channel, deep verses shallow water, gravel substrate verses sandy substrate) Evaluate: For grades 8 - 9: Calculate the velocity of the stream if the orange floats at a rate of 100 feet in 1.5 minutes. Calculate the flow rate of a muddy bottom stream if the average width is 5.5 ft and average depth is 17 inches and the orange floats at a rate of 67 ft in 2.4 minutes. What does the flow tell you about the watershed? What unit is flow measured in? When velocity increases in a stream, what happens? What factors contribute to an increase in water flow? For grades 9 - 12: If the average depth of the stream is 4 ft and width is 7.5 ft and it took the orange 10 seconds to travel the 10-foot length of the stream, what is the volume? If two streams drain equal sized and comparable watersheds, and one watershed is forested while the other is urban, which will have a greater discharge of water? Why? Extension: In the last step, the students compared their results and hypothesized what caused them to be different. As an extension, have the students investigate streams in their community noting changes that might have been made to them and how it has affected stream flow. Also have the students look at what are some of the consequences that occur as a result of those changes to the stream. Have students convert the various measurements to metric. Adapted from Georgia Adopt-A-Stream Educator’s Guide Based on Georgia Adopt-A-Stream Visual Stream Survey procedures. CALCULATING STREAM FLOW Flow = Area X Speed X Coefficient CALCULATE AREA Area = depth x width It is advisable to take multiple depth and width measurements always start at the waters edge with a first measurement of zero all data should be recorded in feet, with inches replaced by increments of 10 1. 2. 3. 4. 5. 6. 7. 8. sum depth measurements 0 ft
channel, deep verses shallow water, gravel substrate verses sandy substrate) Evaluate: For grades 8 - 9: Calculate the velocity of the stream if the orange floats at a rate of 100 feet in 1.5 minutes. Calculate the flow rate of a muddy bottom stream if the average width is 5.5 ft and average depth is 17 inches and the orange floats at a rate of 67 ft in 2.4 minutes. What does the flow tell you about the watershed? What unit is flow measured in? When velocity increases in a stream, what happens? What factors contribute to an increase in water flow? For grades 9 - 12: If the average depth of the stream is 4 ft and width is 7.5 ft and it took the orange 10 seconds to travel the 10-foot length of the stream, what is the volume? If two streams drain equal sized and comparable watersheds, and one watershed is forested while the other is urban, which will have a greater discharge of water? Why? Extension: In the last step, the students compared their results and hypothesized what caused them to be different. As an extension, have the students investigate streams in their community noting changes that might have been made to them and how it has affected stream flow. Also have the students look at what are some of the consequences that occur as a result of those changes to the stream. Have students convert the various measurements to metric. Adapted from Georgia Adopt-A-Stream Educator’s Guide Based on Georgia Adopt-A-Stream Visual Stream Survey procedures. CALCULATING STREAM FLOW Flow = Area X Speed X Coefficient CALCULATE AREA Area = depth x width It is advisable to take multiple depth and width measurements always start at the waters edge with a first measurement of zero all data should be recorded in feet, with inches replaced by increments of 10 depth measurements 1. 2. 3. 4. 5. 6. 7. 8. sum 0 ft
Flow-and-cross-section-lessons-1.docx