Information modified by Todd Koenig from Metro TIMES binder July 2009

Learning Outcomes:

  • Be able to discuss the importance of analysis stream flow
  • Recognize and practice the value of estimation in science
  • Be able to outline how stream flow measured, estimate the discharge of a small stream and understand the units of stream flow

Questions to explore/discuss/or journal:

Why is it important to measure the flow of a stream or river?

What factors are important to know about stream flow?

Brainstorm some ideas how to estimate the volume of water moving through a small section of stream. –What set of measurement tools will be needed for this task?

What units of measurement should we use to characterize stream flow?

Who would pay you to collect this data?

Why would people care about stream flow discharge?

Once a hydrologist has collected this data what could they do so they did not have to wade back into the stream every time someone wanted additional data? (Think drought or high levels of precipitation)

Exercise 1: Visual estimation of stream flow discharge. Work with one partner and estimate with your partner from the bank of the stream.

VISUAL average depth of the stream (in feet)
(in meters)
VISUAL width of the stream (in feet)
(in meters)
VISUAL velocity of the water (in feet per second)
(in meters per second)
Calculate your estimate of discharge here (SHOW YOUR WORK)
FLOW DISCHARGE= Depth x Width x Velocity
YOUR CALCULATED ESTIMATE
OF FLOW DISCHARGE

Exercise 2: Testing velocity with a ‘marker’. Test the velocity of the water using an orange. Organize this so the velocity is tested at a minimum of 3 locations the more you use the more accurate you will be. At a minimum test near both banks of the stream and in the center of the stream. The water must be deep enough to allow the orange to free float without contact with the bottom of the stream.

Explain below what you did to calculate the water velocity; SHOW YOUR CALCULATIONS
What is your average flow discharge for the stream?

Wrap up questions to journal/discuss:

How close is your tested measurement to your estimation of flow discharge?

Propose an explanation for the variations in the ‘test’ you just did:

What are your variables in this experiment?

What are your constants in this experiment?

Graph your depth vs. flow discharge for your Exercise 2 tests.