With a coastline of approximately 7400 km and projected changes in sea levels due to climate change, the island of Ireland is highly susceptible to coastal erosion.
Coastal erosion is an urgent problem affecting local communities, businesses and ecosystems. This is particularly the case in Eastern and Southern areas that are dominated by soft sediment. Monitoring the entire coastline for signs of erosion is a mammoth task, but it is one that Earth Observation technologies can greatly assist with. Mallon colleague Sandra Molloy has created the following images of Coastal Erosion along the Wexford coast.
A Snapshot of Coastal Erosion on the Wexford Coast
According to the Environmental Protection Agency, about 20% of Ireland’s coastline is at risk of coastal erosion. The risks are only being exacerbated due to the impact of climate change, such as rising sea levels and increased storm intensities. Using satellite data, Mallon examined an area of the Wexford coast experiencing coastal erosion.
Satellites are ideally suited to monitoring coastal erosion as they enable a user to monitor large areas quickly and track changes over specific time periods. The following maps were created using images from the Landsat and Sentinel–2 satellites.
For the maps, the coastline was accurately determined by using the Normalised Difference Vegetation Index (NDVI) values of 0.2 or greater, as these generally represent vegetated areas. Lower positive values tend to represent more barren land, such as gravel and sand, which are more likely to be impacted by tides.
Landsat Maps
The two images below show part of the Wexford coast taken by Landsat in 1984 and 2024. The spatial resolution is 30m. The 1984 coastline and the present–day coastline have been delineated and show erosion along most of this coast over the 30–year period.
Sentinel–2 Maps
These Sentinel–2 images are of the same area along the Wexford coast, with the coastline from 2017 and 2024 delineated. The spatial resolution is 10m, and in some parts of the coast, erosion has been greater than 10m in just 7 years.
How can Earth Observation Help Tackle Coastal Erosion?
As the maps above show, it is possible to track and identify areas where coastal erosion has occurred using Earth Observation imagery and data. This can all be done remotely and on a large scale, allowing a complete picture of areas affected by coastal erosion to be created.
Such maps can inform decision–making, help in the early identification of affected areas, and lead to better resource management, including the adoption of protection measures in important or highly populated areas.
Further Information
For further information about the methods used to produce the maps above or to discuss your Earth Observation requirements, contact us below.
