Physical fieldwork - Aim, Location, Methods, Sampling

I miss carding mill valley

What is your geographical enquiry?

How do the river’s characteristics change with distance downstream?

What do you aim to investigate?

How does velocity change downstream, how does bedload shape and size change direction, how does cross section change downstream?

What does theory suggest about the average bedload shape and size and why?

Bedload becomes smaller and more rounded along its course due to attrition, the further the bedload travels, the more time attrition has

What does theory suggest about the average velocity and why?

Velocity gets slower along its course as the gradient gets steeper so the river loses energy

What does theory suggest about the average channel width and depth and why?

The channel width and depth should widen and deepen as you move downstream due to lateral and vertical erosion

Where is your location?

Carding Mill Valley is West to the West Midlands and is one mile north-west off Church Stretton. It is a valley that lies in Long Mynd and in the county of Shropshire

What makes your site accessible?

It’s not far to travel to so data collection can be done within a day, making it more efficient

What makes your site safe?

The stream depth is safe to work in and the velocity isn’t too fast so it’s possible for us to collect the data needed for the conclusion

Risk assessment of trips/slips/falls?

Low risk → Be observant of surroundings, suitable footwear with good grip

Risk assessment of drowning in stream?

Low risk → Working in a group in case of difficulty

Risk assessment of hypothermia or sunburn?

Low risk → Hypothermia: have suitable clothing, specifically warm

Sunburn: wear suncream, take shade, keep yourself hydrated

Risk assessment for getting separated from the group?

Low risk→ Headcounts at frequent intervals, ensure you’re always working in groups

Risk assessment for contaminated river water?

Low risk → Don’t drink river water, wash hands or hand sanitize before eating

What is your first step for finding bedload size and shape and why?

Randomly select 10 rocks from specific intervals to prevent bias and increase accuracy as you pick the rocks

What is your second step for finding bedload size and shape and why?

Use the calliper to measure the rocks as it gives accurate measurements

What is the final step for finding bedload size and shape and why?

Use the same 10 rocks and assess them using the Powers Stone Shape Chart so there’s no bias and it has the same description

How does the bedload size and shape methodology help investigate your hypothesis?

It gives you an accurate size of the rocks so you can see how they change downstream and you can see how the shape of the rocks changes downstream

What sampling does the bedload size and shape methodology use and why?

Systematic and random sampling which makes the data collected fair and unbiased

What is the first step for measuring cross section and why?

Using a tape measure, measure from bankful and hold it taut to ensure an accurate and consistent width measurement

What is the last step for measuring cross section and why?

Divide the length by 10 and at each interval, measure the depth using a metre stick as the systematic sampling ensures the data is evenly spread and avoids bias

How does the measuring cross section methodology help investigate your hypothesis?

It helps to investigate whether the channel width changes downstream and shows how channel depth and shape changes downstream

What is the first step for measuring velocity and why?

Measure 5m from upstream towards downstream using a tape measure and place a dog biscuit so that there’s a control variable

What is the second step for measuring velocity and why?

Out loud, count how long it takes for the biscuit to travel 5m as timing the float provides a direct measure of surface velocity

What is the third step for measuring velocity and why?

Repeat three times to increase accuracy

What is the fourth step of measuring velocity and why?

Calculate the average time by calculating the mean to ensure a fair test and reduce the impacts of anomalies

What is the final step of measuring velocity?

Calculate velocity by using distance divided by average time