Does Wycollar Beck fit the Bradshaw Model

Question 1

What does the Bradshaw model state?

Answer 1

Discharge will increase downstream, load particle size will decrease downstream

Question 2

Method for measuring velocity

Answer 2

Measured 5m long the bank and timed how long a dog biscuit took to travel this distance, dividing by 5 to give m/s. Repeated every 400m for 7 sites.

Question 3

Method for measuring load particle size

Answer 3

Used a tape measure along the width of the river, used a random number table to pick points to sample the load on the river bed, put a 1m stick at 10 points across the channel and picked up sediment below it. Measured its axis and did this every 400m for 7 sites.

Question 4

Why use this method for velocity?

Answer 4

Dog biscuits are biodegradable and have a similar density to water so their velocity is similar too, they aren’t affected by wind

Question 5

Why use this method for load particle size?

Answer 5

Measured the axis to ensure consistency and sampled 10 pieces to ensure enough data was collected to give a representative sample

Question 6

Sampling method?

Answer 6

Systematic sampling- data points collected every 400m and divided channel into tenths for load particle size, pragmatically modified if these points were unsafe or inaccessible

Question 7

Links to research question (velocity)?

Answer 7

Shows how velocity changes along the river and the relationship between velocity and location

Question 8

Links to research question (load particle size)?

Answer 8

Shows relationship between location and load particle size

Question 9

Conclusion/findings?

Answer 9

Velocity at site 7 increased by 500% compared to velocity at site 1 showing Wycollar Beck fits the Bradshaw Model. Particle size does not fit the Bradshaw Model because there is no clear trend due to geological differences and human modification of the banks. Therefore it partially fits the Bradshaw Model.

Question 10

Where was the anomaly for velocity?

Answer 10

Anomaly occurred at site 4, shown on a scatter graph, because the river flows through a pool of water and is therefore slower.

Question 11

Why use a scatter graph?

Answer 11

Scatter graphs allow for a visual representation and correlation to be shown through a line of best fit, also shows any anomalies.

Question 12

Why did load particle size not match the BM?

Answer 12

Due to human intervention along the bank so the river eroded bigger rocks in walls further downstream or we may have been unable to hold and measure smaller rocks so we only measured larger ones.

Question 13

Why use an ArcGIS map?

Answer 13

Clear, easy to read, visually represent data and the base map allows us to start to explain geographical reasons for variations

Question 14

Problems with method of velocity

Answer 14

Dog biscuits got stuck on banks/ rocks/ plants, varied pools and rapids affected results

Question 15

Solution?

Answer 15

Use a flowmeter or measure a longer distance along the river

Question 16

Problems with method of particle load size?

Answer 16

Anomalous rocks, too big and heavy sediment pieces, too fine sediment, not being able to measure with 1m stick

Question 17

Solution?

Answer 17

Use a Vernier Calliper, measure rocks while in the water if they are too heavy, sample sediment with spade and use sieves to section sediment into sizes.