Lismore Floods, March 2025
Between 6 and 10 March 2025, Tropical Cyclone Alfred brought heavy rainfall to Lismore, NSW. The Wilsons River peaked at 9.31 m, just below the major flood level of 9.70 m. This page shows which satellite sensors Terrascout ranks for mapping a flood like this one.
Lismore City Council records that Tropical Cyclone Alfred brought heavy rainfall to Lismore between 6 and 10 March 2025, and that the Wilsons River peaked at 9.31 m, just below the major flood level of 9.70 m. Evacuation orders were issued, the NSW SES carried out rescues as roads became impassable, and power was disrupted to thousands of properties. For comparison, the highest flood on record in Lismore was on 28 February 2022, when the level reached 14.4 m; the record before that was 12.11 m.
For the Wilsons River catchment and a flood-mapping objective, Terrascout's matching engine ranks Sentinel-2 MSI and Sentinel-1 C-SAR almost level at the top (fit 94 and 93 out of 100), followed by NSW aerial imagery and LiDAR elevation data. Sentinel-1 is a radar sensor, so it sees through cloud, which is normal during a flood. Sentinel-2 is optical: it revisits more often but needs a clear sky, so it is most useful for comparing the area before and after the event. The elevation data matters because flood modelling needs the shape of the ground, not only images of the water.
This page does not show flood-extent imagery or an analysis of the event. It shows which data a flood-mapping project over this area would draw on, and why.
How Terrascout would have observed it
Top sensor matches from the Terrascout matching engine.
| # | Sensor | Provider | Fit |
|---|---|---|---|
| 1 | Sentinel-2 MSI Free and open access — no acquisition cost; Sensor is fully operational | European Space Agency | 94 |
| 2 | Sentinel-1 C-SAR Free and open access — no acquisition cost; Sensor is fully operational | European Space Agency | 93 |
| 3 | NSW Aerial Imagery Free and open access — no acquisition cost; Sensor is fully operational | Department of Customer Service — Spatial Services (New South Wales) | 87 |
| 4 | OpenTopography Global LiDAR Free and open access — no acquisition cost; Sensor is fully operational | OpenTopography Facility | 86 |
| 5 | ELVIS LiDAR DEMs Free and open access — no acquisition cost; Sensor is fully operational | Geoscience Australia | 86 |
Fit (0–100) weighs resolution against the brief (30%), cost (25%), coverage of the area (20%), revisit time (15%), and sensor status plus published evidence for the task (10%). How matching works
ML training-data fitness
How well this sensor stack would support training a machine-learning model for this use case.
Aggregated from 4 dimensions below.
- Temporal Continuity100%
61 usable scenes/year vs 12 needed (SAR: all-weather advantage)
- Resolution Match100%
5.0 pixels across feature (50m) — excellent
- Class Balance50%
Estimated from use case characteristics
- Spectral Suitability75%
No specific band requirements for this use case.
What people asked the Copilot
Curated questions and answers about monitoring this event.
- Radar sensors such as Sentinel-1 C-SAR work through cloud and at night. Floods usually arrive with heavy cloud, which blocks optical sensors such as Sentinel-2.
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