A group of students is conducting fieldwork to investigate changes in river discharge and velocity along a channel.
The students planned to use an impeller flowmeter to measure the water velocity at regular intervals across the channel. However, at their headwater site, the water in some sections was so shallow (less than 3 cm deep) that the impeller blades could not be fully submerged to spin.
State one way they could adapt their fieldwork technique to measure the velocity in these shallow sections.
