The research I have carried out to test if the statement Stretches of a river can be very different in terms of their processes and landforms has proven to be correct for my study area which was Ty ny Berth which is in Snowd

0.27

7.4

Site 6

7.40

0.22

0.32

0.35

0.31

0.17

0.27

8.1

Site 7

24.00

0.16

0.55

0.75

0.18

0.33

0.39

27.00

From the site data it shows that the river depth increases as you go down river. This ties in with the Bradshaw model as it states that river depth increases as you go downstream. This also agrees with the sub-hypothesis that this channel will get wider and deeper the closer to the mouth of the river you go.

However, there were a number of flaws that we came across while we were trying to test out our hypothesis. These included the rocks that were in the river which would affect the river velocity.

One theory which states that rivers change from source to mouth is Bradshaw's theory, which visually details the changes that occur downstream along the course of a river. However only part of his theory applies such as load particle size will decrease as you go from upstream to downstream

Bradshaw said that velocity should increase as you go downstream, however looking at my data I can see that there has been an anomaly in site 2 as this doesn't fit with the Bradshaw model. This may due to human errors when using the flow meter.

This is the mean particle volume across the seven sites. It seems site 3 is an outlier to the rest as it may be due to human error. So this does not fit with the Bradshaw model

The channel will get wider and deeper the closer to the mouth of the river you go

Firstly, we wanted to measure the width and depth of the river. This was by using a metal chain and also with a tape measurer. Firstly we took the chain from one point from a river to the other side then we used a tape measurer to measure the depth of the river and we used a metre stick and inserted it into the river to measure the depth of the river. We used at least 5 people in different points of the place in a straight direction that we measured for the width. We decided the point to place people in by firstly measuring the river and then calculating how to, evenly as possible, place each person across the river.

We did it because it made our sampling method systematic across the seven sites; we chose five points in each site and used random sampling to pick 2 stones in each point. Also we used the metal chain to measure across the river and also to measure all the bumps in the river.

We chose 7 sites to get our systematic sampling from because it made our data more accurate as it allowed us to measure the size of rocks and also the change in width and depth across from the upper course to the lower course of the river.

A limitation that I came across was that while we used the metal chain to measure the width of the river, due to the velocity of the river, was that it could have made our results inaccurate as the chain could have been moved slightly by the river. However it doesn't really affect my results that much as the river is getting wider as we go closer to the mouth of the river. Another limitation to our data was that we couldn't use the metal chain for site 7 as it was too wide and also the metre stick was not long enough to measure in some sites.

A way to improve these limitations will be to stretch the chain as to make it more accurate so the river will not make it move too much. I could also use a ranging pole instead of a metre stick then measure the ranging pole with a tape measurer. This affected our overall results as we were not able to accurately measure site 6 and 7 so it made our results invalid.

Velocity will decrease as the river goes down stream.

We then wanted to measure the velocity of the river. This was achieved by using two different methods. The first method was using the 10 metre downstream and measuring how long the river takes to transport the ball from start to finish. Also we used a flow meter which measures the velocity per second of the water. This was done by 8 people. 2 people were at the starting point of the 10 metres and were dropping the balls and the other 4 were at the finish point and where catching the ball at the 10 metre point. We used the same ball to make the test more accurate.

To find this out, we used balls because it was easier to float on the river and measure how long it took for it to go 10 metres. Also we used the same ball(s) so that the test would be reliable and more accurate.

As with the previous sub-hypothesis we chose 7 sites to get our sampling from because it made our data more accurate as it allowed us to measure the size of rocks and also the change in width and depth across from the upper course to the lower course of the river. This proved to be true as in my data it showed that my width increased from site 1 to 7 and also the mean depth from site 1 is smaller that the mean depth in site 7.This links to the Bradshaw model as it shows that channel width and channel depth.

A limitation I came across while using the ball method was that in many instances the ball was stuck by a rock in the river. Also because people were in the river at the time that we were conducting the experiment, it would affect the river current and lead to an inaccurate result, however it didn't affect our results as it also links to the part of the Bradshaw model which states that 'average velocity' will increase from upstream to downstream

In order to prevent this problem from arising, a way to improve it could be by firstly for the ball method we could instead use a flow meter as it more accurate and as less people will be in the water doing the experiment; it will not affect the river current.

Particle load will get smaller, the closer to the mouth of the river you go

In the point that each person was at, we collected 2 rocks in each point where a person was standing and there was 5 people. We then measured the length and width of the rocks and Joy recorded them down in a datasheet on a clipboard. We used a ruler to measure the rocks.

We took those 2 rocks in each point because it made our data more accurate and helped us get to our conclusion.

0 stones were chosen randomly across each site from 5 points in a site. We picked 2 stones from each point randomly; making sure that the intervals between each point was the same to keep the experiment accurate. I noticed that the deeper we went into the river, the larger the surface area of the stones. I believe that is due to the erosional features that take place such as abrasion and attrition. Abrasion is basically the mechanical scraping of a rock surface by friction between rocks and moving particles during their transport by....running water and erosion.' This would make the stones smaller and smoother and also in conjunction with attrition, which is 'a form of coastal or river erosion, when the bed load is eroded by itself and the bed', would make it even smaller and smoother. This links with the Bradshaw model as it states that 'load particle size' will decrease as you go from upstream to downstream.

Erosional landforms will be located near to the source and depositional landforms will be closer to the mouth.

I took pictures of landforms that we discussed such as a meander. We also took pictures of a riverbank and depositional landforms.

We took pictures because it would be easier for us to annotate it and label the correct parts of the river and also landforms such as a levee or a meander.

FIELD SKETCHES ANNOTATIONS PHOTOS

*Systematic samplings

*we chose location that the photos will be taken from and then annotate to show the difference of the landform'

Looking at my sketches for site 1 and 7 I can see that from the upper course of the river we could see depositional/erosional landforms such as meanders. This may be due to Eros ional processes such as abrasion, which is when 'sand and pebbles are dragged along the river bed, or knock into it by saltation, wearing away the bed.' As we moved closer to the source of the mouth we saw the formation of a waterfall. This may be due to erosional processes such as hydraulic action. This will wear away at the soft rock until the hard rock has nothing to support it and it breaks off. This will result in the water flowing over the rock and creates a waterfall. A waterfall is made where fast-flowing water is forced into cracks, breaking up the bank over time. There was more undercutting at the source and more deposition at the mouth. This is because at parts in the river after it turns a sharp corner and the sides are eroded, the river can lose energy and deposit some of its load.

Equipment we used:

we used a plastic ball in order to measure how long it took to get to a certain distance over the river

we used a stopwatch to measure how long it took the ball to get to a certain distance on the river

we used a metre stick to measure the depth of the river at each point from upstream to downstream

we used a metal chain to 'try' and measure the width of the river at each of the seven points however we couldn't measure the width of site seven as it was too long.

In conclusion the things that Bradshaw stated that validate my results such as 'load particle size' will decrease from upstream to downstream and also 'occupied channel width', 'Channel depth' and 'average velocity' will increase as you go from upstream to downstream. However, there were some outliers that I came across while assembling my data such as the mean velocity in site 2 and the mean particle volume in site 3. These didn't fit with the Bradshaw model. They may be due to human error as in the mean velocity in site 2 the flow meter may not have been used accurately and as for the anomaly in the mean particle volume in site 3, this may be because the stones that were picked up might have been from an area of deposition while the others that fit with the Bradshaw model may have been picked from an area of erosion.

My research will test if this statement is correct for my study area?

The research I have carried out to test if the statement 'Stretches of a river can be very different in terms of their processes and landforms' has proven to be correct for my study area which was Ty' ny' Berth which is in Snowdonia in Wales. It is true because of the following reasons which are the fact that the upper course has depositional landforms has meanders while as we move closer to the mouth of the river we can see that depositional landforms such as waterfalls and floodplains start to appear. And also we can see that the interlocking spurs that were visible at the uppercourse of the river became wider as we moved downstream and floodplains began to appear.

Lopez Okhiai

olopez Page 1 05/02/2012