Observing Coastal Erosion from Space / / by Andres Payo

Dr Andres Payo is a coastal geomorphologist working on the Environmental Change, Adaptation and Resilience Challenge area at Keyworth, focusing on better understanding how to make our coast and estuaries more resilient to a changing human-natural environment. Here, in part one of a two-part blog, Andres explains what aspects of coastal erosion are feasible to be monitored from space and how this information is being used in BGS to build more resilient coasts and estuaries in the UK and internationally. 

Happisburgh, North Norfolk, as seen on Google Maps © Google
Happisburgh, North Norfolk, as seen on Google Maps © Google

Here at the British Geological Survey we are pretty good analysing the processes that drive coastal erosion and coastal flooding (see here how our scientists quantified the level of protection provided by beaches against cliff erosion), simulating what might happen under different human-natural future scenarios (see here how we simulated the quick erosion after defences were removed in Happisburgh) and communicating our understanding to specialist and non-specialists (see here how we use 3D and 4D model to communicate our understanding). 

This matters because a clear conclusion from the recent Special Report on the Ocean and Cryosphere in a Changing climate shows that adaptation to Sea Level Rise (SLR) will be needed, as no matter what emission reducing scenario is followed sea level will still rise. Globally, adaptation to coastal flooding and coastal erosion has the potential to reduce by a factor of 10 if we compare the expected impacts of SLR to the alternative of no adaptation. 

In the UK, the latest UK Climate Change Risk Assessment has announced flooding and coastal change risk to communities, businesses and infrastructure as the top priority needing attention over the next five years. 

Along with industry and governmental partners from the UK, Spain, Republic of Ireland and Quebec, me and my team have been successful in winning a €1.5M grant from the European Space Agency (ESA) in the form of a two-phase project (feasibility and demonstration) to monitor coastal erosion from space. BGS, as part of the Coastal Erosion Project, has the ability to add great value in managing the risk of, and preventing, coastal erosion.

Wait. Coastal erosion can be seen from space?

The sequence of images shows the red, green and blue, cloud-free satellite images from 2015 until Dec 2017

Well, yes! You will certainly be impressed by what we can see from space. For instance, the image above illustrates how the Village of Happisburgh in North Norfolk is seen from space in 10 metre resolution by the Sentinel 2 mission. 

The Coastal Change from Space Consortium brings together a group of professional satellite service providers with government bodies with an interest in monitoring coastal change. I'm leading the end-user group which is trying to answer what end users need and what is feasible to observe from space (Payo et al. 2019). End-Users enrolled in this project are either government agencies in charge of providing geoscientific advice, like the British and Republic of Ireland Geological Surveys, or ministries like the Ministry of Environment and Ecological Transition in Spain. The broader end-user community is made up of institutions in charge of monitoring coastal change, like the Regional Coastal Program in England and Wales, engineering consultant and coastal district managers. Although we are still working on the production and validation of the different products (waterlines, shorelines, bathymetries, submerged features mapping) this project has already been picked up by ESA as a success story. See here for more details on the project. 

In part two of this blog I will explain how BGS is using Earth Observation, combined with innovative non-intrusive ground observation survey methods and 4D modelling to better understand and ultimately inform how to build more resilient coastal human-natural systems in the UK and globally.