Between the tides: Modelling the elevation of Australia's exposed intertidal zone at continental scale

摘要: Abstract The intertidal zone represents a critical transition between marine and terrestrial ecosystems, supporting complex mosaic of highly productive biologically diverse habitats. However, our understanding these important coastal environments is limited by lack spatially consistent topographic data, which can be extremely challenging costly to obtain at continental-scale. Satellite remote sensing an resource for monitoring extensive zones. Previous approaches modelling the elevation using earth observation (EO) data have been restricted small study regions or relied on manual image interpretation, thus limiting their ability applied consistently over large geographic extents. In this study, we present automated open-source approach generate satellite-derived 15,387 km2 terrain across entire Australian coastline. Our combines global tidal with 30-year time series archive spectrally calibrated Landsat satellite managed within Digital Earth Australia (DEA) platform. resulting National Intertidal Elevation Model (NIDEM) dataset provides unprecedented three-dimensional representation Australia's vast exposed 25 m spatial resolution. We validate model against LiDAR, RTK GPS multibeam bathymetry datasets, finding that modelled elevations are accurate sandy beach (±0.41 m RMSE) flat (±0.39 m RMSE). performance was least (±2.98 m rocky shores reefs other extreme variable regimes. discuss key challenges associated including biased observations from sun-synchronous satellites, suggest future directions improve accuracy utility continental-scale modelling. tidally-influenced globally, addressing gap availability sub-tidal data.