During a physical hydrology fieldwork enquiry, a group of students measured the velocity of water in a hillside runoff channel by releasing a non-toxic food dye tracer and timing how long it took the leading edge of the dye to travel a distance of 8 metres.
Suggest one reason why the runoff velocity data collected using this method might be inaccurate.
91 exam-style questions on OCR A GCSE Geography Fieldwork skills. Each one has a worked solution and a mark scheme showing where the marks go.