Enabling the public sector to save money, innovate and make more effective policy decisions by using space technology and data

Case Study: Satellite Oceanographic Consultants and National Oceanography Centre – Sea Level SpaceWatch

General Information

  • Provider: Satellite Oceanographic Consultants Ltd. and National Oceanography Centre
  • Technology utilised: Earth observation (EO)
  • Thematic area: Natural Hazards
  • End user(s): Relevant UK Government bodies and agencies e.g. The Committee on Climate Change, Environment Agency, Natural Resources Wales, Scottish Environmental Protection Agency, Department of Agriculture and Rural Development – Northern Ireland
  • Website: www.satoc.eu/projects/sealevelsw

Year

  • 2015

Project Background / Overview

This project set out to develop a prototype sea level monitoring service for UK seas to assess sea level variability using space-borne altimeter data combined with tide gauge data. The intention was to devise a service which would be able to:

  • Advise the UK’s Committee on Climate Change in the production of their 5 yearly Climate Change Risk Assessment
  • Support the planning of national flood defences and adaptation plans, and the maintenance of coastal habitats
  • Provide supplementary information of seasonal and regional variations in sea level to the UK Climate Projections – following on from the UK Climate Predictions 2009 (UKCP09) and the Marine Climate Change Impacts Partnership (MCCIP)

This would require the following information to be gathered:

  • Regional trends in mean sea level around the UK
  • Regional trends in peak tides
  • Number of times tide level thresholds are exceeded
  • Number of time coastal defences are breached per year and where this occurs
  • Comparison of current trends in sea level with future projections

New leaps have recently been made in the calculation of coastal altimetry from satellite data. The National Oceanography Centre is the global leader in this field. With this advancement it will be possible to recover altimetry data along the coastal strip of the UK for the last 20 years.

This information would provide end users with a much greater understanding of mean sea level change which will strongly govern future flood probabilities, and of observed sea level trends vs predicted trajectories. This would allow more timely and insightful decisions to be made on when and where to direct investments to maximise the reduction in unacceptable flood risk.

The aim of the Sea Level Space Watch service was to make this data available to the end users. It provided access to 8 years’ worth of altimetry data from Envisat Altimeter and generated a range of data products which are free to download.

Lessons Learned

Data was acquired for an 8 year period. Analysis was conducted which has already yielded new insights, such as a link between open ocean sea level with shelf seas and the coastal zone; regional variability in trends and annual cycles; and the timing of peak annual cycles occurring more than a month later in the West and North of the UK. However, a longer time series should be acquired, and verified against tide gauge data to better understand the measurements.

Costs and Benefits

The set-up costs to make the Sea Level Space Watch an operational service were estimated to be in the region of £70 to 100k, with an annual operating cost of ~£20k.

These costs would be recouped if the service could provide a 0.01% improvement in the efficiency of decisions on the investment in coastal flooding infrastructure.

Next Steps

The potential value of this service has been widely recognised and generated considerable interest amongst its intended end users.

To better meet the end users’ needs development should focus on validating the satellite product, establishing a supply chain to process the data and combining EO and in-situ (tidal gauge) data. This would also need to be supplemented with the recovery of more of the data archive to provide a longer time series to produce more robust statistics. It has been estimated that this could be achieved with 6 to 12 months of development. At the end of this development phase a business case would be created to turn this into an operational service which targets co-funding from the end users.

This service could also be extended for coastal regions across Europe and beyond, especially in flood sensitive areas which currently lack accurate ground based data. It is anticipated that there are various funding sources available to explore such applications.