Pagham harbour - Intertidal Sediment Dynamics of a long-term realignment site (PHIP)

The intertidal mudflat/saltmarsh environment is a one of the most productive ecosystems and also forms a natural coastal defence as it dampens wave height. Because of coastal squeeze there has been considerable loss of this type of habitat in the UK. One of the ways that is being used to compensate for this loss of habitat, as well as providing a better level of flood protection, is by means of managed realignment. In order to predict how these new re-inundated systems may function in the long-term there is a need to gather data from sites which were breached (accidently) many decades ago.

Since 2000 the University of Brighton have been monitoring the intertidal sediment and hydraulics of Pagham harbour. This site, part of a silted sea strait was reclaimed for agricultural purposes in 1876 and then in 1910 a severe storm resulted in the breaching of the spit and once again the site was opened to the influences of the sea.

A detailed data set is continually being collected and analysed on the erosion, transport, deposition and consolidation cycle (ETDC) of the cohesive sediment, alongside the influencing hydraulic and meteorological factors.

This long-term project linked closely to the work later conducted in Medmerry Nature Reserve and Chichester harbour.

The project aims have been as follows:

> to further the understanding into the sediment dynamics within anthropogenically controlled intertidal environments
> to advance the understanding of how intertidal sediment environments respond to meteorological events.

To date, this project has described the relationship between saline stratification, lunar cycle and the landward movement of fine suspended sediment. The project has identified a relationship between depth and fetch limited waves and SSC levels. The influence of rain in the ETDC cycle has been identified and is currently being quantified.

The ongoing findings from this research have been used by a number of agencies and organisations who are involved in the management of the coastline.

Selected publications
Burgess, H.M., Pope, D.J. and Cundy, A (2008), Measurements of the Effects of Rain on Exposed Mudflats, Proceedings of INTERCOH 2007

Mitchell, S.B., Burgess, H.M., Pope, D.J and A Theodoridou (2008) Field studies of velocity, salinity and suspended solids concentration in a shallow tidal channel near tidal flap gates, Estuarine and Coastal Shelf Science, 78, pp. 385 - 395

Mitchell, S.B., Tinton, E. and Burgess, H.M., (2006), Analysis of flows and water levels near tidal flap gate, Maritime Engineering 159, pp. 107–112

Mitchell, S.B., Burgess, H.M. and Pope, D.J, (2006), Stratification and fine sediment transport mechanisms in a semi-enclosed tidal lagoon (Pagham Harbour, West Sussex), Water and Environment Journal, 20, pp. 248 - 255

Burgess, H.M., Mitchell, S.M. and Pope, D.J. (2004), Forcing factors affecting cohesive sediment fluxes in an estuarine lagoon, Pagham Harbour, UK, Seine Aval symposium “Changes in land uses: consequences on estuaries and coastal zones”, 13-17 September 2004

Burgess, H.M. (2004), Cohesive Sediment Fluxes of Pagham Harbour, Solent Coastal Management Conference, University of Portsmouth, 27-28 April 2004

Mitchell, S.B., Burgess, H.M. and Pope, D.J., (2004), The influence of tides and wind on fine-sediment transport in a semi-enclosed sheltered natural harbour (Pagham Harbour, UK), JHR special issue 41 pp. 141-147

Mitchell, S.B., Burgess, H.M. and Pope, D.J., (2004),Effect on estuarine fine sediment transport of intermittent pump discharge at Pagham Harbour, West Sussex, Water and Environmental Journal, CIWEM, 18(1), pp. 39-43

Mitchell, S.B., Burgess, H.M. and Pope, D.J. (2003), Observations of velocity, salinity and suspended Sediment concentrations in a semi enclosed tidal lagoon (Pagham Harbour, UK), Proceedings of RCEM third IAHR Symposium on River, Coastal and Estuarine Morphodynamics, Barcelona, 2003, pp. 516 - 523

Burgess, H.M., Mitchell, S.M. and Pope, D.J. (2003), The influence of wind induced waves upon the turbidity of an estuarine lagoon, Pagham Harbour, UK, Proceedings of RCEM third IAHR Symposium on River, Coastal and Estuarine Morphodynamics, Barcelona, 2003, pp. 1166 – 1175

Burgess, H.M., Mitchell, S.B. and Pope, D.J. (2002), The influence of tides and wind speed on fine-sediment transport in a semi-enclosed natural harbour (Pagham Harbour, UK), Proceedings of the Fourth International Conference on Environmental Problems in Coastal Regions, Coastal Environment IV, Rhodes, pp. 193 - 202

Burgess, H.M., Mitchell, S.M. and Pope, D.J. (2001), The Movement Of Cohesive Sediment In Semi-Enclosed Harbours, Set for Britain, presentations in December 2001 by Britain’s younger engineers, House Of Commons, London