To the North if Swanage lays Clayton which is impermeable and has a great surface run off. There is also little interception, as most of the vegetation lies outside of the river basin.
Swanage town is now a built up area so there is an even greater risk of flooding because of the impermeable ground. The grounds surrounding Swanage are Weldon clay and Purbeck beds, increasing the surface runoff even more greatly. There is also little vegetation decreasing the amount of interception making Swanage prone to floods.
Question 3
The purpose of the experiment was to analyse the changes between the natural and man made river in Swanage, and effectively prove which river is more efficient, through use of comparison.
Theoretically, the man made river should be more efficient, it is wider, deeper and the banks are smooth and straight, allowing freer flow of water. A greater capacity of water is able to be transported more quickly, hence fourth making the man made more reliable and reducing the risk of flooding.
In order to establish differences between the two rivers the same test were conducted at different parts of the river, man made and natural. The first of the tests were at the natural river, monitoring actual flow. To find the wetted perimeter a tape measure was draw from the left bank were the water met the land, and then to the right bank where the measurement was taken. The tape measure was pushed to the floor of the river in order to get the perimeter
Secondly the width was taken from the actual flow of water, using the tape measure starting at the left bank finishing at the right bank. Next the depth of the water was taken at regular 20cm intervals using a meter ruler for the depth and the tape measure to mark the intervals. Then the velocity was taken over a 5 meter range, firstly using dog biscuits and secondly a -----------------. A five meter distance was measured out with the tape measure, then using a stop watch, a dog biscuit was placed at the start of the 5 meters, and the time it took for the dog biscuit to get the end of the five meters was the velocity. This was repeated three times.
Then a -----------was used and the velocity results were taken three time.
When measuring the channels full flow, the same methods for actual flow were adopted. When we measured the depth however the measurements were taken at one meter intervals rather than 20cm intervals. These same operations were repeated at the man made river.
As predicted the graphs show that the man made river has a greater depth and width in comparison the natural river. However surprisingly the man made river seems a lot less smooth, with sudden depth changes. This however shouldn’t affect the effectiveness of the water flow of the river.
Results
Natural channel (actual flow)
Width of water (cm): 1m10cm
Average depth (cm):
Velocity (x3) (m/sec)
Dog biscuits:
Test 1: 35sec
Test 2: 35.55sec
Test 3: 39 sec
Pole thingy:
Test 1: 0.13
Test 2: 0.02
Test 3: 0.01
Average Velocity (m/sec): 7.3
CSA av. 4m (Squared)
Wetted perimeter
(Land in contact with water): 2.50m
Discharge
(CSA x av. Velocity): 0.53m (cubed)
Efficiency
(CSA/wetter perimeter): 1:6
Natural channel (bank flow)
Width of water (cm)
Bank to bank:
Average depth (cm):
Wetted perimeter
(Land in contact with water if bankfull) (m): 4.10
Discharge
(CSA x av. Velocity):
Efficiency
(CSA/wetter perimeter):
Manmade channel (actual flow)
Width of water (cm): 3.60
Average depth:
Velocity (x3) (m/sec)
Dog biscuits:
Test 1: 27.61sec
Test 2: 35sec
Test 3: 29sec
Pole thingy:
Test 1: 0.04
Test 2: 0.05
Test 3: 0.01
Average velocity (m/sec): 0.16 sec
CSA x av.13m (squared)
Wetted perimeter:
(Land in contact with water): 4.10m
Discharge
(CSA x av. Velocity): 2.08 m (cubed)
Efficiency
(CSA/wetted perimeter): 3:2
Man made (bank flow)
Width of water
(Bank to bank) (cm):
Average depth (cm):
Wetted Perimeter
(Land in contact with water if bank full) (cm):
Discharge
CSA x av. Velocity)
Efficiency
(CSA/wetter perimeter)
Although the results gathered were somewhat logical and accurate, the fairness in the testing could have been made much more reliable. For example more tests could have been conducted; technology rather than human judgement could have been used. The heavy rain on the day of the experiments also caused a problem and differed fairness. More tests taken at different times of the year would also enhance the reliability of the result. The guide which we had was also hard to understand and was not confident when conducting the investigations and did not explain simple things like what was the natural and man made channels, so people gathered different interpretations of what she was saying.
Question 4
Beach
The purpose of this experiment is to see what effect Banjo pier, has on Swanage Bay in relation to the build up of long shore drift. The process in which the prevailing wind pushes material up the beach at an angel, and in which the backwash carries the material back out to sea in a straight line. This means that material gets carried all of the way up the beach and can end up as a spit, unless there is something in the way. Groynes are therefore used to control the transportation of material.
I expected that the South of Banjo pier will have a greater accumulation of sand than the North because of the North East prevailing wind, the East facing beach and Banjo pier, which I expect to act like a large groyne. Most erosion takes place here where the most common wind is South Easterly so waves erode the shore; therefore I expect that long shore drift will move material from the South to the North of the beach.
We went to Banjo Pier and took measurements from both the North and south side of the pier. This was so we could compare the North and South of the beach. Starting with the North side of the pier, we measures the width of the beach, by sticking ranging poles where the beach emerges and where there was an inclination in the beach. We then measured the difference between the two ranging poles using a tape measure and then using clinometers took the angel measurement of the inclination of the beach, recording each result. We then repeated this at every noticeable inclination of the beach until we reached the beach wall. This was then repeated on the South side of the beach.
The results show that the beach is larger on the South side of the beach. On the North side of the beach there was only 9.50m of beach we could measure, whereas on the south side there was nearly 24m beach we were able to measure. On the South side of the pier the inclination angles were much greater, than the North. However on the North side of the beach the inclinations were more often. This agrees with my prediction that Banjo pier does in fact act as a big groyne.
In order to improve the results I would repeat the experiment at different times of the year. A good time to do this would be during the winter, when the beach would have probably have been affected by winter storms. I would also repeat the experiment at different times of the day, because the tide has a big impact on the movement of material on the beach. I would generally repeat the experiment more to get an average. I would use different staring points to compare answers and find the average and I would test a larger area of the beach. The wind during the experiment impaired the results, because of the clinometers angel measure was not accurate enough and the wind provoked its movement. Generally the human judgement in the tests means that the results are not completely accurate. I would use better technology as a means to get more precise results.
Environment
The purpose of investigating the environment was to see if the Swanage Flood alleviation scheme had had a positive or negative impact on the environment.
I expected that there would be negative aspects of the scheme such as the views of the flood sites and disruption of life from the input of the culvert and reservoirs. However I expected that certain aspects such as little litter and vandalism would be positive and there would be little or none of it.
The method was to visit different site of the Swanage Flood Alleviation Scheme and fill in the same quality surveys for various aspects of the environment and then after compare them. We gave each aspect a positive or negative score.
Through doing the survey I discovered that my hypothesis was in fact wrong and that at each place we visited the site survey came out different. For example I thought that there would be little litter when in fact there was at least some litter at each site. Vandalism varied at each site, but there was surprisingly a lot. I was also shocked to find that the visual impact of each site was generally natural and there was a great amount of care taken in covering thing like the storage areas and things like the culvert.
I would improve the results by having a stricter questionnaire as peoples opinions differ so what I think is litter other people may not consider as litter. I would need to form a tally chart in order to be able to get others opinions and generate a wider knowledge of what people consider things like ‘litter’ are. I would then go out and repeat the survey.
I would look at the environment at different times, for example, as it is a tourist area, I would look at the site during the summer and I expect there would be more litter. I would ask more survey questions to accrete a wider knowledge of each site, and I would go to more sites to generate a greater understanding of the true environment of Swanage. Finally I would go during a flood to get an understanding for what the sites look like during a flood and if the sites actually hide and prevent the damage which is done to the environment during a flood.
People
The purpose of this task was to find out what the people of Swanage thought about the Swanage Flood Alleviation Scheme, and to see what affect, if any, it had had on the locals.
I expected that the Swanage Flood Alleviation scheme had had a positive effect on the people of Swanage because there had been no floods since the scheme had been set up. I order see what effects it had had in small groups we came up with a questionnaire and asked a total of 10 people around Swanage town centre there opinions on the scheme. The questions and answers are as follows:
Q1. Do you live in the Swanage area?
6 yes
4 no
Q2. Have you been effected by the floods in the past.
4 yes
6 no
Q3. What is your opinion on the SFAS?
6 good
4 bad
Q4. Do you feel safer from the risk of flooding?
7 yes
3 no
The Swanage Flood Alleviation seems to have affected the people in a positive way. People generally fell safer about where they lived. Many people did not know about the scheme, which is a good thing as this means that there is little evidence of things such as reservoirs and it means that the scheme is indeed working.
Many people could not answer our questions because they were busy or too old to realise we were talking to them. Also many people had already been asked on the questionnaire by other people and so did not answer our questions. I would improve by send letters of the questionnaire out to people so that they could be prepared to answer my questions.
We got a wide variety of people to answer our questions and people had efficient and opinionated answers to our questions. I would improve by asking more people more questions and by asking people at different times of the week and year. For example on a weekend or at summer it is more likely that there are more tourists so there would be less chance of getting a local person to answer the questions. During the week it is likely there would be more local people or people with a wider knowledge of the area because it is work time and the employment in Swanage is mainly through shops so working with the public.
Conclusion
For my GSCE geography coursework I was asked to investigate to what extent had the Swanage Flood Alleviation Scheme had on the environment and people of Swanage. I investigated how Swanage had been affected by floods in the past, what caused the floods, what has been done to control the floods and what have the effects of the Swanage Flood Alleviation scheme been on the environment, the beach and the people.
The Swanage flood alleviation areas are very natural and often open spaced, with no obvious evidence of the artificial applications such as reservoirs. The river provides an efficient water relief and there is little residential residing here which mean the effect on the of Swanage people is minor. Therefore this has had a positive impact on the people and environment of Swanage. Most of the control methods of the scheme are well hidden using a mixture of grass-creat and artificial rivers which look natural to the environment and there is yet to be a flood since it has been erected in the ----. Where there are little signs of there being flood alleviation methods, it is usually in low populated areas, such as the flood storage areas shown in the environmental survey.
The Swanage flood alleviation does not provide 100 percent safety, but is controlling the flooding up to date. There is evidence that the sea wall of Swanage has been severely damaged and will eventually crumbling in big blocks in which case the money spent of the Flood Alleviation would have been a waste. Other negative points about the sites are that they sometimes contain litter and have bad smells surrounding them because of back swash from the sea. Most locals feel safer but not entirely safe shown in the questionnaire asked.
The Swanage flood alleviation scheme seems very successful although there has been no major storm since its construction so it has yet to be put to the test. However a lot of the Swanage people seem to feel safer than they did before, which suggest it was millions well spent. The scheme is working but the danger of the sea wall collapsing makes me question what other type of evaluation reports people took on the area before they put the Flood scheme into practise. I would like to see how the scheme would work during a major flood and if it could handle it. Generally the effects of the scheme on the public and environment have been good. There are obviously slight faults in such things as landscape and one farm owner had to sell his land in order for the scheme to take place, but generally there are no longer floods in Swanage, which would cause more damage to the environment than the new physical aspects. The people therefore are now safer and more comfortable as demonstrated in my pie chart.
The economy no longer feels threatened on the basis that they might go out of business because no body can reach there shops during a flood, services are no longer on red alert during storms and are no longer stretched to perform for the public. Finally the environment is no longer damaged by becoming water logged and deprived and the areas of flood relief are so well hidden hat people do not even realise they are there. So yes if feel the scheme was a success.