GEOGRAPHY COURSEWORK
BY
A. Student
Should Dunwich be defended from coastal erosion?
Introduction
Aims of the project
The purpose of this coursework is to collect enough information so we can answer the question “Should Dunwich be defended from coastal erosion?”
We will also be able to learn about coastal erosion and other coastal processes.
About Dunwich
Dunwich is a small village on the east coast of Suffolk. It has a 1.6 kilometre beach and attracts tourists in the summer. It is a quiet, rural area with Southwold to the north and Sizewell power station to the south. It is a sparsely populated area. Dunwich Heath is one of Suffolk's most important conservation areas. It is an Area of Outstanding Natural Beauty and was probably formed in the Neolithic era, when early farming cut back the wildwood, thus permitting heather, gorse and acid grass to become established. The National Trust is following 5000 years of farming history in managing the land to maintain the ancient landscape and its wildlife.
Issues and values
For the past 400 years the sandy crumbling cliffs backing the beach have steadily been eroding. There have been a number of options suggested for their defence against further erosion. However, if Dunwich was defended from coastal erosion it would affect other places in the surrounding area along the same part of the coast and we need to decide if it is worthwhile. We need to decide which measures would be cost-effective and if any propose coastal defences would be harmful to the environment. But whatever the answer there will be some people against the idea and some for it. I will need to develop my own opinions and values.
Key questions
Where is Dunwich?
It is a small town in the Suffolk Coastal district of the county of Suffolk, England, on the North Sea coast. It is 26 miles north east of Ipswich and 4 miles south of Southwold.
What do we know about its history?
The first development on the site was probably a Romano-British community, and in Anglo-Saxon days it became the most important commercial centre in East Anglia. Early in the 7th century, when Sigebert became king of East Anglia, Dunwich was chosen as his capital, and a bishopric was founded before 650. The community received a charter from King John (reigned 1199-1216).
Dunwich became a wealthy port, but severe coastal erosion caused its decline. In 1347 more than 400 houses were washed away in a storm, and similar disasters occurred in 1570.
Until 1832, Dunwich returned two members to Parliament in spite of its small population. The corporation was abolished in 1886. The population in 1981 was 129.
Dunwich also figures in literary history. Edward Fitzgerald took the writer Thomas Carlyle to visit Dunwich in 1855; Fitzgerald also came to Dunwich whilst he was translating the verses of the Omar Khayyám in 1859. Jerome K. Jerome, author of ‘Three men in a boat’, spent annual holidays here around 1900 at lodgings provided by a Mrs Scarlet who also kept a shop.
Swinburne's 'By the North Sea' from Studies in Song (1880) was inspired by his visit. Edward Thomas finished the first draft of his biography of Richard Jefferies in 1907 in a coastguard cottage at Minsmere, high up on 'a heaving moor of heather and close gorse', half a mile away from where the ruined church had half fallen over the eroded cliff.
How has Dunwich been affected by erosion over the years?
Over the past 400 years approximately one metre of land per year on average has been eroded
What coastal processes operate and what coastal features are there at Dunwich?
This is covered in the next chapter where a beach profile and a cliff profile are discussed
What coastal defences are there?
In the 15th Century, the inhabitants of the village devised a way of defending the coast. Each autumn they would tie up piles of wood and shingle and place them at the base of the cliffs. This was a very effective method of defence for over 200 years. There are not many coastal defences at Dunwich, just some sand dunes and clay banks. These are not very good defences as the sand dunes are worn away by people walking on them and the only thing holding them together is Marram grass.
What options exist for defence against coastal erosion?
The following options exist:
Rock revetment – approximate cost $4500 per metre of coast, but variable.
Offshore rock barrier (breakwater) – approximate cost £6500 per metre.
Wave return wall – cost £6000 per metre of coast.
Groynes – Approximate cost: £5000 per groyne
Data Collection
History of erosion
In the 5th Century Dunwich was a port on the bay shoreline, approximately 2 KM from the open sea.
From 1587 – 1702 107m of land was removed. Between 1702 and 1754 a further 160m was eroded and up to 1973 121m were removed. In 386 years, 388m of coastline have been lost (approximately 1m per year), although this has not been true in all areas.
Most rapid erosion rates over 5 years are:
South of Millgate Street 4 feet
South of Greyfriars14.5 feet
All Saints graveyard11.5 feet
Cliff Profile
This shows the cliff profile that I did on the visit to Dunwich, so that we could see what the land is made of and whether it is prone to erosion.
Brown soil / 15cmOrange/grey soil / 15cm
Light grey soil / 30cm
Humus – decomposed plant matter
Sand & clay / 1 – 1.5m
Pebble – old river bed
Orange sand with clay
Dark orange/brown iron pan
Small grain sand
Data Analysis
Timeline
Pebble size
Pebble size / % in sample50 mm / 5
40 mm / 5
38 mm / 10
30 mm / 15
25 mm / 25
20 mm / 40
Graph to show beach profile
Cliff composition
Brown soil
/ 15cmOrange/grey soil / 15cm
Light grey soil / 30cm
Humus – decomposed plant matter
Sand & clay / 1 – 1.5m
Pebble – old river bed
Orange sand with clay 15cm
Iron pan
Small grain sand
To bottom of cliff
Field sketch
Coastal defences
Rock revetment
Offshore rock barrier
Conclusion
What is the best decision for coastal management at Dunwich?
After gathering all this information about Dunwich I have come to the conclusion that it is too late for Dunwich to be defended from coastal erosion. This is because there is nothing left to defend except the houses, so there is no point in spending money on defending Dunwich.
If any money was to be spent then only soft defences should be used.
Defending Dunwich from coastal erosion could also have serious repercussions along the coast and it should not be forgotten that the Sizewell A and B Power Station are a little way along the coast