Physical Geography fieldwork

In the Physical Geography exam you will be asked questions on a piece of Physical Geography fieldwork you have undertaken.  You should refer to the River Kym investigation.  Below is a summary of the investigation

Stage of investigation





Identify a suitable geographical question or hypothesis for investigation.


Does the discharge of the River Kym increase with distance from the source?

Suitable scale:

we had a minibus so could travel from site to site (only about 40km between source and mouth)

Readily researched:

used Bradshaw’s Model to see whether the river followed the expected pattern

Clearly defined:

-2 variables (discharge and distance)

-sets location of study area

-sets discharge as variable to be investigated

Clear geographical nature:

-spatial variation

-upper course of river carries large material –so low CSA & slow velocity

-due to attrition & abrasion, material gets smaller downstream & tributaries join river, so less vertical erosion, more lateral erosion & more energy = higher CSA & faster velocity

-CSA x Velocity = Discharge

-discharge increases downstream

Based upon geographical theories:

Bradshaw’s Model, showing expected trends of rivers

Clear aim:

to measure various points along the course of the river and see whether discharge increases downstream

  • The question has clearly defined terms and sets out the parameters of the investigation
  • However doesn’t state how discharge will be measured
  • The first attempt at a question was too vague and broad – didn’t give a specific factor for investigation in the study
  • Also makes investigation too complex because Bradshaw’s Model consists of so many elements – would all have to be investigated to answer question accurately

Develop a plan and strategy for conducting the investigation.



Type: point sample – 5 sites

Method: pragmatic sampling – accessible from the road, ideally would have been systematic to have more representative results but can’t access private land


Type: point

Method: pragmatic)


Type: point sample

Method: systematic


Type: linear sample

Method: systematic

Primary data:




-photos/field sketches

Secondary data:

-map of river

-distance from source (explorer GIS app)

-Bradshaw’s Model

-statistical test (Spearman Rank Correlation Coefficient)

-Google Earth


-tape measure

-2 ranging poles

-1 or 2 metre rules (plastic)

-2 pairs of waders

-clipboards and pens

-data collection sheet

-dog biscuits


Risk Assessment:

-drowning – take care in water and don’t go to very deep areas

-illness – wear suitable clothing

-losing equipment – take spares

-flooding – assess safety of each site, skip if too dangerous

-river debris – take care in river

-slipping over – suitable footwear, e.g. waders

-accident on minibus – licenced driver, wear seatbelts


  • RIVER – point because we went to 5 individual sites and pragmatic because some sites would have been inaccessible if we had done systematic
  • DEPTH – systematic point because we took a sample every 10th of the width across the river
  • VELOCITY – systematic linear in middle of river, we measured the time it took for a dog biscuit to travel from A to B over a few metres
  • Considered most appropriate and practical for the necessary data and sites

Primary Data:

  • Used so accurate results could be taken and used to create a valid conclusion

Secondary Data:

  • Used to be able to locate sites and plan the investigation before going to each site and identifying suitability


  • Most accessible for the investigation
  • Would have preferred to use more advanced equipment, measuring to a higher resolution and reduce risk of human error, e.g. Stream flow meter (didn’t work in pilot study so couldn’t use it)

Risk Assessment:

  • Carried out to ensure all issues accounted for and that, in conducting the investigation, no risks presented to recordings
  • Calculated through assigning each risk and its severity out of 5 and calculating overall risk out of 25 for each element to assess safety


  • RIVER – 5 sites = enough data in the time available, but has to be accessible & close to  a road (due to time) so pragmatic is more appropriate
  • DEPTH – every 10th is easy to calculate and gives a good representation of the river
  • VELOCITY – 3 to get average and good representation of river
  • Sampling methods chosen as they seemed most appropriate and realistic for collecting data for the investigation

Primary data:

  • Width & depth to work out CSA, then CSA x velocity = discharge
  • Photos or field sketches as a point of reference to remember characteristics of each site
  • Needed this data to calculate actual discharge values at each site
  • By using primary data, I controlled what conditions the results were recorded in and, to the best of my ability, controlled the method to reduce human error


  • Most available and practical for the investigation
  • However would’ve preferred to use stream flow meter instead of dog biscuits to measure velocity – may have reduced accuracy of velocity results thus influencing discharge calculations

Risk Assessment/Plan:

  • Essential to plan investigation to ensure that it’s achievable in the 6-hour timeframe
  • Conducted risk assessment to ensure safety for all members of the group – if it had been deemed unsafe, an alternate method or location would have been chosen

River Sampling:


-went to 5 sites, evenly spaced out as possible, which gave a picture/representation of whole river

-pragmatic sampling meant we could avoid dangerous situations & go to accessible parts of the river in the time we had to get the work done


-near to bridges, which affects results, so would’ve been better if we’d walked about 20m down the river away from bridge to avoid distortion of results

-however these bridges are there so measuring next to them is a true representation of the river

-potentially go to more sites

Depth Sampling:


-taking a reading at every 10th across river made it easy to work out where to read (just divide width by 10)


-width of river increases downstream but we still took 9 readings for the depth at each site, so it wasn’t a true representation of the river the whole way down – more reliable upstream

-we should have measured every Xcm across the width to be consistent

Velocity Sampling:


-3 readings was a good sample size and we could take a median, which gets rid of anomalies well


-we only took the velocity at the surface of the water, we didn’t test the main current of the river so wasn’t a true representation



-equipment enabled collection of all necessary readings


-dog biscuits – results influenced by flow in the channel as well as increased issue of response time, so served its purpose but more accurate equipment would have been preferable

Risk Assessment:

-successfully identified a broad spectrum of potential risks and put in place ways of preventing injury & ensuring safety of group throughout investigation

Collect and record data appropriate to the geographical question or hypothesis.


5 sites chosen pragmatically along the river – selected accessible sites that were as representative as possible whilst safe & accessible


tape measure held taut above water, nearest cm, at least 3 people required – reliability improved by following set method


9 readings taken, each 1/10 across width of river, plastic metre rule used, nearest cm, at least 3 people required – create accurate and comparable profiles & make CSA measurements more reliable


3readings in total across river, dog biscuits, ranging poles, tape measure, stopwatch, 4 people required

5m – distance should reduce risk of human error as it’s long enough to time more precisely

  • WIDTH – tape measure (0 on left side of river), measure slightly above surface of the water, make sure it’s pulled tight, make sure it’s in cm
  • DEPTH – ruler, divide width by 10, take a reading of depth at each tenth of width, 9 readings in total
  • VELOCITY – place 2 ranging poles in river, one downstream from the other, measure distance between them using tape measure, drop dog biscuit at first ranging pole and measure time taken to reach 2nd ranging pole using stopwatch, repeat 3 times


  • Sites all accessible & data collected
  • Some sites too small to measure along 5m for velocity – had to reduce to 3m, but didn’t affect results
  • Some points of river above normal levels – extra care taken


  • Changes made to collection methods down to conditions on the day
  • Techniques used chosen as simple to carry out & didn’t require expensive equipment
  • Dog biscuit technique used as it was simple & could easily be repeated. Also enabled multiple groups to carry out readings simultaneously along each site as didn’t have to wait for one piece of more advanced equipment

Collecting width:


-measuring tape held just above surface of water so current didn’t take it away

-tape measure easy to use

-width pretty accurate – there was room for error with the discharge


-reeds/bulrushes made it difficult to measure where the river bank actually is or where the river really starts

Collecting depth:


-ruler was easy to use & read, and was rigid so stayed in place, which meant accurate results could be obtained


-some parts of the river were too deep to walk into, which made it more difficult to take the readings where they were meant to be taken

Collecting velocity:


-dog biscuits were easy to see, so we could easily tell when the dog biscuits reached the 2nd ranging pole

-4 people working effectively made it easier to time, etc.

-adaptable method (could change distance between ranging poles depending on the site without affecting results)

-easy to do the maths afterwards (we originally measured the time taken and then afterwards divided the average time by the metres it was measured over)


-dropping the dog biscuits next to the pole & ourselves affected the time slightly as it floated around the same spot for a short while before starting to move downstream

-to avoid this, we should’ve stood further to the side of the ranging pole, out of the flow of the river and dropped the dog biscuit the other side

-there was a delay between the person in the river saying stop and the person with the stopwatch actually stopping the time (although this didn’t affect results because we got rid of anomalies), would’ve been better if person in the river saying stop just had the stopwatch instead

-groups further upstream were moving about which slightly affected the flow of the river

-wind resistance on the dog biscuits as some areas were slightly more open, which delayed the dog biscuits

-could’ve used an orange or something else heavier instead that sits in the water a bit more and isn’t so easily affected by wind resistance

Present the data collected in appropriate forms.

Techniques used:

-CSA shown at each site to show visual distinction between cross-profile of each of the 5 sites

-discharge ranked & colour coded – CSA coloured in darkest blue if highest discharge, lightest blue if lowest discharge

-all shown on map of river where each site was

-choropleth using same colour clearly shows order of discharge ranking

-colour blue stands out

-on map to show spatial variation

-all very visual & easy to understand

-shows how river changes downstream

Gave clear visual indication of changes in data and also showed a relationship between discharge and channel shape as well as distance downstream


-ranked choropleth was very useful in visually representing data & in ranking discharge values – clearer than using actual values as very concentrated


-scale used made first few sites’ cross-profiles very small – made it hard to plot accurately

-therefore reduced accuracy as a form of data presentation

Analyse and interpret the data.

This includes both written and visual techniques which are geographical and statistical.

DATA PRESENTATION: see general pattern of discharge increasing downstream as choropleth gets darker further downstream, however not in perfect order

GRAPH: scatter graph hand drawn, shows positive correlation between distance from source and discharge, line of best fit used to identify trend in data & find anomalies, compared against Bradshaw’s Model – shows it follows it generally with a few anomalies, potentially at sites 6, 8 and 9

STATISTICAL TEST: used Spearman Rank Correlation Coefficient and got a result of 0.9 (strong positive correlation), scored 99% on significance test so is a valid result


-CSA gets bigger downstream due to tributaries joining, adding more water – leads to lateral erosion due to increased hydraulic action

-depth doesn’t change much as rocks get smaller so can’t abrade & vertically erode as much

-less friction downstream so river is faster, combined with bigger CSA = higher discharge

Reasons for anomalies:

  • Bridges at some sites
  • Straightening & dredging of river, meaning river flows faster
  • Drainage ditches from farmers’ fields

Why scatter graph?

Gave clear visual representation whilst incorporating numerical values – more useful in drawing conclusions

Why Spearman’s rank?

Gave quantifiable values as to correlation of 0.9 – strong positive correlation. This enabled me to statistically accept my hypothesis to be true

Scatter graph showed data clearly, however it was harder to find an exact line of best fit due to some extreme anomalies.

Spearman’s rank gave clear result.

Present a summary of the findings and an evaluation of the investigation.


The discharge of the river does increase with distance from the source as a general pattern; however there are a few anomalies. After performing a statistical test – the Spearman Rank Correlation Coefficient – it was made clear that the correlation between the discharge of the river and the distance from the source had a strong positive correlation of 0.9 (which scored 99% on the significance test, so is a valid result). The anomaly at site 8 is most probably due to straightening of the channel and dredging of the river which have taken place there, meaning that the river will have been flowing faster than usual here. The anomaly at site 6 is due to the fact that we took our readings before a bridge, which slows the river down slightly. Despite the anomalies, the general trend of my results follows the trend expected from Bradshaw’s Model. If the investigation was to be repeated, I would use more precise equipment and a systematic sampling of sites to reduce the potential of changes in the river being missed. I would prefer to use a stream flow meter, as using dog biscuits to measure velocity was a very limited method.

Suitable question:

Yes, appropriate scale & defined parameters of investigation

Plan and strategy:

Clear plan that was successful & coped with any issues faced on the day to ensure all results were collected

Record data:

Data clearly recorded & enabled clear synthesis of results – meant accurate and valid conclusions could be drawn

Data presentation:

Using location and colour to visualise trends in the river

Analyse and interpret data:

Data analysis was very useful and clearly proved the hypothesis through the graph and statistical test

Summary and evaluation:

Summary gives clear numerical answer to question posed

  • Conclusions from this investigation use a reliable method to collect data
  • Tried where possible to reduce risk of human/systematic error – could put at risk accuracy of data recorded through poor method
  • However overall collection was accurate & helped to form valid conclusions working with numerical & visual analysis and presentation of data


Timings worked successfully – plenty of time at each site


Locations of sites worked well for investigation


Some issues in accessing river due to steep banks, but with ranging poles it was safe and access was possible

Human Error:

Potentially occurred with different groups taking some site readings due to size of sites but still followed method to hopefully avoid any human error

Equipment and Methodology:

Both worked well to gather required results, however would’ve preferred to use stream flow meter to measure velocity in more accurate way