Langstone Harbour entrance coastal process study

Minor funds contribution 2018-2020

Alex Hillawi, Eastern Solent Coastal Partnership: £4000

The SCOPAC coastline is intersected by multiple tidal inlets. Coastal processes at these locations are typically complex, often producing morphological changes which can have serious management implications. A good example of this can be observed at the Langstone Harbour entrance (see Figure 1) where complex sediment dynamics result in hotspots of erosion and accretion causing multiple management issues.

Figure 1: Sediment transport pathways at the Langstone Harbour Entrance (SCOPAC STS, 2012)

It would appear from recent regional monitoring programme (www.channelcoast.org) data that the two local sediment sources feeding Eastney spit (the West Winner and Horse and Dean Sands) are no longer present. The reasons behind this are not currently understood and a better understanding is required in order to manage the frontage and the private and commercial properties located on the spit.

The SCOPAC minor fund project being led by the Eastern Solent Coastal Partnership (ESCP), in combination with a Master’s thesis being undertaken by Alex Hillawi at the University of Southampton, will investigate the coastal processes in more detail. In particular, the research will examine the reduction and loss of the West Winner and Horse and Dean Sands and the impact this will have on the long-term management of Eastney Spit in terms of a reduced sediment feed.

The grant will contribute towards the cost of RFID tracer pebble surveys to track material movement around the spit. The resulting data will then be analysed in GIS, alongside existing regional monitoring programme data.

The grant will contribute towards the cost of RFID tracer pebble surveys to track material movement around the spit. The resulting data will then be analysed in GIS, alongside existing regional monitoring programme data.

‘Pebble preparation of 500 native pebbles was completed over the winter 2018/19 with the tracer pebbles deployed along the open beach and spit at Eastney in April 2019. Ongoing surveys are now underway to track the direction and rate of movement of the tracer pebbles over the next year. Findings will support the Eastney Spit Feasibility Study.