Coastal erosion problems in Walton on the Naze

Data collection.

1. This section is going to include my findings from my field trip to Walton on the Naze, this will include; a map, groyne measurements, field sketches of managed and unmanaged coastline, photos, questionnaires of peoples attitudes, cross section along transects of defended and undefended coastlines and secondary sources of information.
2. On the map (figure 1) I have outlined the nature reserves, the managed and unmanaged coastline and the coastal defence features.  I collected the information on the map by going to Walton on the Naze, we walked around the managed and unmanaged coastline, and I was able to put the main features on the map.  The map is important to my study because I will need it to see how close the houses are to the recessive coastline, I will also need it to see how the receding coastline will affect the land use.  I had problems collecting the data because I had a small map and a lot of information, I could have overcome this problem by getting a bigger map.  I could have also got similar information by going on the Internet, or looking on a land use map of Walton on the Naze.
3. Groyne measurements: longshore drift is the movement of material along a beach.  When a wave breaks obliquely, pebbles are carried up the beach in the direction of the wave (swash).  The wave draws back at right angles to the beach (backwash), carrying some pebbles with it. In this way material is moved in a zigzag fashion along a beach.  Longshore drift is responsible for the formation of spits.  Attempts are often made to halt longshore drift by erecting barriers, or groynes at right angles to the shore.  We were trying to find out how much longshore drift was taking place so we collected the data by measuring each side of the groyne, the north side and the south side; we did this at the top, middle and bottom of each groyne. On one side of the groyne the sand is higher, this is because of longshore drift.  The problems that we had were that the tide was turning and coming in so we had to take the measurements where we weren’t going to get wet, we could have solved this problem by waiting until the tide had gone out so that it was at low tide level. Another method I could have used was to put an orange in the water and see how long it would take to travel a distance of 5 metres.
4.  The Information shown on the field sketches are of the herring-bone drainage system, and the different layers of the cliff. The photo also shows this (page 6).  The different materials in the cliff face are sand, London clay and then there would be chalk deep underneath ground level.  I carried out these sketches by looking up at the cliff top and then looking at the unmanaged coastline. We took the photographs in the same way. I didn’t really have a problem doing the sketches.
5. Sampling beach materials:  I need to sample beach materials because different size stones will relate to the amount of erosion going on.  I collected the data by taking 3 handfuls of sand and estimating how much of each sized material was in each handful. The only problem which I had was that the tide was covering the very bottom sand, so I had to take a handful of sand from the lowest point possible on the beach. I could overcome this problem by collecting the data at low tide,
6. Cross sections: we collected a cross section of the managed beach.  On the cross section (page 9) I labelled where everything was and I put the distance in metres and the sea wall. The problems, which we had, were that the vegetation was getting in the way. I could have overcome this problem by moving to a different location along the coastline.  
7.  Questionnaire; I did the questionnaire because I need to know what sort of information people know about the Naze, such as did they know anyone, or live near to the unmanaged coastline at the Naze? I collected the data by walking around Walton on the Naze and collecting data from people.  The problem that I had was that people don’t know where on the map they lived; I overcame this problem by looking for features on the map near to where the people live.
8. The sources of secondary information that I have, I got from the Internet or from a textbook, I looked at website especially dedicated to the erosion at the unmanaged coastline.  The problem that I had was that there were not many websites on the Naze; they were just mainly on Walton as a whole. I overcome this problem by going to the search engine goggle.

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                        Data Analysis.

 

Sketch map: My sketch map (fig 1) shows me that the coast is less eroded by the tower breakwater, as there is a sea wall, groynes and riprap there so the sea cannot erode away the sea wall. The coast is more eroded beyond the tower breakwater, as the beach is unmanaged.  Where the coast is eroding.  This is in grid reference 2623.

 There is a nature reserve and many species of plants and animals live there. The pillboxes that you see on the wave cut platform were at the top of the cliff in 1945 when they were built and now they are 60 metres east of the bottom of the cliff.  If you look south of the tower breakwater there is no erosion.  You can see the groynes, sea wall and cliff regarding here.  All this work has been done as people live here, where as there are no houses and no people living where the cliff is unmanaged  

Longshore drift:  the results of my longshore drift survey show that there was a build up of sand on the south side of the groyne.  Groynes prevent coastal erosion (longshore drift) as it holds the sand and therefore stops the waves from hitting the cliff.  Where there are no groynes the sea hits the exposed cliff and it undercuts it through hydraulic action and then the cliff crumbles away.  The more longshore drift the more erosion of the cliff.  Along the breakwater the highest build up of sand is on the nearest point of the breakwater to the cliff or sea wall on the south side.  It also shows this on my graph (figure11& 12) Longshore drift is a problem as it undercuts the cliff and it erodes the cliff back by about 2 meters a year.  Groynes prevent costal erosion, as the long shore drift cannot hit the cliff, as the groynes take out the power in the waves.  The groynes have been built at an angle so the long shore drift had moved the sand and the sand have been gently pushed up between the breakwaters.  So I think that they must put groynes at Walton on the Naze, but they must put them in the correct position / angle, they need careful scientific measures to ensure that they calculate the correct angle.

 

Beach material:  From the results of my beach material survey I have found that in the managed beach it is made up of on average 30% boulders, 40% pebbles and 25% shingle.  ( figure3)There are bigger stones here so they would absorb the waves energy- so there would be less erosion. In the unmanaged beach there is on average 70% bedrock, 20% sand and 10% pebbles. Small particles such as sand don’t absorb the waves energy therefore waves keep their power and erode a lot more than it would if their were large stones. If stones or rip rap were put on the unprotected coast, coastal erosion would decrease.

Cross sections and sketches and photos: my cross sections (figure 9) show that the sea wall on the managed beach goes up at an angle this is because cliff regarding through bulldozing the cliff.  My sketches show me that there is a herringbone drainage system running down through the cliff preventing the cliff from getting water logged. Another one of my sketches (figure 7 )show where the Naze is situated and the other sketch shows what’s behind the regarded cliff.   The bedrock influences the coastal erosion as it the foundations of the cliff.  The southern end is managed differently to the north end, as there are houses with people living in them at one end and mainly farmland at the other end.

Erosion figures (erosion rates between 1875 and 1996):

The rate of the erosion is proportional as it nearly doubles each year in comparison to the previous year.  On the southern end of the Naze at the year 1980 the erosion rates were 1.42 metres and in 1986 they were 2.84 metres. In 1875 there was a difference of 0.3 metres between the southern end and the northern end, now there is a difference of 0.8 metres this has gone up 50 metres. The dredging in Felixstowe might affect the rates of reaction, as there would have not been as much sand to protect the exposed cliff.  My spearman’s rank diagram shows that there is a positive correlation between each of the north and south side.

Solutions:  in my opinion there should be a sea wall protecting the cliff from erosion this is because there is a nature reserve with lots of rare plants and some animals.  I think that a sea wall should be built but there comes a problem with this as further down the coast in places such as frinton and Clacton there would be no sand as all this is trapped in Walton on the Naze.  The hotel owners in frinton would be against this, as the beach would no longer attract tourists, also the souvenir shop owners would be against this.  People who live close to  the unmanaged coastline would be for this as there houses would be at risk from falling with the receding coastline.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                Conclusion

 

1. What is the evidence of erosion? Yes I think that there is evidence of erosion. The evidence of erosion is that on the map there are pill boxes in the sea which would have once been on the cliff top, and their is a line north of the tower breakwater which says where the cliff top used to be.  Many people said that with the questionnaire results they knew that erosion was taking place, 8 out of 10 people said that they knew about the erosion at the Naze. I also have photos of the cliff crumbling away through erosion.  
2. Which processes are responsible? Long shore drift, erosion and weathering are responsible for this as the waves from long shore drift hit the unprotected coastline, on the managed section of coastline there are groynes which would stake the power out of the waves from hitting the sea wall. Hydraulic action hits the bottom of the cliff undercutting it and making it weak. Weathering – biological, chemical and physical also play a part in the eroded cliff, as the water from the rain soaks into the cliff.
3. What are people’s opinions? The questionnaire states that people know what’s going on at the Naze and that something should be done about it. There is also a save the Naze campaign.
4. What options are there? In the geography books it says that; you could use riprap or cliff regarding.  Most people think the something should be done about the Naze.
5. What do I think should be done?  I think that there should be some coastal defences put in place as the cliff is being eroded at some distance per year.  I think that a re-curved sea wall should be put in place and that some groynes should also be put in lace.  This has happens at the managed beach as well as Clacton and frinton.  If defences are not put in place peoples houses and businesses are going to be put in danger.  

                                                                                                                

Opinions

1. A hotel in frinton would be against coastal erosion, as the groynes would prevent the sand from flowing down the coast to frinton, some coastal residents would also have this opinion.
2. The tourists that are old will also be against coastal defences as they are ugly and people that are quite young will be for coastal erosion so that the coastline will be preserved for many years of visits.
3. The engineering company will be for coastal defences as they would get work and get paid vast amounts of money.
4. The birdwatchers would be against coastal defences, as it would affect the sand martins as they nest in the exposed cliff.  If the coastal defences were put into place, there would be nowhere for the birds to live.
5. The people living at the Naze would be for coastal defences as their houses are at threat from the sea.
6. Other people want government money, why should people pay for the coastal defences out of their taxes?  When the people who live close to the Naze chose to live their, knowing that there was no coastal defences.

                                                                                                                                                                                                                                                                                                                                                                                                        

Evaluation.

1. Limitations: 

The beach material data could have been more accurate as we had to estimate it, a solution to this is to weigh each material and take a percentage from that. We could have also taken more samples and at different times of the year and made a comparison between the two.  In my opinion the long shore drift results were fine, as we took a measurement from the top middle and bottom of the groyne and on each of the north and south sides. I thought that the cross section results could have been more accurate as the wind could have blown the angle measurer. A solution to this is to use an electronic angle measurer.  We also had to estimate the angle on the top of the unmanaged cliff because it was too dangerous and we were not able to climb the cliff. A solution to not estimating this is to climb the cliff( with safety protection) and to use an electronic angle measurer.  For the questionnaire I asked only 10 people in the same day if I were to ask this again I would ask at least 100 people and I would ask people at different times of the year for example in the summer holidays and in the winter.        

2. Possible improvements: 

To improve my results I would use more sophisticated equipment such as an electronic angle measurer for measuring the angles of the cliff.  I would also hire people to do the work for me so I would be able to get more accurate results, in a shorter length of time.  I would also do a door-to-door survey, so I could get more questionnaire results and they would be of what the people next to the sea and people a bit further away from the sea and make a comparison on the two results.  I would also take more measurements at different times of the year that were accurate and I could make a better comparison between the results.  I would also take more long shore drift measurements. I could have also done my write up a bit quicker.  We could have also returned to the Naze and taken more measurements.