Dataset Number 2693 Dataset Title River Murray Flood 2022 Status Published Metadata Maintained by DEW INFO

Description Category Natural Hazards Theme Flood Keywords and Qualifiers Dataset Type Spatial Description This coverage shows the extent of the land flooded during the 2022/2023 flood event for the River Murray. Dataset Use The 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. SDE Feature Class Name TOPO.MurrayFlood2022 Projection/ Coordinate System LAMBERT

Custodian Data Authority Data Authority Department for Environment and Water Data Authority Name Matthew Ward Director, Science and Information Data Manager Matt Royal Manager Geospatial Environmental Data & Info Department for Environment and Water Matthew.Royal@sa.gov.au 8124 4880 Subject Matter Expert Gabrielle Eckert Flood Management Officer (GIS) Department for Environment and Water Gabrielle.Eckert@sa.gov.au (08) 8124 4771 Data Integrity Officer Rudi Luce Coordinator Spatial Data Maintenance Department for Environment and Water Rudi.Luce@sa.gov.au (08) 8463 3876

Data Provider Data Provider Department for Environment and Water

Data Quality Lineage The 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 Completeness This 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 Accuracy The 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. Method / Capture Scale Method Capture Scale Comment Satellite imagery 1:5000 Manual correction of satellite derived inundation extent

Tables

Field Description

Geographic Extent Extent Name River Murray Min Easting or Longitude 138.5 Min Northing or Latitude -36.25 Max Easting or Longitude 141 Max Northing or Latitude -33.75

Dataset Status Initially Acquired 27-JAN-2023 Last Updated 04-APR-2023 Update Frequency Not Planned Maintenance Method Not maintained Metadata Created 31-MAR-2023 If copied, source dataset Metadata updated 12/APR/24 env\bpellegrino Authorised 05/APR/23 env\jcameron Metadata Retired

Security Classification ISMF Classification OFFICIAL ISMF Integrity I2 - MODERATE Requirement ISMF Availability A2 - MODERATE Requirement AusGOAL Licensing Classification CC BY (Attribution) Attribution Further considerations for supply of dataset No

Operator Notes

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