- 14th May 2019
- Posted by: Sophie Bunker
- Category: Blog
We are well represented at the Young Coastal Scientists and Engineers Conference at the University of Glasgow this week. Dr. Doug Pender is giving a keynote speech on the advances in coastal management practices. Three recent projects are also being presented by Hannah Otton, Callum Rowett and Johnny Coyle.
If you are attending the conference, please come and have a conversation with the team. Alternatively, you can read more about each project below.
Advances in coastal management
The climate is changing, research is continually advancing, but what are we as practitioners doing to make sure that these are incorporated into decision making?
Over the last few years there have been significant step changes in the way that we analyse and model coastal processes within the UK. To demonstrate and discuss these recent advances, key topics and issues will be presented, providing an overview of the coastal management in the UK.
Current techniques employed to solve specific problems in modelling, sediment management and engineering will be presented. This will be followed by an outline of the potential future direction of the industry, in response to recent changes in requirements and advances in research.
Stonehaven erosion study
Stonehaven community is at risk from coastal erosion and flooding, and the coastline is fronted by coastal defences providing crucial protection to residents. If these defences were to fail, infrastructure would be exposed to extreme wave forces resulting in significant erosion and economic damage.
1D XBeach morphodynamic modelling was undertaken to assess morphological processes within the bay and to understand the response of the beach during extreme conditions. Undefended scenarios were also simulated for a range of design conditions to simulate which assets would be at risk if the coastal defences were to fail, identifying areas likely to be at risk of erosion by 2050, 2080 and 2118.
Future of the Isles of Scilly: Flood risk in 2116
Recent UKCP18 and previous UKCP09 guidance provide UK climate change predictions, including estimated increases in sea level and changes to the offshore wave climate. Coastal managers must understand how these changes will impact flood risk.
Uncertainty in projections of storm track changes leads to uncertain future wave climate predictions. UKCP18 predicts a decrease (~10%) in offshore significant wave height but there is little consensus between climate models, with some predicting a potentially large (10-15%) change in maximum offshore significant wave height.
This study focused on the Isles of Scilly, an archipelago off the south-west tip of England. Flood risk across the islands can be largely attributed to wave overtopping. Tests were performed keeping the mean sea level constant and changing the offshore wave climate.
Results will be presented to show that inshore wave conditions are less sensitive to changes in the offshore wave climate due to depth limiting of the waves (i.e. a 10% increase in offshore wave heights results in a <10% increase in inshore wave heights).
Morphodynamic modelling of a barrier island recharge scheme, South Ford, Benbecula
Within the coastal environment, shoreface processes and associated sediment redistribution is one of the most challenging processes to accurately represent within computational modelling, particularly when the beach profile undergoes significant modification.
We applied modern numerical modelling techniques to assess the performance of a proposed recharge scheme on the exposed barrier island of Gualan in the Outer Hebrides, Scotland. Using a 2D version of XBeach, we replicated observed conditions on the island and within the tidal basin of South Ford.
Using local datasets, joint probability extreme events were derived and used to assess the performance of the nourishment scheme under extreme and ambient conditions. This novel, 2D approach facilitated analysis of the proposed scheme under extreme and ambient conditions, allowing annual recharge volumes to be calculated accurately and residual risk estimated.