The hydrological cycle

Prof. (Dr.) Sohan Raj Tater
THE hydrological cycle begins with evaporation from the surface of ocean or land, continues as air carries the water vapour to locations where it forms clouds and eventually precipitates out. It then continues when the precipitation is either absorbed into the ground or runs-off to the ocean, ready to begin the cycle over again in an endless loop. The amount of time needed for ground water to recharge can vary with the amount of intensity of precipitation.     
With world population expected to pass nine billion by mid-century, solutions to water scarcity problems are not going to come easy. Some have suggested that technology – such as large scale salt water desalination plants – could generate more water for the world use. But environmentalists argue that depleting ocean water is no answer and will only create other big problems. In any case, research and development into improving desalination technologies is ongoing, especially in Saudi Arabia, Israel and Japan. Already an estimated 11,000 desalination plants exist in some 120 countries around the world.
( To be concluded)