Predicted Seabed Gravel Content for Darwin Harbour Region

A 10-meter resolution raster grid provides spatially continuous predictions of seabed gravel content for the Darwin and Bynoe Harbour regions in northern Australia. The dataset was created by Geoscience Australia, the Australian Institute of Marine Science, and the Northern Territory Government's Department of Environment and Natural Resources, using surveys conducted between 2011 and 2017. Predictions are based on 395 physical samples and 14 environmental variables derived from multibeam sonar data.

Use Cases

• Model sediment transport dynamics by analyzing the spatial distribution of predicted gravel content across the harbour seafloor.
• Classify benthic habitats by integrating the gravel content predictions with other seabed substrate layers like mud or sand.
• Validate and improve geological models by comparing the 10m resolution predicted gravel grid with new point sample data.
• Assess the impact of coastal development by establishing a baseline of gravel distribution for change detection over time.

Strengths

• High predictive accuracy with a VEcv (Validation Error) of 59% for gravel content.
• Demonstrated 68.4% improvement in predictive accuracy over the commonly used Inverse Distance Weighting (IDW) method.
• Spatially continuous predictions at a fine 10-meter grid resolution for the entire harbour region.

Limitations

• Predictions are based on a limited set of 395 physical ground-truth samples for model training.
• Data gaps (absences) exist in the predictions where the required 14 predictive environmental variables were unavailable.
• The underlying survey data is from 2011-2017, which may not reflect recent seabed changes.

Provenance

Source

Compilation of multiple surveys by Geoscience Australia, Australian Institute of Marine Science, and the Northern Territory Government.

Collection Method

Predictions generated from 395 samples and 14 environmental variables derived from high-resolution multibeam sonar bathymetry and backscatter data.

Time Range

Surveys conducted between 2011 and 2017.

Freshness

Dataset metadata was last updated in April 2026, though the core survey data is from 2011-2017.

Geography

Greater Darwin Harbour and Bynoe Harbour region, northern Australian marine margin.