Satellite data for coastal erosion and shoreline change in Australia
By Mazdak Ghasemi · Last checked 22 October 2026
Which satellite data is best for mapping coastal erosion in Australia?
A long Landsat record, corrected for tides. Digital Earth Australia's Coastlines maps the typical position of Australia's coastline at mean sea level for every year since 1988 from Landsat 5, 7, 8 and 9, with rates of change every 30 m along non-rocky coasts and a stated accuracy of 7.3 m (mean absolute error). NSW's 2025 statewide coastal hazard assessment used it alongside CoastSat.
Which data to use
| Data | Resolution | Revisit | Record | Use |
|---|---|---|---|---|
| DEA Coastlines | Rates every 30 m; 7.3 m mean absolute error | Yearly | From 1988 | Annual shorelines and rates of change for Australia |
| Landsat 8 and 9 | 30 m | 16 days each, 8 together | From 2013 | Recent shorelines, consistent with the archive |
| Landsat 5 and 7 archives | 30 m | Archive | 1984 to 2024 | The long record |
| Sentinel-2 | 10 m | 5 days | From June 2015 | Finer detail for recent years |
How it is done
- Gather every available image of the coast for the period.
- Model the tide for each image and drop those taken near high or low tide; DEA Coastlines removes observations outside 50% of the observed tidal range.
- Extract a typical shoreline for each year and calculate rates of change along the coast.
Limits to know
- Annual shorelines do not show short-term changes such as individual storms.
- Intertidal flats, persistent cloud and large tidal ranges reduce accuracy, and rocky coasts are flagged.
- NSW notes that satellite trends may reflect multi-decadal climate variability or human interventions as well as erosion.
- Landsat 7 scenes since June 2003 have gaps from the Scan Line Corrector failure.
Who does this in practice
- Digital Earth Australia's Coastlines maps Australia's coastline at mean sea level for every year since 1988.
- NSW's 2025 coastal erosion and inundation assessment analysed DEA Coastlines and CoastSat across 758 beach sectors, about 90% of the state's sandy shorelines.
What Terrascout returns
The real result for “Monitor coastal erosion along the Gold Coast QLD shoreline over the last 10 years” (Gold Coast, QLD), captured on 22 October 2026: the top 2 of 6 sources.
| # | Source | Type | Resolution | Cost | Fit |
|---|---|---|---|---|---|
| 1 | Sentinel-2 MSI | Optical | 10 m | No data fee | 98 |
| 2 | Landsat 8 OLI/TIRS | Optical | 30 m | No data fee | 94 |