Fieldwork

• Systematic sampling is collecting data in an ordered or regular way, e.g every 5 metres or every fifth person.
• Why a river channel investigation may not achieve the aim given

  • Data inaccurate 
  • Insufficient data collected 
  • Inaccurate data analysis 
  • Human errors in data recording 
  • Aim not practical 
  • Unsuitable sites selected 
• • Examples of an aim would be:
  • An investigation into how a river's cross-profile changes downstream
  • An investigation into changes in discharge with distance downstream
• Examples of a hypothesis would be:

  • The width and depth of River Y will increase with distance downstream
  • The discharge of River Y increases with the distance downstream
• • Random the use of random sampling means that all sites have an equal chance of being selected which eliminates bias
• • Random the use of random sampling means that all sites have an equal chance of being selected which eliminates bias
• • Random the use of random sampling means that all sites have an equal chance of being selected which eliminates bias
• GPS can record site location to give an accurate location using latitude and longitude
• To select the river sites sampling (stratified, random and systematic) should be used to reduce bias
• Systematic sampling method to use in a river chanel investigation

  
  

  • Measuring at regular intervals 
  • Ensures that no parts of the river are missed 
  • And it reduces bias 
• Random sampling method to use in a river chanel investigation


  • Using a random number generator
  • All sites have an equal chance of being selected
  • NO bias.
• Equipment needed to measure river: 1) Meter tape, 2) Meter ruler, 3) Clipboard 4) Pencil 5) Camera 6) Float/flowmeter 7) Stopwatch
• • Float or flowmeter for measuring velocity
• meter tape to measure the river width and for marking out distance downstream for velocity measurements
• • Risks associated specifically with river fieldwork may include:
  • Weather conditions
  • Slippery rocks
  • Polluted water
  • Working in an unfamiliar place
  • Misuse of equipment