Unit 2

Question 1

What’s the aim of the investigation?

Answer 1

To investigate how the characteristics of the River Ogmore varied from source to mouth

Question 2

What were the objectives/hypotheses for velocity, clast size and shape, width and depth?

Answer 2

Closer to the mouth, the higher the velocity
Clast size decreases & becomes smoother and rounder downstream
Width increases along the river course
Depth increases along the river course

Question 3

What were the advantages of the location used?

Answer 3

• Variety of rural and urban areas
• Changing geology (clay, alluvium, peaty soils)
• Villages and roads
• Easily accessible
• Sights judged to be safe after risk assessment
• Trained guides to minimise dangers
• Near car parks if any accidents occurred

Question 4

What type of data collection was used for measuring the width, how was the data collected (method) and what were the limitations?

Answer 4

Stratified sampling (upper/middle/lower)

• Tape measure across river
• Bank to bank (where water touched)
• Difficult to locate the exact waters edge

Question 5

What type of data collection was used for measuring the depth, how was the data collected (method) and what were the limitations?

Answer 5

Systematic sampling

• Width divided by 6 to give 5 points
• Metre stick lowered into water at each point
• Where water reached was recorded
• Conditions meant water splashed around - hard to read

Question 6

What type of data collection was used for measuring the velocity, how was the data collected (method) and what were the limitations?

Answer 6

Stratified sampling

• Points picked at either side of river (near banks) and one in middle
• Hydroprop flow metre lowered into water at each point
• Stopwatch timed how long it took for the impeller to reach the end of the spindle
• Picked points by eyee
• Large bedload got in the way
• Delay in recording time

Question 7

What type of data collection was used for measuring the clast size and shape, how was the data collected (method) and what were the limitations?

Answer 7

Random/stratified sampling

• 10 pieces selected and measured
• Average size taken down
• Each bedload was compared to Power’s Scale of Roundness
• Bedload generally taken from one area
• Not specific length chosen to measure (longest points or width etc)

Question 8

Name each risk and how it was prevented

Answer 8

Drowning in deep water - check depth, not above knee height
Slips/trips/falls- appropriate footwear, watch wear you’re walking
Low body temp- suitable clothing and lots of layers
Traffic - look both ways before crossing road
Infections from water - wash hands and don’t drink water

Question 9

What were the velocity measurements for site 1 and site 6?

Answer 9

1: 1.3
6: 0.99

Question 10

What was the average clast size at site 1 and site 6?

Answer 10

1: 189mm
6: 37.6mm

Question 11

What was the clast shape at site 1 and site 6?

Answer 11

1: angular
6: well rounded

Question 12

What was the width at site 1 and site 6?

Answer 12

1: 1.3m
6: 23.7m

Question 13

What was the depth at site 1 and site 6?

Answer 13

1: 0.17m
6: 0.81m