The Water Cycle

Activities to try

1. 1

   Follow-and-perturb the water cycle landscape

   Why it works: The water cycle is a driven system — the sun powers evaporation and gravity pulls precipitation and runoff — not a self-moving diagram; plants are part of the cycle via transpiration, and human land-use changes genuinely reroute water.

   1. Ride a single labelled water droplet around the full loop: lifted off a sunlit sea as vapour, gathered into a cooling cloud, dropped as rain/precipitation, running across land as surface runoff, and returning to the sea.
   2. Adjust a sun-intensity control and observe evaporation speed up or slow; set the sun to zero and watch new evaporation stop and the cycle wind down (water already aloft still falls), so the sun is seen as the energy source.
   3. Watch the model's ribbons, which stand for invisible transpiration vapour, rising from vegetation as a contribution to the air's moisture (real water vapour cannot be seen).
   4. Swap a forested hillside for concrete/paving and observe two changes at once in the model: the ribbons representing transpiration vapour disappear, and rain soaks in much less and sheets off as runoff, raising the river below and making flooding more likely.
   5. State in words what drives each stage and how clearing or paving land reroutes the water.
2. 2

   Labelled cycle diagram with revealed drivers

   Why it works: The canonical representation of the cycle, with each stage named and its driver explicit, so vocabulary and sequence are secure as a reference.

   1. Label a water-cycle diagram including evaporation, condensation, precipitation, surface runoff and transpiration.
   2. Tap or lift a flap on each stage to reveal what drives it — e.g. 'sun heats water, liquid becomes vapour' at evaporation; a tree for transpiration.
   3. Toggle a human-impact layer and describe how land use alters the stages.
3. 3

   Mini water cycle: predict–observe–explain investigation

   Why it works: Evaporation is a change of state, not destruction: liquid water becomes invisible vapour that is still present, then condenses on cooling and falls back — the same water is recycled. The bowl is a simplified stand-in for the real sun-driven cycle.

   1. Put warm water in a clear bowl, cover tightly with cling film, and rest an ice cube on top.
   2. Before observing, PREDICT what happens to the water level and whether the evaporated water is 'gone', and write WHY.
   3. Watch droplets form under the chilled film and drip back; compare with your prediction.
   4. Explain where the water went and how it returned, using the words evaporation, condensation, precipitation and conservation.
   5. Note that this bowl is a model, not the real cycle: here the ice cube supplies the cooling and the warm water supplies the evaporation, standing in for the sun-driven atmosphere where the sun is the energy source and higher, colder air does the cooling.