Coastal Sediment Grain Size Estimates on Gravel Beaches Using Satellite Synthetic Aperture Radar (SAR)

Mann, Sophie; Novellino, Alessandro; Hussain, Ekbal; Grebby, Stephen; Bateson, Luke; Capsey, Austin; Marsh, Stuart

Abstract

Coastal sediment grain size is an important factor in determining coastal morphodynamics. In this study, we explore a novel approach for retrieving the median sediment grain size (D50) of gravel-dominated beaches using Synthetic Aperture Radar (SAR) spaceborne imagery. We assessed this by using thirty-six Sentinel-1 (C-band SAR) satellite images acquired in May and June 2022 and 2023, and three NovaSAR (S-band SAR) satellite images acquired in May and June 2022, for three different training sites and one test site across England (the UK). The results from the Sentinel-1 C-band data show strong positive correlations (R2≥0.75) between the D50 and the backscatter coefficients for 15/18 of the resultant models. The models were subsequently used to derive predictions of D50 for the test site, with the models which exhibited the strongest correlations resulting in Mean Absolute Errors (MAEs) in the range 2.26–5.47 mm. No correlation (R2 = 0.04) was found between the backscatter coefficients from the S-band NovaSAR data and D50. These results highlight the potential to derive near-real time estimates of coastal sediment grain size for gravel beaches to better inform coastal erosion and monitoring programs.

Citation

Mann, S., Novellino, A., Hussain, E., Grebby, S., Bateson, L., Capsey, A., & Marsh, S. (2024). Coastal Sediment Grain Size Estimates on Gravel Beaches Using Satellite Synthetic Aperture Radar (SAR). Remote Sensing, 16(10), Article 1763. https://doi.org/10.3390/rs16101763

• Journal Article Type: Article
• Acceptance Date: May 11, 2024
• Online Publication Date: May 16, 2024
• Publication Date: 2024-05
• Deposit Date: May 17, 2024
• Publicly Available Date: May 17, 2024
• Journal: Remote Sensing
• Electronic ISSN: 2072-4292
• Publisher: MDPI
• Peer Reviewed: Peer Reviewed
• Volume: 16
• Issue: 10
• Article Number: 1763
• DOI: https://doi.org/10.3390/rs16101763
• Keywords: SAR; gravel beach; coarse sediment; coasts; sediment grain size; Sentinel-1; NovaSAR-1
• Public URL: https://nottingham-repository.worktribe.com/output/34868479
• Additional Information: Received: 10 April 2024 Revised: 1 May 2024 Accepted: 11 May 2024; Citation: Mann, S.; Novellino, A.; Hussain, E.; Grebby, S.; Bateson, L.; Capsey, A.; Marsh, S. Coastal Sediment Grain Size Estimates on Gravel Beaches Using Satellite Synthetic Aperture Radar (SAR). Academic Editors: Luis Gómez Déniz