This podcast is part of the series: Planet H2O
McWane Science Center
Seventy percent (70%) of the Earth’s surface is covered with water and when viewed from space, our planet appears blue with a plentiful supply of water. However, clean, fresh water for drinking and irrigation is a scarce and valuable commodity in many parts of the world. Even though water is abundant on our planet, only a very small percentage can be used by humans and other organisms.
This activity demonstrates the sources of water on our planet. Reduce Earth’s water supply to 2 liters and then use common household items to represent the distribution of water on our planet. More than half a gallon is found in the oceans, inland seas, and salt lakes – water that is too salty to use. At the end of the activity, you will see that only about 1 teaspoon of our original 2 liters is readily available for human use – water that is found in rivers, lakes, streams, and underground aquifers.