Diagram 1a
For this experiment no diagram was necessary as we were just finding out what type of stone the rocks were.
Logic
This method was considerably more efficient and simple than any of the others due to its low equipment cost and required workforce. It also provides a lot of quality information that can be used to further our knowledge.
By picking out stones from all over the beach it ensured that we would obtain varying and fair results.
Adversities
Occasionally it was difficult to measure the bedload we had collected but only in the cases of the well-rounded ones as we needed to bend the ruler round them to get an accurate measure of the length width and height.
Method 2 - The rock type lithology at the River Wharfe and Backstone Beck
Backstone Beck
Apparatus
- There was no equipment required for this investigation
Method
Again only two people were needed as this experiment was done on an even smaller scale. A random sample of pebbles was picked from a 10 metre stretch of Backstone Beck where we were working. Pebbles were picked from not only each bank but in the stream as well to give a varied sample. After collecting all of the 36 stones we required they were put back after determining what type of stone they were.
Diagram 1b
For this experiment no diagram was necessary as we were just finding out what type of stone the rocks were.
Logic
By picking the stones from different places in and out of the stream we were guaranteed a random sample that had diverse lithology and size.
Adversities
There were no major problems we encountered during our investigation.
Method 3 - The size and shape of the stones in the bed of the River Wharfe and Backstone Beck.
River Wharfe
Apparatus
- Thirty centimetre ruler
- Dilute Hydrochloric Acid (HCl)
- Pebble roundness chart
Method
To save time in this experiment it seemed wise to use the pebbles that we had already collected to analyse in terms of length (l) width (w) and height (h). Again only two people were used to carry out this test as it was fairly straightforward. The partakers were instructed when picking up the stones before to look up at all times to ensure that the stones they collected were random. The two people carrying out this test collected stones from the whole beach. By picking up stones in this way it meant we were guaranteed ones of different shapes and sizes i.e. some may have been weathered more than others depending on where they were in relation to each other. E.g. some may have been underneath other stones equalling less weathering. The length width and height of each article was measured using centimetres and millimetres because not only are they small measurements to use which are accurate but they are also easy to record and show on graphs. To determine the exact shape of a stone or piece of brick a pebble roundness chart was used.
Diagram 2a
Refer to diagram 2b for more information.
Logic
Using a pebble roundness chart to determine to shape of each object meant that the shaping of the rocks was not done on guesswork but fact. By using this chart for each rock it meant that they all got the same treatment therefore making it a fair test.
Adversities
Due to the monotony of this task some of the results may have been rushed as a result we may have some unbalanced results and maybe even some artificial ones. Because there is no way of telling this may have happened or it may not have.
Method 3 - The size and shape of the stones in the bed of the River Wharfe and Backstone Beck.
Backstone Beck
Apparatus
- Thirty centimetre ruler
- Dilute Hydrochloric Acid (HCl)
- Pebble roundness chart
Method
To save time in this experiment it seemed wise to use the pebbles that we had already collected to analyse in terms of length (l) width (w) and height (h). Again only two people were used to carry out this test as it was fairly straightforward. The partakers were instructed when picking up the stones before to look up at all times to ensure that the stones they collected were random. The two people carrying out this test collected stones from the each bank, in the water and on the brink of both for a 10 metre stretch from one point on Backstone Beck to another point 10 metres away. By picking up stones in this way it meant we were guaranteed ones of different shapes and sizes i.e. some may have been weathered more than others depending on where they were in relation to each other. E.g. some may have been underneath other stones equalling less weathering. The length width and height of each article was measured using centimetres and millimetres because not only are they small measurements to use which are accurate but they are also easy to record and show on graphs. After acquiring the stones they were compared to the pebble roundness sheet to resolve what shape and angularity they were.
Diagram 2b
Refer to diagram 2a for more information.
Logic
As there was no real beach at Backstone Beck it seemed commonsense just to take stones from everywhere. This turned out to work very well as taking stones from inside the stream as well as from out of it provided good varying results.
Adversities
Due to the way that the stream had formed there tended to be areas that had only one type of stone. When one of these ‘areas’ was discovered we stayed clear of it for the duration of the collection for the stones.
Method 4 - The velocity of the river for the River Wharfe and Backstone Beck.
River Wharfe
Apparatus
- Thirty metre tape measure
- A bag of oranges (Ten or more?)
- Stopwatch
- Transect line – Rope or string
Method
With use of the tape measure the first task was to measure a twenty metre stretch up the river that we would use as a race line for the oranges. We placed markers on either end of the twenty metre race line to indicate its start and finish. The rope was still tied to the tree on the south bank and the bench on the north bank left over from the channel width and depth experiment so that it need not be set up again. This would act as our transect line. After this we measured ¼ ½ and ¾ of the way across the bridge by use of the decorative metal posts on the bridge. By counting how many posts there were and then working out ¼ ½ ¾ of the way across we were able to drop the oranges from an accurate position. To make sure the whole experiment was fair we placed the start line around ten metres in front of the bridge so that the oranges had enough time to settle in the water and reach the same velocity as the water in the river was travelling. Once the orange had passed the start line it was timed until it reached the point of the transect line twenty metres on. We dropped five oranges from each point on the bridge (¼ ½ and ¾ across) by the time the experiment had ended so that we were able to work out an average which would provide us with accurate results.
Diagram 3a
Logic
There were multiple reasons for deciding to make the race line twenty metres long. Firstly we felt that this distance was the optimal length to use which would provide good results and also not take too long to complete.
It was also long enough to not be affected by the reaction times of the participants dropping the oranges from the bridge.
Adversities
Occasionally the oranges were dropped into the river at a wrong angle or at the wrong place completely meaning that they were sent of course sometimes hitting into the banks either side of the river channel obviously meaning that the process was void. This cost time and thus we had less time to do other experiments.
The oranges also encountered wildlife sporadically which meant we had to count the tests void.
This particular method was only able to measure the river flow on the surface of the river whereas a more detailed analysis maybe could have provided us with information about the velocity of the water beneath the surface.
Not so much a problem affecting the tests directly, but now and again oranges were lost down the river, if they were missed by people taking part in the tests.
Again not a particularly important case but the oranges were not all the same size, which could indicate a slight discrepancy to the results in the short term.
Method 4 - The velocity of the river for the River Wharfe and Backstone Beck.
Backstone Beck
Apparatus
- Metre Ruler
- Stopwatch
- String
- Tent Pegs
- Cork
Method
To begin with we needed to set up the race line. Due to the smaller scale of Backstone Beck we decided this to be only five metres long. The start line consisted of a piece of string suspended above the water held up by a tent peg either side of the stream channel. This set up was repeated for the finish as well. To ensure fairness we dropped the cork into the water a few metres in front of the start line. The cork was timed as soon as it passed the start line and the timer was stopped when the cork passed the finish line. This process was repeated four more times so that we were able to get an average for the results.
Diagram 3 b
Logic
The cork was dropped into the water a few metres before the start line to allow it to reach the speed that the stream was flowing before we started timing it. This way there would be no defective results.
To get even better results we repeated the experiment to obtain an average. In doing this we were able to pick out any dud experiments and repeat those we thought had gone wrong.
Adversities
The cork while moving down the stream was caught in a number of places. During the investigation we encountered many problems the biggest one being that the cork kept being stuck between the same two rocks on its way down. Occasionally the cork would get stuck in the plunge pools created by small waterfalls on the streams course. The cork also got stuck in a patch of reeds once. To make things worse, from time to time the cork would run into areas where the water was not flowing at all. Another problem similar to the one at the River Wharfe was that we were only able to measure the speed of the stream on its surface and not below. Unfortunately this experiment was much hit and misses. Although the results are accurate in terms of what happened on the day, they don’t give any real indication of what velocity the stream was flowing at.
Method 5 - Measurement of the valley slope profile at the River Wharfe and Backstone Beck
River Wharfe
Apparatus
- Abney level
- Two ranging poles
- Tape measure
- Metre rule
Method
We began measuring the valley profile from where the water touched the beach. Every disruption in the land was then measured all the way to the end of the field on the adjacent to the river (north bank.) On the south bank we discontinued measuring at the point were the grass ended and the second path started. To measure a section of land we carried out the following steps:- first we put a ranging pole in the place that the last break in slope occurred (the first one being where the water touched the beach.) Then we put the second ranging pole in the ground where we thought there was an incline or decline in the land. Once this had been established we proceeded to measure the angle of the incline or decline using the markings on the two ranging poles as a guide. To measure the angle we used an instrument called an abney level in which you looked through the opening in the instrument and lined up a bubble inside the spirit level within the device by using a rotating grip. Once the bubble had been lined up, the angle at which the land was slanted was shown on the side of the abney level. Then we measured the length between the two ranging poles with a tape measure. Both the angle of the land and the length of the slant were recorded onto a table. The first ranging pole was then moved to the next major break in the slope and the process was repeated. This whole procedure after being done on the north bank was then repeated on the south bank. In terms of measurements we used metres and centimetres for the length of each slope and degrees for the angle measurements.
Diagram 4a
Logic
Instead of using metre sticks in this experiment to measure the distance between the ranging poles we used a tape measure instead because the distance was seldom under a metre. We also had the choice of measuring the valley profile over a set number of distances e.g. every 1.5 metres or so. We decided against this idea because it would not provide clear results and a good picture of what the valley profile really looked like. Instead we chose to measure the distance of the slope when a break occurred. This way we got a good picture of the valley profile and accurate results to go with it.
Adversities
There a few problems that arose while we did this investigation. One that occurred frequently was that the person measuring the angle changed repeatedly, meaning that each person’s perspective of how to use to apparatus changes as well. In the long run this caused the results to bend around how the abney level was being used depending on who was measuring the angle. This obviously caused the results to become biased.
Another problem was that the ranging poles were not always lined up with each other and also they were hardly ever stuck into the ground the same amount as each other. This consequently changed the angle of the slope and the distance between the ranging poles from what it would have been, had the apparatus been set up correctly. As well as this the tape measure was rarely kept taught when measuring between the poles, again varying the distance each time.
At times, breaks in the land were not seen. This resulted in them being overlooked and not measured. In addition to all this, the ranging poles were generally tilted to one side when either the distance was being measured or the angle was being measured or both.
Method 5 - Measurement of the valley slope profile at the River Wharfe and Backstone Beck
Backstone Beck
Apparatus
Method
We started measuring the valley profile from where the water finished on each bank. On the west bank we laid the metre ruler on the ground with one end at the start of the bank and the other going up the valley side. We then placed the clinometre on top of the metre ruler and measured the angle of the slope. The process quite similar to using the abney level involved lining the bubble up with the line by twisting the grip on the side and reading off the angle from the other side. After these initial steps had been done we measured a metre up the valley side and did them again. We measured the new angle by the process I have just explained and carried on up the valley side for twenty metres. After doing this we continued on the east bank with exactly the same process.
Diagram 4b
Refer to diagram 4a for an idea of the setup.
Logic
We had the choice of measuring the angle of the slope at either every disruption in the grounds surface be it an incline or a decline or measure the angle of the slope every metre. In this case we decided to measure the angle of the slope at every metre as there were countless inclines in the land and it would have been very difficult to gain a good idea of what the valley profile actually looked like without having a huge number of results. It also would have taken such a long time we wouldn’t have had any time to do the rest of the investigations. We decided to measure at every metre because firstly it didn’t take as long and secondly it provided us with better results than what we would have had if we had taken the other option.
The use of a metre rule and a clinometre seemed more appropriate for this investigation as the scaled down equipment suited the environment as it too was a lot smaller than the River Wharfe. If we had tried to use a tape measure for this analysis there would have been a lot of increased difficulty that needn’t have been had due to the thick vegetation on either bank and in some parts steep and slippery slopes. It would also have been pointless as each distance was exactly a metre anyhow.
The clinometre appeared more apt for the job as it was much better at measuring angles over small distances.
Adversities
Thick vegetation on either side made it difficult to get up the valley sides and laying the ruler flat was also a problem in some areas as there were many bushes. Occasionally we found the ground to be wet which caused more problems trying to get up and especially trying to measure in these areas was a problem.
Method 6 - The pH of the water within the River Wharfe and Backstone Beck.
River Wharfe and Backstone Beck
Apparatus
- Litmus paper
- A pH scale
- Two sterilised testing flasks
- Universal Indicator
- Four coffee filters
Method
To sterilise the testing flasks I left them submersed in sterilising fluid overnight to kill any impurities and bacteria. I then washed them thoroughly with fresh water to return the pH level to seven (neutral.) I collected samples from both the River Wharfe and Backstone Beck. The samples were then both filtered to dispatch the liquid of any impurities that I had collected by mistake. Next I added universal indicator to each sample. This uncovered the pH and with help from a pH scale I was able to work out the exact composition of the substance. To provide alternative visual aids I tested both samples on litmus paper as well and noted the outcome.
Diagram 5a
Refer to Appendix 1
Logic
I sterilised the bottles as they had been used for other things beforehand and merely washing them out with water may have left some traces of material which could have either been acidic or alkaline disrupting the balance of the experiment. It was important that the flasks were both perfectly neutral in pH so that when the samples did go in that they were not affected. The coffee filters were necessary as when I was collecting the samples contaminations such as small bits of leaf and particles of soil got into the flasks with the river water.
Adversities
When I was collecting the samples from the River Wharfe and Backstone Beck small pieces of leaf and other things found their way into the flasks. It is possible that these may have been able to change the pH so this presented a problem. This was the only difficulty I had when doing this experiment.
Method 7 – Evidence of footpath erosion at the sites of the River Wharfe and Backstone Beck.
River Wharfe and Backstone Beck
Apparatus
Method
At each site there were footpaths mainly straddling the river or in the case of Backstone Beck the stream. Upon finding these trails I took two pictures of each from different angles and noted down a suitable description of the level of erosion to the footpath that was agreed by two people being a friend and myself. The results were decided upon by five separate individuals afterwards.
Diagram 6a
Refer to the method photos (Method 6 - results - photos)
Logic
To ensure that this analysis remained a fair test I felt it necessary to gain a second opinion concerning the footpath erosion. This way the results were based on the thinking of two separate individuals uninfluenced by each other rather than the thoughts of one which may have been biased. The results were also shown to five individuals afterwards to determine which photo portrayed the most eroded footpath.
Adversities
There were no major problems with this method but when taking the pictures it was sometimes hard to decide an area of footpath that was average to the others around it e.g. if we had taken a picture of a junction where a number of footpaths meet obviously this would have been used more than a singular one. We agreed upon an area of average footpath to the best of our ability.
Method 8 - Environmental quality/litter survey of the River Wharfe and Backstone Beck.
River Wharfe and Backstone Beck
Apparatus
- There was no equipment required for this investigation
Method
For this experiment I decided for there to be no set way of calculating the amount of rubbish in one particular area fairly so I came to decide that the best way of doing a litter survey would be to walk around for a set amount of time at each site and see how much rubbish I could find. This proved to work quite well and although I am not sure that the result I came out with was fair it was the best way of doing the survey.
Diagram 7a
None
Logic
I decided this to be the best way of carrying out this investigation because the alternate options were each unfair in some way or other. If I had instead just decided to take a look around and see how much rubbish was there it would have been unlikely that I could have given the same observation at each site.
Adversities
Initially I had a problem deciding how to carry out this method but once that was resolved there were no further inconveniences at either site.
Method 9 - Evidence of tourist honeypot site at the River Wharfe and Backstone Beck. (Bipolar analysis)
River Wharfe and Backstone Beck
Apparatus
- There was no equipment required for this investigation
Method
To find out how popular the two sites were I conducted a bipolar analysis survey at each site. I asked 15 people at each site to fill in a quick questionnaire which asked them five questions. The day was clear with sunny weather and the survey was conducted around lunchtime
Diagram 8a
None
Logic
By carrying out the survey at lunchtime and on a day which is favoured by the public I was able to gather my results quite quickly therefore being able to get to the other site in time for it to still be lunchtime. In this way it was a fairer experiment because the tests ran at about roughly the same time. I also tried to keep the questionnaire short and easy to fill in by asking only five questions so that the people I asked weren’t kept waiting too long. I feel this way that the results I gained were more genuine as people weren’t trying to rush through it. I made sure of asking a wide range of people and age groups so that I gained contrasting and varied results.
Adversities
When looking for people to fill in the questionnaire at Backstone Beck I found there to be a lesser amount of people there than there were at the River Wharfe. This caused the experiment to run over fifteen minutes.
Section 4 - Data Interpretation
Method 1
Before we carried out this method I hypothesised that the width and depth of the River Wharfe would be greater than that of Backstone Beck’s. The reason for my thinking is purely due to the scale comparison of the examples.
As the table and graph that refer to Method 1 shows the width and depth of the River Wharfe was shallowest at 6 centimetres 5 metres in from the south bank and deepest at 78 centimetres 12 metres in from the north bank. The results show that the deepest point of the river lies dead centre in the middle of the river channel 12 metres away from each bank.
The results gained from Backstone Beck show that the deepest part of the stream was only 1 metre away from the east bank at 23 centimetres whereas the shallowest part at 0.5 centimetres was pretty much in the middle at 60 centimetres from the west bank and 80 centimetres from the east bank. Different from what I expected the stream’s depth begins at each bank over 10 centimetres deep – 14 at the west bank and 22 at the east bank. There are also other abrupt jumps in depth all the way across the width of the stream, a few being 17.5 centimetres to 10.5 centimetres at 20 centimetres from the west bank and 9.5 centimetres to 1.5 centimetres 90 centimetres from the east bank.
The results that show the depth from the River Wharfe show that the deepest part of the river is more than 4 times deeper than the deepest part of Backstone Beck. The shallowest part however is less than that at Backstone Beck by only 0.5 of a centimetre.
When reading the results from the River Wharfe it came to me as a surprise to find that the deepest point was in the middle of the river channel as I expected it to be on the outside of the meander curve due to the water being faster flowing there.
The sudden rise and falls in the channel at Backstone Beck although unexpected, are justified by the large and angular bedload in the way. In the river’s upper stages the river erodes vertically rather than laterally causing the shape of the river channel to become quite deep. This again does not follow as Backstone Beck does not sport any particularly deep parts in its channel. This is probably due to the fact that we did not measure the width and depth in enough places or we might have not collected the correct type of data.
If I had the chance to do this experiment again I would make sure that instead of just measuring the channel width and depth in one place that I would measure it in several places therefore providing me with a greater picture of the stream. The irregularity of the bed at the River Wharfe was almost nothing compared to the bed of the stream at Backstone Beck. The four stages of deposition point out that large material is deposited by the river in the higher reaches – in this case being Backstone Beck. Gravel sand and silt carried as bedload or in suspension is deposited in the lower reaches – consequently being at the River Wharfe.
The diagram above shows that on the upper course either bank has a steep slope, at the middle course each bank is gentle sloping and on the lower course there are no banks but only a flood plain either side of the river channel. The upper course represents Backstone Beck and the middle River Wharfe.
My prediction is correct in terms of my results. Although my results do not prove them to be right, my prediction is supported by them.
Method 2
I did not make a prediction as such for this method as I was unaware of what matter I would find there. I was sure that there would be a larger variety of matter at the River Wharfe than at Backstone Beck and so this came to be my prediction.
The results I got from the River Wharfe show that the majority of the 36 examples we picked up using random sample were sandstone or varieties of it with 44%. With 39% limestone or varieties of it was the second most common rock at the River Wharfe. Brick (11%) Pot (3%) and Glass (3%) were the minorities totalling only 17% of the rocks when added together.
Rocks at Backstone Beck proved to be a lot more basic. We managed to find only two varieties here when carrying out the random sample. Again we collected 36 pebbles, 53% of them were shale while the remaining 47% were sandstone. The graph and tables that refer to method 2 show these findings but in an easier to compare format.
The number of different examples at the River Wharfe when chosen by random sample was greater than the number of rocks at Backstone Beck. The ratio of matter at the River Wharfe compared to Backstone Beck was 5:2 however it may not have turned out this way. One main occurrence in the results was that just under half of the examples picked up at each site were sandstone. This shows that sandstone occurs all the way through the upper and middle course of the river.
My prediction states that ‘there will be a larger variety of matter at the River Wharfe than at Backstone Beck.’ After looking at my results they support my predictions fully although this could have easily not been the case.
I say this because of the way the experiment was carried out. Because the matter had to be obtained by random sample this ensured that even though an outcome was likely it was not sure to happen. The greater minorities in the results being glass and pot only totalled to 6% of the total matter found at the River Wharfe. Out of 36 examples only one piece of glass and one piece of pot were obtained. Even though there were probably a few more examples of pot and glass the likelihood of picking one up via random sample were extremely unlikely. If this had been the case then the ratio of stones would have been 3:2 hardly making my prediction seem entirely justifiable. The same goes for Backstone Beck, except the chances of finding more or less different types of stone less probable.
After the initial tests were done, I went back to each site to see whether or not I could find any more stones of different varieties. I managed to find a number of new examples from the River Wharfe but only one new example from Backstone Beck. Refer to appendix 1 for more information.
(N. I have used the term matter in this section because not all of the things we picked up were rocks. Nonetheless, I did not use this term before this point. This is due to not knowing for sure whether or not I would pick up any objects other than rocks or pebbles. On following the booklet we were given, I decided to use the default title given for the first section and there on used the term rock or pebble until it was proven otherwise.
Method 3
Before we did the experiment, I predicted that the stones would be bigger at Backstone Beck than at the River Wharfe. From past-learnt knowledge, I knew that a slower running body of water would drop its load more readily than a faster moving body of water. As the volume of water at the River Wharfe is larger, I expected it to be flowing faster hence; I worked out the faster flowing course. The bedload at the upper course has also been weathered less due to the short distance it has travelled from either the source or places further on up the upper course. This was the basis for my prediction.
My results from the River Wharfe show that overall the matter found was smaller in size than the rocks and pebbles found at Backstone Beck. Averaging out at 6.3cm long, 5.9cm wide, and 3.6cm in depth the average pebble at the River Wharfe is 4.1cm shorter, 1.4cm thinner and 1.3cm deeper than an average pebble found at Backstone Beck.
On the graphs and tables in particular that refer to Method 3 you can see that most of the pebbles found at Backstone Beck were longer and wider than the ones found at the River Wharfe although many of them were not as short. This is due to the abundance of shale that can be found at the site of Backstone Beck. Initially sandstones, shale and clays are made from tiny particles of sand or clay eroded from past landscapes by wind or water and deposited in layers e.g. in the sea. Later they are uplifted to a position above sea level. These layers are beds or strata - separated by bedding planes which instead of breaking of in chunks due to the three weathering processes that are apparent in these areas (physical, in particular freeze - thaw, biological and chemical) they are instead broken off in layers. This occurrence causes their length and width to be of a high standing but then their depth to be low. Of course there are obviously other rocks in the stream but then referring back to method two 53% of pebbles found were shale while only 47% were sandstone. These findings would have clearly tilted the depth readings in favour of a lower value overall, the majority of them being shale.
If I think about my prediction logically then there is no doubt that it was incorrect. I stated that ‘the stones would be bigger at Backstone Beck than at the River Wharfe.’ This in whole was not true as the average depth of the stones at the River Wharfe was larger. I made the wrong prediction, but if I had thought about the situation comprehensively then maybe I would have seen that the real outcome was not too hard to see.
While carrying out this research we found that some pebbles were a great deal larger or smaller than the average sized rock or pebble. This could be due to number of reasons. Some pebbles may have been older than others thus they should have received more weathering. Others may have just had more weathering because of their position on the beach or in the river e.g. if a piece of limestone had been picked up from under the bridge at the River Wharfe I would have expected it to have been bigger than the rest of the pebbles because it has received less precipitation. The main factor however, is obviously how big or small the pebble was when it was first formed either by freeze, (thaw action most likely) or the other type of weathering.
Some pebbles when being observed, were seen to be a large amount more rounded or angled than the others. This was especially apparent at Backstone Beck. This is probably due to the large amounts of shale we found there, because shale is a very soft rock it breaks of its source e.g. the shale cliff, very easily. This means a lot of shale is breaking off a lot of the time (there are large levels of precipitation in this area causing this). Some of the examples we picked up may have been no less than a week old ensuring that they were very angular. As you can see on the graph that refers to Method 3 % of the shale found were describes as sub - angular, angular or very angular. Sandstone on the other hand does not break of its source so easily but it does disintegrate fairly quickly once separated by weathering, traction and saltation in particular. On the graph mentioned above % of sandstone found was described as sub - rounded, rounded or well rounded.
The matter collected at the River Wharfe was on the whole a lot more rounded than the examples at Backstone Beck. As well as having travelled further than the pebbles at Backstone Beck the greater velocity of the River Wharfe subjected them to larger amounts of erosion. Once deposited on the beach exposure to precipitation most likely rounded them further. The type of matter be it sandstone limestone, shale, brick, pot or glass further has an effect on how fast it will be weathered. Limestone, the softest of all the matter found is most likely to be affected by acid rain more than the others. Sandstone is easily broken making it more susceptible than the others to river erosion. Brick, pot and glass are fairly hard but their size depends entirely on how big they were to begin with.
Method 4
Before the experiment had began I expected that the River Wharfe would flow at a higher velocity than at Backstone Beck. My prediction was based on my knowledge that a larger body of water would run more efficiently and smoothly than a smaller one such as Backstone Beck. Also there are many obstructions for the flow of water to contend with on the upper course and because of these it would slow the current of the stream as a result decreasing the velocity.
The graph that refers to method 4 shows that the velocity of Backstone Beck on the surface is 0.0306 m/s whereas the River Wharfe flows at 0.35 m/s on the surface. This means the River Wharfe flows 11.44 times faster than Backstone Beck. When taking results down at the River Wharfe we found that the flow was fastest at a quarter of the way across. The average time for an orange to travel 20 metres a quarter of the way across was 78.6 seconds while half way across was 44.4 seconds and three quarters of the way across was 48.8 seconds. This finding is in all probability is due to the fact that the river occurs on a meander and a quarter of the way across the channel is where the outside of the meander lies. From past knowledge I know that the current is fastest on the outside of the meander curve because the river channel is deeper there - on the inside its shallow so the current is slower.
At Backstone Beck there were many meanders in the stream’s course but none that actually affected the flow in a big way, so how fast the cork actually went depended on which path it took. At the upper course the channel was filled with big rocks and boulders. Many of these caused the cork to get stuck consequently slowing it down. There were also many slack pools and eddies where the cork even stopped occasionally completely. These occurrences also affected our results.
When we did the experiment to find the velocity of the River Wharfe I was concerned that the method we decided on doing wouldn’t be effective or accurate enough to provide us with valid results. During the experiment and looking at our results now I have abandoned that opinion because I think our results provide an excellent interpretation of what velocity the river was flowing at on that day. They show that the flow is fastest on the outside of the meander curve and slowest half way across. Although this doesn’t follow the textbook description of how a meander operates the graphs and tables that refer to method 1 show that the river was deepest exactly half way across which in theory matches with my results gained from method 4. I mentioned earlier that the flow was fastest on the outside of the meander curve only a quarter of the way across. If the deepest part of the river lies in exactly the middle and water flows fastest at the deepest point then in theory the water should flow fastest in the middle of the river channel. In the case of the River Wharfe though this is not true. The photo on page 4 shows that the start of the meander just before the bridge is in fact a separate but much more harshly curving meander than the long gently curving one ahead that is shown. It is likely that even thought the deepest part of the river is in the middle, the water on the outside of the meander has to travel a lot faster on that first harshly curving meander to keep up and then continues to travel fast out of momentum onto the 20 metre stretch that we covered during our velocity measuring experiments. I feel that this is a valid reason for the water being fastest on the outside of the meander we studied albeit the channel was deepest in the middle. I have taken into consideration the culvert that joins the river inside the 20 metre stretch we working on but on the day of testing it seemed quiet making it unlikely that it diverted any of the oranges in a large way. Any experiments that went wrong, or were disturbed by animals or plants, were repeated to ensure that our results were constructive.
Method 5
I predicted that the results from this experiment would show that the valley sides at Backstone Beck would be steeper than the valley sides at the River Wharfe. The basis for my prediction is that as I already knew Backstone Beck featured interlocking spurs and a particular trait of these is that mainly places in the upper course of a river encompass these. This fact leads to the basis for my prediction as I knew already that instead of eroding laterally places in the upper course eroded vertically and in turn this process creates steep valley sides. The results that we obtained from the River Wharfe shoe that the north bank was almost horizontal as the reading for the angle of slope averaged out at a mere 8.4° with the highest angle only 30° and this only lasted for 0.41 metres. Between sections I - J and J - K there was a small levée where deposition had occurred during a flood. The result from the south bank show that it’s average angle for the whole slope was slightly bigger by 2.1° at 10.5°. However the steepest angle for the south bank was only 22° although it lasted for five metres. We also found a section of slope at an angle of 13° which lasted for 10.83 metres.
The results from Backstone Beck show that the slopes are quite varied in their results with the difference in slope angle between the two being 10°. The west bank averages out at 42° being the steepest of the two. The steepest point of the west bank is 72° while the steepest for the east bank is only 50°. The more gentlest slope of the two banks is 8° on the wets bank whilst the east bank is only 1° higher at 9°. The valley sides have completely different slope angles as well as when it comes to where the steepest parts are on the slope. The steepest angle 72° on the west bank Is a mere 3 metres from the stream while the steepest point on the east bank (50°) is 14 metres from the edge of the stream.
The banks at Backstone Beck were a lot steeper than either of the banks at the River Wharfe. Including both banks at each site the largest angle of slope at the River Wharfe was 30° comparing to 72° at Backstone Beck. The lowest angles also are further apart than I imagined with -5° at the River Wharfe and 8° at Backstone Beck. These major differences owe to one factor that is different between the two sites.
The valley sides at Backstone Beck although completely different in terms of angles and where the steepest parts prove to be a lot more symmetrical than the banks at the River Wharfe. This is due to the lack of human influence at Backstone Beck and the profusion of it at the River Wharfe. Land use there is a lot more prominent by visual terms than it is at Backstone Beck.
The main reason for the results being so different at each site was the different types of valley that appeared at the locations. When at the River Wharfe we studied and measured a U - shaped valley whilst the one at Backstone Beck was V - shaped with interlocking spurs. These shaped valleys are typical of a site at a upper and lower course location and our results showed that Backstone Beck and River Wharfe had these particular shaped valleys.
I expected to find a flood plain at the River Wharfe mainly on the north bank because the river is known to flood a lot and that the area we were working on was known to flood quite regularly. This was certified when I found that a lot of the north bank consisted mainly of alluvium and load that the river had deposited there in times of flood. This is not the case however on the south bank as there it is quite steep at does not feature any where near as much erosion and the north bank. Human influence over the years has most probably contributed to the south banks appearance. Up the slope both before the path and after it, the incline goes up steadily until it reaches the top, as you can see form Method 5 - Results - Table.
There is also evidence of a natural levée on the north bank of the river which I did not predict. Levées are natural embankments of silt along the banks of a river often several metres higher than the flood plain although in this case only 1 metre higher. Levées are formed on rivers that flow slowly, carry a large load and periodically flood.
The formation of levees.
I predicted at the beginning that the River Wharfe would encompass a prominent U - shaped valley although it was not as U - shaped as I predicted it would be. I also predicted that the valley at Backstone Beck would be V - Shaped. This also turned out to be true and my results support this.
Method 6
I thought initially that both of the sites would be acidic due to acid rain which affects the pH of the water. My view change when I realised that the rock son the stream or river would or could affect the pH of the water. Thus I predict that the water at Backstone Beck will we be slightly acidic probably around 6.5. My prediction is based on the results of method 2 which show that there are no alkaline rocks in Backstone Beck. If the river has not been affected in this way than acid rain affected the pH. I predict that the River Wharfe will be slightly alkaline but not much as both cases will have affected the water being acid rain and the proportion of alkaline rocks found at the River Wharfe. Method 2’s results show that 39% of the rocks there are limestone. This indicates that the water will have been affected but the counterbalance of acid rain will have neutralised the pH. I predict that the water there could be either 6.9 7.0 or 7.1 in pH depending on the acid in rain to the proportion of alkaline in the rocks.
The results table and graph that refer to method 6 show that the pH at the River Wharfe was 7.1. Quite different was the pH at Backstone Beck being 6.2, 0.9 apart from each other on the pH scale. This result from the same river was surprising as the two pH’s are quite apart in value.
Quite surprisingly my results do in fact match my prediction. My theory concerning the pH of the water at each site was based merely on an educated guess. I was not sure whether or not the limestone in the water would even affect the pH at the River Wharfe because part of my method was to filter the water from each site first to remove any impurities. Unless the alkaline substance had chemically bonded with the particles in the water to become part of it the alkaline substance should have been filtered out. I was surprised to see this outcome when it became apparent.
Method 7
I expected that footpath erosion would be greater at the River Wharfe because I have been there before and each time there have been a considerable amount of people around the site of at which we conducted our experiments. Initially I had never heard of Backstone Beck so I expected there to be a lot less people there. My prediction states that the footpath erosion at the River Wharfe will be greater than that at Backstone Beck.
My results in the form of photos show the nearest footpaths to the sites that we studied. Although there is a suggestion of unfairness here to what is a measure of how used a footpath looks to ensure a fair test I consulted 5 people including myself to which photos showed the most eroded footpath. My mini survey turned out as below.
Backstone Beck River Wharfe
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Three people including me voted that they thought that the paths at Backstone Beck were eroded most.
As you can see on the Backstone Beck photo (Method 7 - results - photo) it is clear that the path that straddles Backstone Beck has been overused and there remains nothing except earth and a few spots of grass on the path. The paths at the River Wharfe look much the same although the earth is darker and there are many occasions where the grass has grown back onto the path in places where it hasn’t been used. This would suggest that the paths at Backstone Beck are used more and that more people visit there more often but this statement has already been proved wrong in the bipolar analysis. I think the reason for this anomaly in my results is due to the layout at the two sites. At Backstone Beck there are far fewer paths and less space to walk. Unlike the River Wharfe there are some points in the path at Backstone Beck which disallow you from leaving the path owing to the thick vegetation either side. This occurs over most of footpaths actually and is probably the main reason for the greater footpath erosion there. At the River Wharfe alternatively there is a large space of grass surrounding the footpath and although the footpath is there it is unlikely that everyone who walks along near there would use it.
If I was to do the experiment again I would try to make it more impartial by making sure that the paths we chose at each site which are much more identical to each other. This way the results would be a lot more beneficial.
Method 8
I carried out this experiment after the skate park had been built whether as the initial tests had been done before the construction. For this experiment the presence of a skate park would greatly affect the results. I predicted for this experiment that the site with the greater rubbish would the River Wharfe owing to a multiple amount of factors.
Even though a number of litter bins were apparent in the area around the River Wharfe (four) I did still spot numerous amounts of rubbish festering around the benched areas and sitting stones. Not to blame anyone in particular but I am sure this is due to the recent opening of a skate park not too far from the river itself as when we did the initial experiments there before the skate park was built I did note a considerable lack of rubbish around the area. However, it is always possible that an alternative explanation may have happened and in fact the rubbish may have been caused by the general public. I did mention there to be four bins around the River Wharfe three of these unfortunately lie in the skate park. Due to usual occupancy of the skate park members of the public may find it intimidating to use the bins in the skate park as the fourth one I mentioned wasn’t directly near the benches but in actual fact quite a way away from them. Being this the case people may be inclined to discard their rubbish inappropriately
When visiting Backstone Beck I found there to be little to no rubbish at all. I spotted a pieces stuck in the heather but none on the footpath. This could either be down to the strong winds blowing it all to a different location or the different types of people who visit this area. In reference to the bipolar analysis that I did 100% of the people who I met at Backstone Beck were either adults or older citizens. Being this sort of age group they tend to care more for the environment than the average adolescent despite the complete lack of litter bins in this area.
I have not drawn up a method table as such for this experiment as I have no solid figures or diagrams but only photographic evidence although this format of results suits this analysis far more than any of the other formats.
My results entirely support my prediction.
Method 9 – Bipolar analysis
Prior to the experiment I predicted that the results of the Bipolar analysis would show that people preferred Backstone Beck to the River Wharfe in all categories of comparison.
My results indicate that for each question asked on the questionnaire Backstone Beck is rated more highly for each category. The results show that when asked 100% of people thought Backstone Beck was quiet whereas at the River Wharfe only 10% gave the site a plus rating. Again at Backstone Beck 100% of people asked thought it was clean, empty, and beautiful. Statistics obtained at the River Wharfe said that 80% thought the River Wharfe was dirty, 88% thought it was crowded and 95% thought it was beautiful. These results compared show a great significance in public opinion towards Backstone Beck and a feeling that River Wharfe is lovely to look at but is being depreciated by noise, rubbish and overcrowding. Overall 100% of people asked spoke in favour of Backstone Beck where only 34% praised River Wharfe although both parties thought that each site was very beautiful.
To ensure that this experiment was kept completely fair then I should have instead asked the same people at each site. This was at the time impossible to do but if I had done the experiment again then this is what would have been the best way to carry out a bipolar analysis. My results totally supported my prediction.
Section 5 - Evaluation
I successfully identified 10 characteristics of the two rivers which provided lots of good evidence to achieves the aim of my study this being to find out how the River Wharfe’s characteristics change from its source to its middle course. The 9 characteristics that I studies were :-
- Channel, width, and depth of the River Wharfe and Backstone Beck.
- The rock type lithology at the River Wharfe and Backstone Beck.
- The size and shape of the rocks in the bed of the River Wharfe and Backstone Beck.
- The velocity of the river for the River Wharfe and Backstone Beck.
- Measurement of the valley slope profile at the River Wharfe and Backstone Beck
- The pH of the water within the River Wharfe and Backstone Beck.
- A comparison of the footpath erosion at the sites of the River Wharfe and Backstone Beck.
- Environmental quality/litter survey of the River Wharfe and Backstone Beck.
- Evidence of tourist honeypot site at the River Wharfe and Backstone Beck. (This method ties in with the Bipolar analysis study)
The two sites were different enough to provide a clear indication of the differences of a river at it’s lower and upper course and the River Wharfe and Backstone Beck proved to be good examples of this.
I collected enough data to draw up a variety of tables and graphs which showed comparisons of the two sites clearly and in detail.
Both sites we studied were easily accessible and required no transportation to get us there. They were both safe as no real danger was present and no one found any problem in the process of any investigations. Although Backstone Beck was a little hard to navigate no one was hurt in any way. We made sure that the people carrying out method 1 at the River Wharfe were competent swimmers as a precaution despite the fact that the river was very low anyway.
Both rivers were clean at the time of investigation as well which made it easier when doing the various experiments e.g. rubbish that could have gotten into the river may have affected the results of method 4.
Group work was very successful as there were very little disputes over the experiments. Every body worked well with each other and got on with things.
The methods we used were easy to follow and nobody had a problem with understanding them. The equipment we used was bog standard and any equipment that was specialized we already had so the experiments were cheap to carry out as well.
The methods also explored all the right elements of rivers to give a clear and wide understanding of each site and it fundamentals. They were highly appropriate to investigate the differences between the two rivers.
In no way did we damage or harm the environment during the course of our investigation. All rubbish that had accumulated was placed in a bin afterwards. All the stones that were analysed were put back on the beach. Although some ducks were disturbed by passing oranges none were seriously hurt and no other wildlife was affected.
Overall I am happy with the data I collected for my study, however there are aspects of the data collection which may limit the conclusions that I can draw.
We only visited the river/beck once which may have affected the results of a few particular methods. If we had gone say in the winter than the velocity of the river/beck would have been higher, as would have the depth plus many other factors would have changed.
I think the equipment we used did in no way depreciate the results that we gained from using it. I don’t think that if we had used more advanced technology that it would have bettered our results because most of the experiments used simple technology anyway and hardly any experiments required equipment that couldn’t have been easily acquired. If we had, say, done another method which aimed to find the velocity of the river 10 centimetres below the surface then better equipment would have been needed but for the tests we did I think the apparatus we used was fine.
Each of the methods we carried out presented problems. One or more inaccuracies were always present either avoidable or unavoidable. Method 1 caused problems with measuring the depth, with the water coming up onto the ruler plus also the bedload in the River Wharfe made it difficult to push the metre ruler to the bottom of the bed. Method 2 proved bias as all the pebbles we analysed were taken from the point bar and none from within the river or the south bank. Method 3 depended entirely on who was analysing the rocks and although we only had one person analysing them, how far was their interpretation of the rocks from perfect? Method 4 shunned any possibility of fairness due to the fact that the oranges had to be dropped into the river from a height. There was no way any of the oranges that were timed at the River Wharfe were placed and stayed in the line they were supposed to during the whole course of the 20 metres that they were timed for. At Backstone Beck as well more problems occurred when timing the cork since almost every run we did the cork got stuck behind a rock or pulled into a plunge pool. Method 5 was made harder by dense vegetation found at Backstone Beck causing great difficulty in placing the metre rule on the ground. Another discrepancy involving method 4 was that instead of using the same object to determine the velocity two different objects, a cork and an orange were used. This raised the question ‘Is it fair to compare results’ when this is the case. Perhaps we should have used an object which suited both situations.
Some of the methods in particular methods 2, 3 and 5 relied on a subjective decision. By relying on someone’s opinion you are assuming they are right when in fact they could be totally wrong. When more than one person is analysing in the same group the results are based on the individual opinions of the participants. Both these scenarios are bias and provide inaccurate results.
The aim in first place was to find out how the River Wharfe’s characteristics change from its source to its middle course. We didn’t in actual fact do this as the two sites we studied were a river and its tributary. It surely would have been better to study the upper and middle sections of the same river. At least this way we would have actually carried out the aim correctly.
In order to improve and extend this study I would for method 1 have taken more readings say measured the depth every ½ metre or so or in the case of Backstone Beck every 5 centimetres instead of every 10 centimetres. This way we would have gained a better picture of the river/beck bed cross sections and hence a more intricate diagram for each.
For method 2 to add another aspect to the experiment we could have also weighed the rocks which would have showed us how heavy the rocks are in conjunction to other types and varieties plus also which rocks are likely to travel further than others when being transported down stream due to their weight.
I can’t think of any way in which method 3 could be improved as it was simply a case of measuring the stones and taking the results down. To enhance the results using a more accurate ruler or a device that showed the correct length, width and height more easily would have been useful.
Method 4 depended mostly on where the orange was dropped or how often the cork got stuck. These two problems were unavoidable with the equipment we had been given. To ensure completely accurate results we could have instead tied a piece of rope five metres in front of the start line, measure the rope and mark the same markings onto it (¼, ½ and ¾) or possibly fifths or sixths of the way across. Then just get someone to put the oranges in the right place. This alternative method would make the experiment impartial and also provide more results if we had taken the velocity down over an increased number of distances across the width of the river. The cork on the other hand had nothing that could be done to remedy the problem of it getting stuck except of course moving the bedload which would have been impossible.
Method 5 could have been improved if we had researched the land use at Backstone Beck more thoroughly and compensated by using more adept equipment. Thick vegetation on the valley floor made it difficult to measure the various slope angles thus affecting the results.
Method 6 would have benefited from having more tests done to the water which would have determined it’s composition, exact pH, contents, age e.t.c. Of course this would have required a lab and numerous amounts of machinery which I have no access to.
Method 7 & 8 have no way of improvement as already they are very simple and have little room for adjustments. One possibility is that method 8 could have done in a different way as such but as I have already discussed I doubt there was any way of doing the experiment better and at the same time keeping the results accurate.
Method 9 might have been bettered if I asked more people to fill out the questionnaire as more opinions would give a more averaged out answer to each question. Additionally I could have carried out the survey on a different day, week or month and on days where the weather was different.
If I had done this whole trial again then I would do it exactly 6 months in advance of when I had done it before. This being in winter would supply me with the most contrasting results that I could have. I could also have done the experiments at a different part of the river, perhaps at the lower course. This would give me an idea of what it was like downstream in more detail. As well as doing this I might have compared it to a different river to see if what I have found out is common among rivers. I could also use different aspects of the river to study to provide me with more results and give me a better understanding of how rivers work.
Overall, I think this experiment was a success. 9/10 predictions I made were correct and the one I did get wrong was due to a fault in the method. I have learnt a great deal and done things that I feel have improved me in general. Despite the limitations, I have done a good study that provided data which on the whole supported my predictions.
Section 3 – Data Presentation
Glossary
Alluvium - River deposited material (sand and silt.)
Attrition - Process of river erosion whereby the load rubs against itself.
Channel - The feature in which a river flows.
Chemical Weathering - Break up of rock by processes such as solution causing changes in the minerals that form the rock.
Confluence - Where two rivers meet.
Corrosion - Process of erosion caused by the solution of minerals e.g. salt.
Delta - Often triangular shaped flat land jutting out into the sae at the mouth of a river.
Discharge - Amount of water flowing in a river, measured in cubic metres per second (cumecs.)
Distributary - Stream channel in a delta resulting from division of a larger channel.
Drainage Basin - Area of land drained by a single river.
Estuary - Drowned river mouth in a lowland water.
Freeze - thaw - Break up of rocks by alternate freezing and thawing of water trapped in joints of the rock.
Hydraulic Power - Process of coastal and river erosion caused by the force of water.
Hydrological Cycle - Cycle of water between the land, air and sea.
Interlocking Spurs - Spurs of high land which overlap in the upper part of a river valley.
Meander - Bend in the middle and lower course of a river.
Meander Scar - Dried up oxbow lake.
Mouth - Where a river enters the sea or a lake.
Ox - bow lake - Semi - circular lake formed by a meander being sealed off from the main course of a river.
Physical Weathering - Break up of rock by processes such as freeze – thaw without any changes in the minerals that form the rock.
River Cliff - Steep river bank of the outside of a meander.
Saltation - Small particles ‘jumping’ along the river bed.
Sedimentary Rock - Rock that usually begins as sediments, usually laid down under water.
Slip - off slope - Gentle slope on the inside of a meander.
Solution - A form of chemical weathering.
Source - The starting point of a river.
Suspension - Small particles of clay and silt carried along in a river.
Traction - Boulders rolling along the river bed.
Tributary - Small river which flows into a larger river.
V - shaped valley - River valley in it’s upper course, steep - sided and narrow.
Velocity - The speed of a river’s flow.
Volume - The capacity of a river.
Watershed - The imaginary line that surrounds a drainage basin.
Weathering - Breakdown of surface rock by weather without any movement of the rock.