Investigating river processes and management

Question 1

What is primary data?

Answer 1

Fieldwork data which you collect yourself or as part of a group

Question 2

What is secondary data, and what are two useful examples?

Answer 2

• Data that has been collected by someone else
• Important in giving background information and context for enquiry
• Past river flow data
• A flood risk map

Question 3

What is quantitative data?

Answer 3

• Involves numbers and counting
• Need equipment

Question 4

What is important to quantitative techniques?

Answer 4

Sample size

Question 5

What are the three types of sample size?

Answer 5

Random
- Where samples are chosen fairly randomly
Systematic
- Working to a system to collect data
Stratified
- Collecting a sample made up of different parts
- For example, deliberately selecting pebbles of different sizes from a point in the river so you include the whole range of pebble sizes found there

Question 6

What is qualitative data?

Answer 6

• Doesn’t involve numbers or counting
• Subjective, and involve the judgement of the person collecting
  Examples include:
• Written site descriptions
• Taking photographs
• Recording videos
• Field sketches

Question 7

What are different ways of presenting data?

Answer 7

Maps
- Used to show locations and patterns
- Makes it easier to compare patterns at locations

GIS and Photographs
- Used to show historic maps or sites which have been lost to erosion
- Helps to show how places have changed after being affected by storms

Tables of data
- Can be used to present raw data
- Useful to highlight patterns and trends
- Can help you identify anomalies

Graphs and charts
- Wide range available
- Can show data and patterns easily

Cross section graphs
- use contour lines to show depth of river

Question 8

What might affect the reliability of results

Answer 8

• Smaller sample sizes usually means lower quality data
• Frequency of data collection
• Type of sampling
• Equipment used
• Time of survey
• Location of survey
• Quality of secondary data

Question 9

What river was the fieldwork done in?

Answer 9

River Shuttle

Question 10

What equipment is used to find the river velocity?

Answer 10

• A float, such as a ping-pong ball
• Ranging poles
• Stopwatch
• Metre stick

Question 11

How do you find the river velocity?

Answer 11

• Measure the time taken for a float to go a specific distance- such as 5 or ten metres by using ranging poles
• Use a stopwatch to measure the time taken for the float to travel this distance
• Repeat in the middle, inside and outside of the river, then repeat 3-5 times on average

Question 12

What should the results of the river velocity show you?

Answer 12

• The outside bend should have a higher velocity, which explains why it erodes more due to hydraulic action

Question 13

What type of sampling is used for finding the river velocity?

Answer 13

Stratified sampling

Question 14

What equipment is used to find the river depth?

Answer 14

• Meter ruler
• Tape measure

Question 15

How do you find the river depth?

Answer 15

• Place a metre ruler into the river until it touches the riverbed
• Record the distance between the river bed and the surface of the water
• Repeat at regular intervals between the banks of the river
• Calculate an average

Question 16

What type of sampling is used to find the river depth?

Answer 16

Systematic sampling

Question 17

What equipment do you need to find the river width?

Answer 17

• Tape measure

Question 18

How do you find the river width?

Answer 18

• Extend a tape measure from the point where the dry river bank meets the water to the same point on the other side of the river

Question 19

What should the river width support?

Answer 19

• The Bradshaw model
• Channel width increases downstream

Question 20

What sampling is used to find the river width?

Answer 20

Random

Question 21

What equipment do you need to measure sediment size?

Answer 21

• Metre stick
• Ruler
• Powers angularity scale

Question 22

How do you measure sediment size?

Answer 22

• At each river site select 10 random stones by using a random method of collection- e.g put the metre stick into the water and remove whichever stone it touches
• Use a ruler to measure the length and the Powers Angularity scale to find the roundness

Question 23

What type of sampling is used to find sediment size?

Answer 23

Random

Question 24

What is our enquiry question?

Answer 24

• How and why do the channel characteristics of the River Shuttle change?
• How does these changing characteristics influence flood risk in Bexley?

Question 25

What are useful secondary sources for the fieldwork?

Answer 25

• Environment agency website
• Reports into flood risk in the area
• Property prices or insurance costs

Question 26

What secondary sources are useful for investigating how the characteristics of the river changed?

Answer 26

• Topographic and Geological maps
• Hydrological data
• Land use maps
• Soil maps
• Environmental reports

Question 27

How are topographic and geological maps useful?

Answer 27

• Provide details on the slope, elevation and physical features of the drainage basin
• Show the type of rocks and soils present, which influence water infiltration and runoff

Question 28

How is hydrological data useful?

Answer 28

• Can include records of river discharge and flow rates
• Rainfall data can give detailed records of precipitation patterns

Question 29

How are land use maps useful?

Answer 29

• Show how the land within the drainage basin is utilised (e.g agriculture, urban development, forests)

Question 30

How are soil maps useful?

Answer 30

• Provide information on soil types, structure, permeability and infiltration rates, which are useful for understanding runoff

Question 31

How are environmental reports useful?

Answer 31

lots of info on soil type, geology, vegetation levels, flood risk