River Murray Flood 2022

Dataset Number2693
Dataset TitleRiver Murray Flood 2022
CustodianData Authority: Department for Environment and Water
Data Provider: Department for Environment and Water

Description

DescriptionThis coverage shows the extent of the land flooded during the 2022/2023 flood event for the River Murray.
UsageThe 2022 River Murray Flood Extent product has been derived from high resolution satellite SPOT 6/7 imagery captured during the River Murray flood event during peak flow. It provides a detailed spatial extent of where flood waters likely reached during the event. Several minor issues with the extent have been observed, mostly to do with delineating the extent of water in grassed/cropping areas, inundated vs saturated areas and densely built locations. These issues have been mostly corrected using manual editing methods and validated with the original SPOT image a1 1:5000 scale. Other minor artefacts seen in the product have been corrected where possible and will likely not detract from the overall quality of the dataset across most of the floodplain.

Timing of image capture in relation to the flood peak (which progressively moved down the River to the Lower Lakes from late December 2022 to early February 2023) was carefully considered during the image capture phase. Most areas have been captured at or near peak, which provides greater confidence in the extent. Where sections of the River and Lower Lakes have been captured off peak (Overland Corner (Lock 3) to Morgan, Mannum to Wellington and western Lake Alexandrina to the Barrages), the extent may be underrepresented. This needs to be considered when using the data for certain applications e.g. hydraulic/hydrological modelling and large scale applications.

Data Quality

LineageThe 2022 River Murray flood extent was captured in 2023 by Geoimage Pty Ltd by deriving a vector extent from the application of a Normalised Difference Water Index (NDWI) from pan-sharpened 1.5m spatial resolution multispectral SPOT 6/7 imagery.

Satellite imagery was collected at locations of peak flow along the River Murray on:

- 26 December 2022

- 31 December 2022

- 6 January 2023

- 8 January 2023

- 12-14 January 2023

- 26-27 January 2023

CompletenessThis dataset is complete for the River Murray from the state border to the Murray Mouth and includes Lake Alexandrina and Lake Albert. The Coorong is complete only to Taratap.
Positional AccuracyThe SPOT 6/7 imagery was orthorectified using ground control points from aerial imagery. Imagery and the derived inundation extent layer has an overall horizontal accuracy of +/-1.5m (CE90).

The inundation extent layer was manually edited by the Geospatial, Environmental Data & Information Unit at 1:5000 scale to improve the delineation accuracy by comparing it to the multispectral satellite imagery and correcting the extent where required. No ground validation has been undertaken.

Geographic Extent

Extent NameRiver Murray
Min Easting or Longitude138.5
Min Northing or Latitude-36.25
Max Easting or Longitude141
Max Northing or Latitude-33.75

Dataset Status

Initially Acquired27-JAN-2023
Last Updated04-APR-2023
Update FrequencyNot Planned
Maintenance MethodNot maintained
AusGOALCC BY (Attribution)

Attributes

TableNameField AliasData TypeDescription
Polygon Attribute TableACQ_DATE DateAcquisition date of satellite imagery used to derive flood extent.

Contact Information

OrganisationDepartment for Environment and Water
Information
Postal AddressGPO Box 1047

ADELAIDE
SA 5001
EmailDEWNR.Mapland@sa.gov.au