familiar fieldwork - river Tillingbourne

Question 1

why processes are affected by the energy of a river and how can we measure this

Answer 1

erosion, transportation and deposition

measure the velocity and discharge

Question 2

three changes expected to observe throughout the river and why do we see these changes

Answer 2

• upper course -> narrow channels, large bed load and landforms like V-shaped valleys
• middle course -> channels widen and deepen, landforms like meanders
• lower course -> wider and deeper channel, landforms like floodplains and levees

see these changes because discharge increases and particle size decreases -> traction makes them smaller

Question 3

location of river Tillingbourne

Answer 3

flows between dorking and guilford in surrey

Question 4

size of the river Tillingbourne

Answer 4

length - 19km

drainage basin - 59km^2

Question 5

is the river small or large scale

Answer 5

small scale

Question 6

how might the size of the river impact the discharge

Answer 6

discharge is fairly small -> smaller river -> less risks

Question 7

how much of the drainage basin in high or low permeability

Answer 7

high - 90.39%

low - 0.95%

Question 8

how much of the drainage basin is covered by woodland and how does this impact the river

Answer 8

49.69%

protects river from too much discharge
-> roots suck up water
-> water interception

Question 9

how much of the drainage basin is covered by grassland and how does this impact the river

Answer 9

23.2%

keeps discharge low
-> absorbs water

Question 10

how much of the drainage basin is covered by urban areas and how does this impact the river

Answer 10

9.9%

impermeable surface
-> causes flooding

Question 11

which sampling strategy could we use and why

Answer 11

systematic so we can measure the river in even intervals

Question 12

title of investigation

Answer 12

to investigate how the river Tillingbourne changes downstream

Question 13

data presentation

Answer 13

• cross section (width and depth)
• bar graph (velocity)
• annotated photo
• scatter graph (mean width/distance from source)

Question 14

primary data

Answer 14

velocity, width and depth, field sketch

Question 15

secondary data

Answer 15

landuse survey, OS map, FSC data, environment agency

Question 16

sampling

Answer 16

systematic + stratified

stratified site to sample characteristics then systematic across the river channel - 5 sample points per transect

Question 17

location choice

Answer 17

tributary of the river Wey. source Leith hill

close to school
-> easy to return to for repeat measurements

Question 18

risks

Answer 18

drowning
weather
slipping
Weils disease

Question 19

theory

Answer 19

Bradshaw model and the changes in river characteristics from source to mouth

Question 20

hypothesis

Answer 20

river velocity will increase downstream. channel width and depth will increase downstream

Question 21

velocity:

Answer 21

• measure out 5m of the channel lengthways
• dropped the cork just ahead of the person holding the tape and timed how long it took for it to move from one person to the other (5m)
• velocity = distance/time
• quantitative data
• stratified sampling
• variable reliability as cork could get stuck in current

Question 22

measuring width and depth:

Answer 22

• measure width of river at sample and recorded it
• divide width by four so we can sample sites at equal distance across river channel
• quantitative data
• stratified and systematic
• reliable but some innacuracy

Question 23

fieldsketch

Answer 23

• drew a fieldsketch at crossways farm to show nature of river and its size
• helps to identify why there might be anomalies in the data
• qualitative
• stratified as we picked the location
• subjective as it’s down to individual interpretation
• reliability varies depending on detail and if scale was used

Question 24

final conclusion

Answer 24

• channel depth and velocity increase as you move downstream
• width has an anomaly at site 2 due to human influence