A greater understanding the controls on, and processes of sediment scour is important for dealing with coastal erosion, management of ports and harbours and predicting environmental response to climatic change. Although the dynamics of sand and mud have been intensively studied, comparatively little is known about the dynamics of sediment mixtures (sand, mud, water and biotic components). Whilst the effects of biotic components upon sediment properties and processes are widely recognised, the mechanisms and magnitude of different effects remain poorly quantified. This studentship will address these knowledge gaps by combining laboratory experimentation with field observation, and would suit a student with good practical skills and strong interests in tidal environments.

The erosion of beds composed of different sediment mixtures will be studied in flumes and in situ, comparing, for example, laminated sand and clay with mixed sand and clay. As the project progresses, more complex mixtures will be investigated, including biotic components such as: organic matter and extracellular polymeric substances (EPS) from organisms such as diatoms and cyanobacteria. The student may, for example, investigate the effects of biotic filaments such as roots and microbial strands in isolation from other variables (such as grain sorting). Supplementary data will be provided by the use of ENVs Cohesive Strength Meter and EROMES erosion devices. The research will primarily consider erosion under unidirectional flows, but the development of the new FloWave device for simulating combined wave/flow action will allow the effects of combined unidirectional and oscillatory flows to be investigated.

The student will join a growing group of sedimentary researchers in UEA and there will be opportunities for collaborative work with other UK research groups and possibly also overseas groups. The student will take part in the formal skills training offered to all PhD students in Environmental Sciences and in addition will be trained in experimental sedimentology and field observation as appropriate.

Applicants should have a sound mathematical ability and some experience of tidal environments and laboratory experimentation.

Black, K.S., Tolhurst, T.J., Hagerthey, S.E., and Paterson, D.M., (2002) Working with Natural Cohesive Sediments. Journal of Hydraulic Engineering, January, Vol. 128 (1), 2-8.

Paphitis, D., Velegrakis, A. F., Collins, M. B., and Muirhead, A. (2001). "Laboratory investigations into the threshold of movement of natural sand-sized sediments under unidirectional, oscillatory and combined flows." Sedimentology, 48(3), 645-659.