for download at https://data.gov.au/data/dataset/6636846e-e330-4110-afbb-7b89491fe567

This coverage is a compilation of various data sources and has been collected using a variety of methods. This dataset should therefore be used as an indicative guide only to wetland boundaries and locations. The data has been collated by the Australian Government Department of the Environment from various datasets including those supplied by the relevant State agencies.

Attributes in the dataset include:

WNAME: the name of the wetland site as listed in the Directory.

REFCODE: an individual reference number including a cross reference to the State in which it occurs. The first 2-3 characters relate to the State or Territory of origin followed by the 3 digit sequential wetland numeric code. (eg. "NSW001": NSW=New South Wales; 001=wetland number).

WET_TYPE: The wetland type code. Definitions are shown below.

CRITERIA: The criteria for listing code. Definitions are shown below.

WETLAND TYPE CODES:

A-Marine and Coastal Zone wetlands

1. Marine waters-permanent shallow waters less than six metres deep at low tide; includes sea bays, straits

2. Subtidal aquatic beds; includes kelp beds, seagrasses, tropical marine meadows

3. Coral reefs

4. Rocky marine shores; includes rocky offshore islands, sea cliffs

5. Sand, shingle or pebble beaches; includes sand bars, spits, sandy islets

6. Estuarine waters; permanent waters of estuaries and estuarine systems of deltas

7. Intertidal mud, sand or salt flats

8. Intertidal marshes; includes saltmarshes, salt meadows, saltings, raised salt marshes, tidal brackish and freshwater marshes

9. Intertidal forested wetlands; includes mangrove swamps, nipa swamps, tidal freshwater swamp forests

10. Brackish to saline lagoons and marshes with one or more relatively narrow connections with the sea

11. Freshwater lagoons and marshes in the coastal zone

12. Non-tidal freshwater forested wetlands

B-Inland wetlands

1. Permanent rivers and streams; includes waterfalls

2. Seasonal and irregular rivers and streams

3. Inland deltas (permanent)

4. Riverine floodplains; includes river flats, flooded river basins, seasonally flooded grassland, savanna and palm savanna

5. Permanent freshwater lakes (> 8 ha); includes large oxbow lakes

6. Seasonal/intermittent freshwater lakes (> 8 ha), floodplain lakes

7. Permanent saline/brackish lakes

8. Seasonal/intermittent saline lakes

9. Permanent freshwater ponds ( 8 ha)

10. Ponds, including farm ponds, stock ponds, small tanks (generally

Purpose

State agency contributors include the Queensland Environmental Protection Authority, NSW Department of Environment and Conservation and the Victorian Department of Sustainability and Environment.

For the identification of wetland boundaries or locations in regard to the compliance of activities with relevant State legislation, the relevant State authority should be contacted to obtain the most recent and accurate wetland boundary information available.

The criteria for the definition of a wetland used in this dataset is that adopted by the Ramsar Convention, namely: "areas of marsh, fen, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh, brackish or salt, including areas of marine water the depth of which at low tide does not exceed six meters."

Dataset History

This dataset and its metadata statement were supplied to the Bioregional Assessment Programme by a third party and are presented here as originally supplied.

This version of the Directory of Important Wetlands has been developed to include information regarding wetland type and criteria, which allows greater access to wetland information for non-technical users of this dataset. This version of the Directory contains the same wetland boundaries as the full dataset maintained by the Department, but has been dissolved to a multipart polygon coverage on fileds WNAME (Wetland Name) and REFCODE (Reference Code). This has reduced the total number of records in the attribute table from around 30 000 to around 900.

The wetland type and criteria for listing codes have been added to the attribute table to allow users of this dataset to identify important ecological characteristics of each wetland without having to seperately refer to the full Directory of Important Wetlands textual database maintained within the Department as an oracle database.

The full textual database giving further detals on each wetland can be accessed on the internet at http://www.environment.gov.au/water/wetlands/database/index.html

The coverage has been largely derived from the TOPO250K.WATERBOD coverage (AUSLIG, 1992).

A significant portion of some of the wetland boundaries for each state have also been supplied directly from the relevant state agencies. These include the QLD Environmental Protection Agency, NSW Department of Environment and Conservation, and the Victorian Department of Sustainability and Environment.

Data supplied from State agencies may have been collected using different collection methods. These may include remotely sensed images and digitized boundaries from topographic maps or aerial photos.

For the identification of wetland boundaries or locations in regard to the compliance of activities with relevant State legislation, the relevant State authority should be contacted to obtain the most recent and accurate boundary information available.

In general the accuracy of wetland boundaries may be taken to be approximately +/- 250m in most cases.

In considering the accuracy of the wetland boundaries, users of this data should be aware of the dynamic nature of wetland boundaries and their likelihood of experiencing significant alteration over time due to climatic conditions.

Additional datasets used in compiling the Directory of Important Wetlands spatial data include:

Collaborative Australian Protected Areas Database CAPAD (Version 2.0, 1998)

National Estate, Important Wetlands Tasmania (WETLANDSREP97)

BUFFERED CENTROIDS: derived from coordinates contained in the Wetlands Inventory 2nd Ed. (ANCA, 1996) & 3rd Ed. (EA, 2001).

Location of Cook Island Nature Reserve off the North NSW coast updated to match NSW Dept of Environment and Climat Change data.

Quality

Scope: Dataset

External accuracy:

+/ - 250m can be assumed for most cases.

This dataset should be used only to indicatively locate wetland boundaries or approximate locations.

The data has been compiled from various sources and therefore mapping methodologies for wetlands is variable across State jurisdictions and over time.

In considering the accuracy of the wetland boundaries, users of this data should be aware of the dynamic nature of wetland boundaries and their likelihood of experiencing significant alteration over time due to climatic conditions.

Non Quantitative accuracy:

Most refcode attributes have been checked against the Directory of Important Wetlands. Refcode accuracy assumed to be 99% correct.

Most wname attributes have been checked against the Directory of Important Wetlands. wname accuracy assumed to be 99% correct.

Conceptual consistency:

Wetland boundaries (minimum sample of 1 in 5) are visually compared to various datasources (e.g. streamlines and topographic data) to ensure approximate accuracy when updates are received by the Department.

All wetlands are attributed with a unique reference code (REFCODE).

Some wetlands may be located only by approximate centroid points until data updates are received.

NSW wetlands supplied t in March 2004 are derived from Kingsford et. al, 'The Distribution of Wetlands in New South Wales', NSW NPWS.

NSW wetlands supplied t in March 2004 have been checked by NSW DEC against 100K and 250K topo mapsheets, Auslig waterbody data (1994) and 25K topo maps and aerial photos along coastal areas. (see 2003, Kingsford et. al, 'The Distribution of Wetlands in New South Wales', NSW NPWS).

QLD wetlands supplied by QLD EPA in June 2005 have had polygons attributed as 'exclusions' removed from this dataset to ensure that unlabelled maps do not misrepresent the extent of Directory wetlands.

Attributes of WET_TYPE and CRITERIA correspond wiht those supplied from state agenceis and inclued in the online textual database of wetlands accessed at http://www.environment.gov.au/water/wetlands/database/index.html .

Completeness omission:

99% Complete as of August 2005, Coverage will be updated and rebuilt as States/Territories provide full wetland boundaries.

Dataset Citation

Department of the Environment (2010) Directory of Important Wetlands in Australia (DIWA) Spatial Database including Wetlands Type and Criteria. Bioregional Assessment Source Dataset. Viewed 31 May 2018, http://data.bioregionalassessments.gov.au/dataset/e0e4b50c-029b-4b7a-b0f8-592c24fc2ac9.