Water Cycle2

The Water Cycle Consists of four distinct stages: Storage, evaporation , precipitation and run off . Water may be stored temporarily in the ground; in oceans, lakes , and rivers ; and in ice caps and glaciers. It evaporates from the Earth’s surface, condenses in clouds, falls back to the earth as precipitation (rain or snow), and eventually either runs into the seas or reevaporates into the atmosphere. 1. Precipitation:- Precipitation occurs when water vapor in the atmosphere Condenses into clouds and falls to the earth. Precipitation can take a variety of forms, including rain, snow etc. About 300 cubic kilometers of precipitation falls each day.

2. Storage:- The water from precipitation is stored on the earth in both liquid and solid forms. Of the 1.4 billion cubic kilometers of water on earth, slightly more than 97 percent is salt water stored in the oceans.

3. RunOff:- Water that flows down streams and rivers is called surface runoff. Everyday about 100 cubic kilometers of water flows into the seas from the world’s rivers .Water reaches rivers in the form of either overland flow or groundwater flow; it then flows downstream .Overland flow occurs during and shortly after intense rainstorms or periods of rapid melting of snow and rice. It can raise river levels rapidly and may produce floods. Groundwater flow runs through rocks and soil. 4. Evaporation and Transpiration:- Evaporation is the process by which water in the ocean and on land changes to water vapor and enters the atmosphere as a gas. Evaporation from plants is called transpiration. The evaporation rate increases with temperature, sunlight intensity, wind speed and ground moisture, and it decreases as the humidity of the air increases. 5. Condensation:- Water vapor cools as it rises, condensing into droplets of water to form clouds. Precipitation falls from the clouds and the water returns to earth, continuing the hydrologic cycle. Almost all the water on earth has passed through the water cycle countless times.