Stuck in the mud?

Sand and mud banks form important barriers around our coastline but climate change means that the way in which such sediments are moved around by water currents could change.

Professor Daniel Parsons in the Department of Geography at the University of Hull has just begun work on a large research grant to assess how the change in movement of these fine materials could impact on our estuaries and coastlines.

The project will investigate how the presence of cohesive, 'sticky' muds within sandy sediment influences the erosion, transport and deposition of this mixed sediment in rivers, estuaries and seas.

Professor Parsons explains: "Many people in the UK live within a few miles of estuarine or coastal environments; mud and sand are mainly found here and they are very important for the ecology and economy of the UK. They provide nutrients for many species of birds and fish, but also protect the coastline from the erosive forces of the sea. Because of the importance of these muddy and sandy systems, their natural behaviour and, most importantly, their stability is of increasing concern as sea levels rise with climate change".

He adds: "We have limited scientific information to help us to predict how these natural mudflats and estuarine environments will respond to the changing forces of the tides, wind and waves.

"The main issue we have is a lack of knowledge concerning the dynamics of mixtures of sand and mud. 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. How the 'sticky' mud interacts with the sand and understanding how these mixtures move within river, estuarine and coastal environments is key for improving our predictions."

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, St Andrews. The project is being led by the University of Bangor.

Part of the research programme will involve state-of-the-art surveys of the Dee and Humber Estuaries and an allied experimental programme at the University of Hull's Total Environment Simulator at The Deep.

Provided by University of Hull