Near Real-Time Monitoring of Muddy Intertidal Zones Based on Spatiotemporal Fusion of Optical Satellites Data

Abstract

The investigation of the evolution of intertidal zones is a significant and extensively discussed subject in estuary and coastal research, both nationally and internationally. Recent advances in real-time global satellite products, such as GOCI, provide a potential approach for monitoring intertidal zones by utilizing waterline inversion based on spatial distribution processes. While these products offer the potential for monitoring intertidal zones through waterline inversion based on spatial distribution processes, they often suffer from coarse spatial resolution that smooths critical spatial heterogeneity. To overcome this limitation, a flexible spatiotemporal fusion model was employed to generate hourly time-series images with a spatial resolution of 10 m. This was achieved by combining Sentinel-2 satellite data (10 m spatial resolution; five-day revisit frequency) and GOCI-II data (500 m spatial resolution; 1-h revisit frequency). The resulting fusion images were used to construct an intertidal pseudodigital elevation model (DEM) by extracting waterlines and incorporating tidal-level information. The accuracy of the DEM was validated using surveyed real-time kinematic and drone data, with a root-mean-square error of 0.28 m. The analysis of the annual accretion and erosion evolution in the intertidal zone for the year 2023 revealed significant erosion in the central part of the zone, with a maximum erosion depth of 1 m at the bottom. This study contributes to the understanding of the response processes and mechanisms of the intertidal zone to natural and human disturbances, thus supporting coastal planning projects related to the intertidal zone.

Keywords

• Environment monitoring
• flexible spatiotemporal data fusion (FSDAF)
• GOCI-II
• muddy intertidal zone
• optical satellites
• spatiotemporal fusion