Rainfall Simulator

This demonstration uses a rainfall simulator to show how different types of land use - such as natural vegetation, agricultural land, and urban surfaces - affect water runoff and water quality. By comparing runoff and infiltration between surfaces, students learn how human activities influence water pollution and watershed health.

1. Set up a rainfall simulator containing different land-use models (such as natural grass, bare soil, agricultural fields, and paved surfaces).
2. Simulate rainfall across all models at the same intensity.
3. Collect the water that runs off each surface into separate containers.
4. Observe differences in water clarity, volume of runoff, and infiltration rates.
5. Compare and discuss how vegetation, soil cover, and impervious surfaces affect erosion, pollution, and water quality.

Rainfall Simulator Demonstration for School Education - Upper Trinity Regional Water District:

• Add fertilizer or soil to some plots to simulate nutrient pollution.
• Compare the effects of mulch, crop cover, or native grasses on runoff.
• Use different rainfall intensities to see how storm size impacts erosion and water quality.

• Ensure all electrical components of the simulator (if used) are kept away from water.
• Handle soil, fertilizers, or pollutants with gloves if included in the demonstration.
• Clean up spills promptly to prevent slipping hazards.

• Which type of land use produced the cleanest runoff water? (Natural vegetation absorbs water and filters pollutants best.)
• Which surface had the greatest amount of runoff? (Paved or impervious surfaces such as concrete.)
• How does vegetation reduce water pollution? (It slows runoff, allows infiltration, and filters out sediments and chemicals.)
• Why is it important to manage water runoff in urban areas? (To reduce flooding, prevent erosion, and improve water quality.)
• What conservation practices could improve water quality in agricultural land? (Cover crops, contour plowing, buffer strips, reduced fertilizer use.)