vailability Fact No. 1 Nearly three-fourths of the earths surface is covered in water. However, only 3% of that water is drinkable. Two-thirds of that 3% is restricted to glacial ice, so only 1% of the total amount of water on earth is readily useable in bodies of fresh water, aquifers and springs. Fact No. 2 All the water we now have is all we ever had and all we ever will have. It is a finite resource. Click here www.iwr.msu.edu/edmodule/water/cycle.htm Click here http://ga.water.usgs.gov/edu/mearth.html Biological Necessity Fact No. 1 Life cannot exist without water. Depending on age and gender, up to 60% of the human body is made up of water. It is the medium the body uses to regulate its temperature. Its presence in blood transports nutrients and minerals to the bodys cells. It is a major part of the mechanism that eliminates waste from the body. Fact No. 2 It must be continuously replaced. The human body dies in approximately 48 hours if water is unavailable. Cyclic Fact No. 1 Water has three forms solid (ice), liquid, and gas (water vapor). Fact No. 2 Heat and light from the sun raise the temperature of a drop of surface water and turn it into water vapor, which rises into the atmosphere. Fact No. 3 Water vapor and dust combine into particles in the atmosphere to form clouds. Fact No. 4 Wind makes the individual particles in the clouds collide and combine and the atmosphere cools the water vapor, which then forms drops. Fact No. 5 When the drops are heavy enough, they fall to the earth from the clouds as precipitation. Fact No. 6 It can take thousands of years for a drop of water to fully complete the hydrologic cycle. See hydrologic cycle: http://www.physicalgeography.net/fundamentals/8b.html |