Researchers looking at 'goo' to predict impact of coastal storm surges

Predictions on the threat of coastal flooding are leaving out a vital ingredient, claims a University of Hull scientist.

A team led by Professor Dan Parsons in the Department of Geography, Environment and Earth Sciences is recreating realistic seabed conditions in the Total Environment Simulator at The Deep, Hull, to investigate the interaction of sand, mud and biological ‘goo’. It is hoped that the findings will contribute to more precise predictions being made on coastal flooding globally.

The project is the first of its kind to introduce goo (or microscopic biological matter) into the equation as it seeks to better understand the impact of climate change on our coasts and estuaries, and help predictions of flooding from storm surges such as the catastrophic North Sea Flood that claimed the lives of 1,836 people 60 years ago.

When water flows over the seabed, it shapes the sediment into wavy features, such as sand banks, mud banks and ripples, which form important barriers around coastlines.

Globally, present coastal evolution and flood prediction models are based on seabeds that are made purely of sand. But, says Prof Parsons, when mud and goo are introduced, the predictions change completely, rendering today’s calculations far too generalistic.

“Bearing in mind that most coastal seabeds are a mix of more than one type of sediment, it is very important for us to find a more precise method of prediction, especially as sea levels are rising,” he said. “How these mixtures, that include fine materials, are moved by water currents is key to this understanding.”

The scientists are adding mixtures of sand, mud and xanthan gum (the latter to replicate the goo) to a large cement mixer before pouring it into the simulator and recreating a variety of water flows over the mixtures. This is revealing how the seabed is shaped with varying levels of the three components and in varying water conditions.

Dr Rob Schindler, who is part of the team, added: “Our interim results will show how risky it is to base coastal predictions on sand alone. In the future, we hope that coastal areas around the world will be able to use knowledge of their local environment to understand how storm surges could affect them.”

Prof Parsons added that there was almost a complete lack of scientific knowledge concerning seabeds consisting of mixtures of sands and muds. “This knowledge is vital to helping us understand how natural mudflats and beaches will respond to the changing forces of the tides, wind and waves that will result from climate change and sea-level rise,” he said.

The three-year project, funded by the Natural Environment Research Council (NERC) and named COHBED (Sedimentary Bedform Prediction: Incorporating Physical and Biological Cohesion), is a large collaborative effort involving six UK research institutions that includes the University of Hull, the National Oceanography Centre in Liverpool, and the Universities of Leeds, Plymouth, and St Andrews. The overall project is being led by the University of Bangor.

This is one in a series of science stories this spring as the University of Hull celebrates all things scientific during a special ‘science takeover’. The highlight of this will include celebrations to mark the 40th anniversary of the world changing research into the development of modern-day Liquid-Crystal Displays (LCDs), led by Sir George Gray at the University of Hull in 1973.

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Notes to editors

Sandy sediments are known to be ‘non-cohesive’, because the sand particles do not stick together, whereas muds are made up of smaller particles that do stick together and so are called ‘cohesive’ sediments. This difference is one of the study targets of the COHBED project.

Mud and sand are found in places where the energy of waves, tides and river flows is low and these water-borne sediments can be deposited on the sea floor. Muddy and sandy habitats are very important for the ecology and economy of the UK. They provide food for many species of birds and fish, but also protect the coastline from the erosive forces of the sea. They also act as a filter, where pollutants from the rivers are captured and eventually degraded. Because of the importance of these systems, their natural behaviour and stability is of increasing concern as sea levels rise with climate change.

Information allowing us to predict the size and movement of bedforms is essential for many scientific disciplines, such as environmental management, hydraulic engineering, seabed habitat biology, computer modelling of particle transport and sedimentary geology.

About the University of Hull

The University of Hull is an institution with a long heritage of academic excellence and is rich in tradition. Established in 1927 as England’s fourteenth university, it received a Royal Charter in 1954. The University has campuses in Hull and Scarborough.

The University of Hull features some of the most inspirational figures of modern times, and has an illustrious history which includes pioneering developments in science and engineering, health, business, humanities and social sciences as well as performing arts. The University today is a vibrant and future-oriented institution, recognised for excellence in learning and teaching as well as a commitment to research, enterprise and engagement. The University is known for its friendliness and high student satisfaction as well as the employability of its graduates.

The University regularly features in the top bracket of national teaching quality league tables and has consistently performed impressively in the National Student Survey, reflecting the high premium the University places on the quality of student experience. Staff and students frequently win prestigious national and international awards and accolades. Hull is currently placed among the top 500 in the QS World University Rankings.

Research and enterprise are core academic activities of the University. Amongst its most well known achievements are the discovery of liquid-crystal displays and the bone density scanner which revolutionised the detection of osteoporosis, both of which were featured in Eureka UK's list of ‘100 discoveries and developments in UK universities that have changed the world’. The most recent Research Assessment Exercise revealed that 80% of the University’s submitted research is of international standard in terms of originality, significance and rigour.

For more information visit: www.hull.ac.uk

For further information, please contact Catherine Ackroyd at Mapa PR on 01482 589900, 07739 139056, catherine@mapa.org.uk

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