Name: _______________________
Class Period: ___________
Relationship of Transported Particle Size to
Water Velocity
Purpose: In this exercise you will gain practice interpreting a chart dealing with how
fast water must be moving in order to be able to transport different sized rock
material.
Procedure: Complete the chart below and answer the two questions about river X
with data from page 6 of the ESRT. When you are finished with that you may
answer the discussion questions on the back
Sediment Type
Sediment Diameter
Velocity Required to Transport
Boulder
Cobble
Pebble
Sand
River X
 At points B and C the river is moving at
1.1 cm/s.
 At points D and A the river is has a
velocity of 0.1 cm/s.
1) Which of the sediments would be Eroded
(transported or moved) at points B and C?
2) Which of the sediments would be deposited
(Can no longer move) at points D and A
Discussion Questions: Answer all questions on
this page. Use the Velocity vs. Transported
Particle Size graph on page 6 of your ESRT. Use correct units. (cm for diameter
and cm/s for velocity)
1) Name the particles (sediments) that will be carried by water at the following
velocities:
a- 500 cm/sec ____________________________________________________
b- 100 cm/sec ____________________________________________________
c- 200 cm/sec ____________________________________________________
d- 50 cm/sec _____________________________________________________
2) Name the particle(s) that will be deposited if a stream moving at 700 cm/sec
suddenly decreases in velocity to 225 cm/sec?
_________________________________________________________________
3) State the water velocity necessary to maintain the transport of the following sized
particles.
0.1 cm particle diameter: __________________________________________
25.6 cm particle diameter: _________________________________________
0.001 cm particle diameter: ________________________________________
10 cm particle diameter: ___________________________________________
4) As soon as water velocity decreases even slightly, what occurs?
______________________________________________________________
5) Name the particle(s) that cannot be transported by a stream moving at 150
cm/sec.
______________________________________________________________
6) State the range of particle sizes for a "cobble".
__________________________________________________________
7) At approximately what speed will the stream no longer be able to transport
pebbles?
__________________________________________________________________________________________