Paper 2- Section C- Rural Investigation

Question 1

What is random sampling?

Answer 1

sites or samples picked at random to reduce bias.

Question 2

What is systematic sampling?

Answer 2

sites are selected at set intervals to ensure full and even coverage of the area is being studied

Question 3

What is strategic sampling?

Answer 3

sites are deliberately chosen to ensure appropriate coverage for enquiry

Question 4

What sampling technique did we use to select our sites, and why?

Answer 4

we used stratefied sampling to ensure we could and would cover all sites in not too long of a time period, to ensure a good sample range, and to make sure it was safe. It was also convenient - access to car park, cafe and toilets.

Question 5

Describe why site 1 (upper course) was selected

Answer 5

Selected as it was near the source so we can expect the channel to be narrow, shallow, slow, with lots of vegetation, and little vegetation, as well as steep land that could cause flooding.

Question 6

Describe why site 2 (middle course) was selected

Answer 6

Selected as it was near the ford and further downstream. We can expect a faster, wider channel with more rounded rocks and a shallower gradient. It was affected by the ford - blockages and debris from the footpath and humans blocking the river. More surface run off from car park.

Question 7

Describe why site 3 (lower course) was selected

Answer 7

Selected as it is closest to the car park. We can expect the widest, deepest channel with smoother rocks and a fast velocity. Lower, and more urbanisation (housing, car park) may lead to low permeability, and therefore more flooding.

Question 8

What secondary sources did we use?

Answer 8

OS maps, geology maps, news reports/articles

Question 9

What did we learn from OS maps (secondary source)

Answer 9

contour lines are close together shows steep valley sides, shows man-made surfaces, tributaries

Question 10

What did we learn from geology maps (secondary source)

Answer 10

we can see lots of precambrian sedimentary sandstone, which has a high porosity and permeability so more water is stored, which decreases flood risk.

Question 11

What were our sub questions?

Answer 11

How do river and valley characteristics vary along the Ashbrooke stream?
Do width and depth increase as you move downstream?
Does velocity increase or decrease from source to mouth?
Does higher discharge increase flood risk?
Which places are most at risk of flooding along the river Severn?

Question 12

What was the name of the stream we investigated?

Answer 12

Ashbrooke stream

Question 13

What did we learn from articles?

Answer 13

• heather managed by burning it removes vegetation which reduces interception
• 3000 sheep farmed there causes overgrazing, so more ground is exposed so interception is reduced
• stream flows into Church Stretton, a built up town with many houses and roads: impermeable surfaces increase surface run off
• tourism increases flood risk bc more infrastructure is built

Question 14

What method did we use to collect data on velocity and how could we improve it?

Answer 14

pingpong ball between the poles (10m apart), repeat 5 times
should do many more repeats

Question 15

What method did we use to collect data on width?

Answer 15

measuring tape across river surface, and bank to bank

Question 16

What method did we use to collect data on bedload, and how could we improve it?

Answer 16

sediment analysis - we measured radius, and put them into “roundness classes”
we should randomly select rocks, and maybe ask multiple people to classify them (roundess), as it is basically an opinion and therefore could be subjective and biused.

Question 17

What method did we use to measure the depth and how could we improve it?

Answer 17

every 10cm, use a ruler to measure depth across stream
make sure you are at eye level with ruler

Question 18

What did we find out about discharge from sites 1-3?

Answer 18

• it increased from site 1-3, because cross sectional area (width and depth) increased, which allowed more water to flow. The area increased because more tributaries joined the river, so the water had more power to erode.

Question 19

What happened to gradient from sites 1-3?

Answer 19

It decreased (shallower) as the river moved from higher, to lower, flatter land. This matches Bradshaw’s model

Question 20

What happened to bed load as we move downstream?

Answer 20

It became rounder and decreased in size. This is because more tributaries joined the river, so it had more power to erode so abrasion and attrition could occur, breaking down and smoothing the rocks. This matched Bradshaw’s model.

Question 21

What happened to velocity (our anomaly) as we moved downstream?

Answer 21

It didn’t increase overall. This was the only characteristic that didn’t match Bradshaw’s model.

Question 22

What was our enquiry question?

Answer 22

How do different drainage basin and river channel characteristics influence flood risk for people and property along the River Severn?