By MSc COMEM student Thomas Cowan:
A new school year brings a lot of excitement for the CoMEM students coming to Southampton for the fall semester. New courses and a new culture have everyone anxious for the start of the semester. This autumn, we also meet with new students taking the ECE masters program based at the University of Southampton and our first interaction with them comes though a joint field-trip during induction week. The field trip was led by Professor Nicholls with the help of Dr Kassem.
Our first stop is Portsdown Hill, which has great view over much of the Eastern Solent. The Solent is part an ancient river valley running between what is now France and the UK. As sea levels rose since the last ice age, the valley was flooded, and material from the old land bridge has been push towards the UK to create the Solent as it exists today. Professor Nicholls uses the vantage point to highlight more recent history of the Portsmouth area. Poldered salt marshes, collages of human intervention techniques, and heavy development has had an impressive impact on the region with many nuances. This long history of human interruption of natural processes has led to a wide range of issues in the region today and we are assured that we will be introduced to over the course of this semester. To demonstrate some of the recent work on the Solent, our next stop is down on Hayling Island by the coast.
In particular, the shingle beach at Hayling is of interest since it’s been the site of a nourishment in the late 80’s. The retreating coastline in the region is a result of a declining sediment supply that was likely caused by human interventions up-drift of the area. The intention of the nourishment is to replace some of the material that has been lost from the area over time. We are shown some of the more recent work and the groyne field that helps to retard the movement of the shingle in the region.
Professor Nicholls highlights some of the unique properties of shingle that we can expect to encounter in one of our optional courses this semester. Apparently, some researchers are able to keep track of the movement and properties of the shingle beach by the sound it makes during large storms. The sound can even be heard kilometres in-land. Unfortunately, as is true in many coastal engineering problems, no solution is perfect and each year monitoring work at Hayling is undertaken and regular maintenance programs bring shingle accumulating by a breakwater at the tail of the coastal cell back to the beginning of the system. Professor Nicholls explains that this solution is an expression of one of three high-level policy options that can be applied across the UK. in the face of ongoing erosion and sea level rise, the government may choose to “hold the line”, “let nature take its course”, or “manage coastal realignment” for a particular area.
The location of our next site visit at Selsy demonstrates this division more clearly. as we walk by a massive trailer park with a horror-movie-esque children’s theme park, an old roller cranks an almost-empty carriage around a rust covered track in the scattered sun. Professor Nicholls explains that this site flooded back in 2008. Since that time, it appears that the owners of the area haven’t been idle. Two large, offshore rock fishtail breakwaters appear recently constructed and have developed large tombolo formations (an area where the natural shoreline has extended seaward over time until it connects to a formation that was originally offshore). There’s also a lot of distinct shingle which Professor Nicholls explains is likely the result of a recent nourishment. At the end of the beach, by an armoured end-section, we look out into the Medmery Managed Realignment Area. This area represents a location where the government has actively undertaken measures to retreat from the coastline.
By retreating like this, the UK hopes that newer sea-defenses landward of the originals will be easier to maintain, and that the reclaimed area is useful as a natural reserve. There is more complexity to the design of these areas than is initially apparent, which Professor Nicholls describes as a significant area of ongoing research. After a long day of beach walks and impromptu lectures in the almost mythical UK sunshine, we finally return with our new classmates to Highfield Campus with a punctuality that I usually retain only for atomic watches. Our next blog post will be on the lecture by Dr Eli Lazarus on October 10th.