OCEANIDS — Coastal Change from Satellites

Coastal Change from Satellites

This repository contains 40 years of tidally-corrected shoreline change time-series for sandy coastlines along 4 locations in Europe:

• The island of Crete, Greece: 81 sandy beaches mapped
• The port of Heraklion, Greece: 2 beaches mapped
• The island of Corfu, Greece: 1 beach mapped
• The port of Malaga, Spain: 2 beaches mapped
• The region of Bretagne, France: 1 beach mapped

Method

The timeseries of shoreline change from 1984 to 2025 were extract with the CoastSat shoreline mapping toolbox.

CoastSat was used to map shoreline changes on Landsat 5, Landsat 7 and Landsat 8 imagery between 1984 and 2025. The Coastsat toolbox is publicly available at https://github.com/kvos/CoastSat and described in Vos et al. 2019, https://doi.org/10.1016/j.envsoft.2019.104528. The time-series of shoreline change were tidally-corrected along cross-shore transects using tide levels from a global tide model (FES2022) and a satellite-derived estimate of the beach slope (as described in Vos et al. 2020, "Beach slopes from satellite-derived shorelines", https://doi.org/10.1029/2020GL088365). 

Data structure

One folder per site is provided with the following subfolders:

• /timeseries: timeseries of coastal change along each transect in .CSV files, for each date the beach width in metres is reported, this is the horizontal distance from the non-erodible line to the waterline.
• /geojson: contains the geospatial layers to locate the timeseries:
  •  coastal_change_transects.geojson: this layer contains the cross-shore transects which are spaced 100 m along each beach and start at a non-erodible point. Each transect has the linear trend (in m/year) of coastal change.
  • coastal_change_baseline.geojson: this layer contains the non-erodible line use as baseline to compute the timeseries of beach width.
  • coastal_change_polygon.geojson: area of interest used to download the satellite imagery for each site
• /plots: plots of the timeseries in .jpg format, which can be integrated in reports. They show the raw timeseries, seasonal averages, long-term trends and latest position of the shoreline.

For any questions on the data, contact Kilian Vos at kilian.vos@ohb-ds.de