EROSION IN A BOTTLE SCIENCE MODULE
PURPOSE
To understand what factors contribute to erosion and runoff in urban and agricultural settings by building a bottle runoff model.
MATERIALS
• (2) 9 Liter plastic soda bottles
• Sand
• Topsoil
• Mulch
• Sod
• Water
METHOD
Students will demonstrate the importance of mulch or vegetation in the reduction of erosion.
Three of the bottles are used to make soil trays.
One soil tray is left bare with only sand and topsoil.
On the second soil tray, a layer of mulch (either grass clippings or shredded newspaper) is applied to the soil
On the third soil tray, grass is grown on the soil.
All three trays will have 'rain' applied to them. The runoff from all three soil trays is observed and collected in a measuring cup. The amount of sedimentation in the runoff is then compared between the three surface manipulations.
DISCUSSION
- Which measuring cup has the most water?
- Was the mulch helpful in reducing the amount of runoff? Erosion?
- Was the topsoil washed away directly beneath the rain maker?
