Making Catchments
Raindrops land on the ground and are soaked up by the soil. However in heavy rain, some water will run down slopes and wash soil away. In this experiment you will make different catchments to see how running water causes soil erosion.
Materials
2 milk or fruit cartons (2 litre size)
scissors
soil
mulch material (leaves, bark, sawdust, twigs, grass clippings etc)
margarine containers
watering can or "clouds" (from previous activity)
What to do
Step 1
With the pouring side face up, prepare the cartons by cutting out the section marked in the diagram.
Step 2
Fill the cartons with soil
Step 3
Place a layer of mulch material over the soil in one of the cartons
Step 4
Incline the two cartons to represent a slope. Place the margarine container at the base.
Results
Now you have two different catchments.
Sprinkle the same amount of water over each catchment and measure the time it takes for the water to flow into the container at the base.
Measure the amount of water in the containers.
Catchment A Catchment B
Water at start
Water at finsh
Time taken
Which catchment is more likely to have soil erosion problems?
Source: 'Our Land: Landcare activities for Upper Primary. National Soil Conservation Program 1989'