RT journal article
T1 Assessing Satellite-Derived Shoreline Detection on a Mesotidal Dissipative Beach
A1 Cabezas Rabadán, Carlos
A1 Almonacid Caballer, Jaime
A1 Benavente González, Javier
A1 Castelle, Bruno
A1 Río Rodríguez, Laura del
A1 Montes Pérez, Juan Bautista
A1 Palomar Vázquez, Jesús
A1 Pardo Pascual, Josep E.
A2 Ciencias de la Tierra
K1 shoreline definition
K1 Sentinel-2
K1 beach monitoring
K1 water indexes
K1 videomonitoring
K1 SAET
AB The accuracy and robustness of the shoreline definition from satellite imagery on differentcoastal types are crucial to adequately characterising beach morphology and dynamics. However,the generic and widespread application of satellite-derived shoreline algorithms is limited by thelack of robust methods and parameter assessments. This work constitutes a quantitative and comprehensiveassessment of the satellite-derived waterlines from Sentinel-2 by using the novel SAET tool(Shoreline Analysis and Extraction Tool) on the exposed and mesotidal beach of La Victoria (Cádiz,SW Spain). The diverse parameters available in SAET, such as water indexes, thresholding methods,morphological filters, and kernel sizes, were combined to define water/land interface positions thatwere compared against coincident video-derived waterlines. Satellite-derived waterline errors arefound to be affected by extraction parameters, as well as by the oceanographic and morphologicalconditions at the time of the image acquisition. The application of a morphological erosion filter onthe water mask, which tends to shift the extracted waterline seawards and reduce bias, is the bestsolution at the dissipative site of La Victoria Beach. Moreover, using a 3 × 3 kernel size consistentlyshows higher accuracies than a larger kernel. Although there was no parameter combination showingthe best skill for all dates, the employment of the Automated Water Extraction Index for images withno shadows (AWEInsh) with a threshold = 0, erosion morphological filter, and 3 × 3 kernel was,overall, the best combination of extraction parameters for this beach (average waterline RMSE of5.96 m). The combination of the Modified Normalised DifferenceWater Index (MDNWI) with theOtsu thresholding also led to similar positions of the resulting waterlines and offered good accuracies.In line with other recent research efforts, our work stresses the lack of generic shoreline extractionsolutions that can be applied automatically at a global level and the necessity to adapt and validatethe extraction methodologies to the different types of coastlines.
PB MDPI
SN 2072-4292
YR 2024
FD 2024
LK http://hdl.handle.net/10498/32407
UL http://hdl.handle.net/10498/32407
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 10-nov-2026