Stream Gaging Field Trip
The following is your fieldtrip pre-trip assignment. Complete questions 1, 2, and 3. Use a
separate sheet of paper. If you need to use a geological dictionary for some words, there
is one in the library. This assignment should take you 1 hour or more so donít wait until
the morning of the trip to start. Read the second set of questions so you will know what to
look for during the field trip.
1. Read/reread the section in a text on streams; write the page numbers here for
what you have read: _____________________.
2. Define the following words. We should use all of the following vocabulary on the
trip; if not then ask:
2.2. cross section
2.4. flood plain
2.6. graph: what is one and how do you make one?
2.7. intermittent stream
2.9. riparian zone
2.12. stream channel
2.13. stream gaging
2.14. stream loads; list and explain all three of these
2.15. stream system
2.16. stream terrace
2.17. stream valley
2.19. Udden Wentworth scale a.k.a Wentworth scale: list all the names
2.21. wetted perimeter
3. You will be taking data to use to calculate the discharge of a stream. The only tools
you will be using will be a tape measure, a cork, and a watch with a second hand or stop
watch functions. You will calculate the discharge in cubic centimeters per second (cm3/s).
How do you do this? Beware of the text book, it is very misleading and will get you into
trouble. See me or Rick to make sure you understand what you will be doing!
The pre-trip assignment is a required part of the field trip report and must be included; however,
your rough field trip notes should not to be submitted.
During the trip: you will need to take data to use in answering the questions on the back of this
paper. Read the questions before we leave and ask about parts that you do not understand
before the trip ! ! !
Following are the questions to be completed on the field trip and written up afterwards. Type all
answers, put them in the order given, include your pre-trip at the end, and place it all in a thee-hole
paper folder. You will need to neatly redraw any required sketches and place them in the proper
1. Submit a diary of all stops and events of the day. Include non geological events as well
as your scientific observations. (50 points; note that this question is competitive and only
the most complete answer will get all 50 points.)
2. Approximately, how wide was the riparian zone at each stop? Why did the riparian
vegetation and wildlife change at each stop? This may be answered by thinking of
available water and temperatures during the entire year. Sketches of each stop are
required. (20 points)
3. Were there any steam loads and if so what were the sizes of the particles? Remember,
loads are moving. Be sure to check for silt and clay sizes. (5 points)
4. Measure the time it takes your cork to travel 200 cm at the center and the sides of the
stream for each stop; your measurements must be identical for at least three runs to be
considered valid: repeat measurements until you have three identical times. Then calculate
the velocity in centimeters per second (cm/s) for each location. Average the velocities for
each stop. For stops without water, just state there was no water. Show your calculations!
5. Measure the depth of each stream at several points in a straight line from the shore to
the opposite shore. If there was no water just state that fact. Use graph paper to make
an accurate cross section of the stream for each stop; remember that depths will be
plotted downward from the top of the stream. Then determine the area of the stream from
the graph by counting the squares and multiplying by the area value for each square. (20 points)
6. What was the discharge in cubic centimeters per second (cm3/s) at each of the stops?
This can be calculated by multiplying the area of the stream by the average velocity at that location.
If there is no water at a location, state the discharge is zero. Remember to give the answer
with the correct number of significant figures. See me or a tutor if you have any problems with
the arithmetic. Show your work. (20 points)
7. All stops are along the same stream system; e.g. the water from the highest location
should run through all other locations. List the stops from highest location to lowest location,
then list the discharge for each location next to the stop number and name. (5 points)
8. The discharge will not be identical for all stops unless something very unusual happens.
Since discharge is the volume of water flowing in the stream at the point measured, explain
where the water may be coming from and/or going to. This is your think question so think
about it and donít waste your time trying to find the answer on the net or from the book. (40 points)
9. Pre trip assignment with signature and all questions answered. (20 points)