www.siemensstemday.com1Topic: Stream FormationReal-World Science Topics:• An exploration of how erosion and stream formation are related• An exploration of the speed of water flow changes the shape of a stream• An exploration of how erosion and sedimentation can affect the landscapeObjectiveStudents will gain an understanding of the value of using a scale model and the effect of water speed on erosion rate and stream formation.Materials Needed for Student ActivityMaterials Needed for Stream Table• 90 cm x 90 cm sheet of plywood• two 60-cm two-by-fours• two 90-cm two-by-fours• two 10-cm two-by-fours or four-by-fours• books, bricks, or additional lumber to prop the end of the stream table up (at least 20 cm high)• nails• hammer• drill with 3-cm bit• large bucket (at least 20 L in capacity)• hose• faucet to connect the hose to• bag of playground sand (at least 7 kg)• plastic sheet, at least 100 cm x 100 cm in size• large table• rocks ranging from 1 cm to 5 cm in diameter• small pieces of vegetationAdditional Materials Needed for Activity• Several sheets of paper• PencilGOING WITH THE FLOW(1 Hour)Addresses NGSS Level of Difficulty: 3 Grade Range: 3-5 OVERVIEWIn this activity, students use a stream table to model the processes of erosion and streambed formation. The students observe changes to the stream environment and make predictions about how these changeswill affect the stream. They then study and sketch the resulting streams.
2Teacher PreparationBuild the stream table by following the instructions provided below. This should be done prior to the day of the activity if possible.Fill the upper two-thirds of the stream table with sand to a depth of 5 cm. This lab can create a mess withwater and sand, so if possible perform the activity outdoors or in an area that is easy to clean up.About 15 minutes before class starts, turn the hose on at a slow, steady drip and allow the water to run intothe top of the sand. You may need to use tape or a clamp to hold the hose in place on the stream table. Instructions for making the stream tableDrill a 3-cm hole about 20 cm from one end of the plywood. This will be the drain.Nail the two-by-fours on the plywood so that they form a box on the plywood. Make sure the edges of the two-by-fours are touching tightly. See the diagram below. This will be the top of the stream table.Turn the table over so that the two-by-fours are on the bottom. Nail the 10-cm two-by-fours to the undersideof the table. They should be on the same side as the drain hole, but about 20-30 cm closer to the center ofthe table. See the diagram below. This will allow the drain hole to stick out over the end of the support table.GOING WITH THE FLOWTOP VIEWBOTTOM VIEWLEGSDRAIN HOLE
3Place the plastic sheet inside the “box” formed by the two-by-fours on the top of the table. Press the sheetinto the corners of the table, and make sure it is flat against the bottom of the table. Cut a hole in the plasticdirectly over the drain hole. The plastic will reduce the chances of water or sand leaking out of the stream