River Holford

• What is your physical geography research question?

  How is the River Holford a typical river according to the Bradshaw Theory?
• Give 2 reasons why your data collection location was suitable

  • Close enough to visit in a day and survey a range of sites
  • The river is not too fast so it is safe
• What theory underpins our investigation?

  The Bradshaw Theory

  Says as you are moving from the source to the mouth you will expect to see different features changing along the course of the river. We focus on velocity, width and depth, and sediment size and shape.
• Give 2 risks involved in your physical geography fieldwork.

  Rocky footpaths

  Cars
• Give 2 ways we prevented our risks from occurring

  Cars: Look both ways when crossing

  Rocky Footpaths: Walk carefully along, stay focused, mind footing
• Outline how we collected data on river velocity

  Sampling: Stratified (3 x 10m lengths)

  Description: Measured speed of a cork over a 10m length of river then calculated a mean

  Justification: See how the speed of the river changed. In a typical river, we would expect it to increase from source to mouth due to less energy wasted on erosion and less friction.

  Problem: Cork got caught on rocks

  Improvement: Measure an area with less rocks to catch on
• Outline how we collected data on bedload size and shape

  Sampling: Random (10 rocks)

  Description: Picked 10 rocks from the river bed at random closing our eyes, and measured the length using a ruler and the angularity by using the powers index.

  Justification: To see whether the size and angularity decreased due to attrition along the river's course.

  Limitation: Subjective, hard to measure bends with a ruler

  Improvement: Use calliper, Use the same person viewing the rocks
• Outline how we collected data on river width and depth

  Sampling: Systematic

  Method: We measured total width from bank to bank. We used a metre stick to record the depth at 10 intervals across the width of the river.

  Justification: Measures differences in depth and width between each course. We would expect both to increase due to processes of hydraulic action and abrasion.

  Limitation: Rocks got in way of depth

  Solution: Move rocks