Geography Chapter 05: Water

The sun’s heat causes evaporation of water into vapour. When the water vapour cools down, it condenses and forms clouds. From there it may fall on the land or sea in the form of rain, snow or sleet.

The process by which water continually changes its form and circulates between oceans, atmosphere and land is known as the water cycle.

The major sources of fresh water are the rivers, ponds, springs and glaciers. The ocean bodies and the seas contain salty water.

Unlike the calm waters of ponds and lakes, ocean water keeps moving continuously. The movements that occur in oceans can be broadly categorised as: waves, tides and currents. When the water on the surface of the ocean rises and falls alternately, they are called waves. The rhythmic rise and fall of ocean water twice in a day is called a tide.

Ocean currents are streams of water flowing constantly on the ocean surface in definite directions. The ocean currents may be warm or cold.