4.2 The shape and form of your river
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   THE SHAPE AND FORM OF YOUR RIVER


The Murrumbidgee River as it flows out of Gigerline Gorge (near Canberra) to become a wider and slower river. Photograph: Luke Johnston.
Curriculum Alignment

ACT ELAs
3, 5, 14, 18, 19

NSW KLAs
Years K-6: Science and Technology, HSIE
Years 7-10: Agriculture, Science, Technics  
Years 11-12: Agriculture, Chemistry, Biology, Earth and Environmental Science, Society and Culture

QLD KLAs
SOSE, Science, Geography

SA ELs
Futures, Interdependence, Thinking

VELS
Science, Thinking Processes, Geography

Objectives
>Students will gain an understanding of how water flowing across the landscape shapes landforms and is shaped by flow pathways etc 
>Students will gain an understanding of the common terms used in this area of science 
>Students will apply this and other knowledge gained through this curriculum package to practical issues of catchment management
 

Duration
1 hour

Materials required
For Extension:
PVC stand pipe
PVC elbow joint
Large plastic box
Sand
Gravel
Large bucket
Rocks
River shape and form laboratory worksheet (see below)
For in-classroom adaptation:
Butcher’s paper
Glue
Old nature magazines


Background
River morphology describes the shapes of river channels and how they change over time. The morphology of a river channel is a function of a number of processes and environmental conditions, including the makeup of the bed and banks as well as the state of its vegetation, the rate of sediment transport through the channel and the rate of deposition on the floodplain, banks and bars.

When the junior Einstein said to his father that he had chosen for his doctoral thesis the topic of the mechanics of sediment movement and the dynamics of rivers, the senior Einstein, after prolonged silence, said: “Amazing! When I was at the point of choosing my topic I had exactly the same ideas. I never told anybody about this. However, after more detailed serious consideration it became clear to me that this was too difficult a subject. Hence, I opted for the simpler aspects of physics.”

Vocabulary
Glides
Reservoir silting
Delta formation
Meandering
Braiding
Floodplain
Pool
Riffles
Banks
Under cutting
Floodplain 
Platform
Terrace
Sandbar
Cascade 
Gorge
Oxbow

Lesson plan
Courtesy of Urbana Middle School, IL

1. Take the students to a section of their local river or stream (ideally the waterbody has to be flowing water, not virtually still like a lake for example). 

2. Give each student (or pair of for a larger group) one of the vocabulary words (see above) with its definition (see Glossary).

3. Ask the students to find in the area an example of their word.

4. Have them sketch their example, taking particular care in indicating how the water seems to be moving around their word/example.

5. If they have done other lessons from the Sustaining River Life package, ask them to explain the impacts or relevance of their word/example to aspects of the river such as water quality, macroinvertebrates, frogs, platypus, native fish, different vegetation communities, and where invasive plants or animals might most likely be found.

6. If time permits, allow students the opportunity to investigate their predictions.

7. Have students discuss the relative stability of various points they have looked at during this activity. Where do they predict changes will occur most quickly? Where would they build a house? What do the features they have noted say about the health of the river system in general?


Extension
Prepare the large plastic box as shown in the photograph.

Have the students place a PVC standpipe into the unthreaded end of the PVC elbow and make sure it is vertical.

Next, have students prop up the end without the pipes using scrap wood (for example).

Have the students connect up the inlet and outlet hoses as directed.

Students then fill the box partially full of alternating layers of sand, gravel, and rocks.

The students should make sure they fill the box so that the end opposite the pipes is filled higher than the end with them—this will create a ‘reservoir’ at the pipe end.


make sure the students
don't bury the standpipe.

Have the students carefully pour a small amount of water into the reservoir to fill up to the standpipe inlet level. This may take some time as the sand will absorb water. Take care not to disturb the sand and rock slope during filling.



Get the students to slowly start the flow of inlet water and watch how the river chooses its own path and shapes the land.

Older students can use the accompanying River shape and form laboratory worksheet (see below) to direct their work.


Classroom adaptation
Give each student one of the vocabulary words as either a homework assignment or in class and have them define it, and then go through nature magazines, or use the Internet, to find and cut out examples of their ‘word’.

Ask each student to present, explain and illustrate their ‘word’ to the class.

Draw a large map on butcher’s paper of a generic waterway.

Have students work together gluing their pictures on to the generic waterway.

Tape the completed map on the wall and ask each student to explain why they placed their picture where they did.
If students have done other Sustaining River Life lessons, ask them to discuss where they would expect to see good or compromised water quality, sensitive or tolerant insects, platypus, native fish, different vegetation communities, and where invasive plants or animals might be most likely to be found.