WATER ON THE MOVE...

Water cycle is powered by energy from the sun and by gravity. Incoming solar energy evaporates water from oceans, lakes, streams. Winds and air masses move water vapor over parts of the earth's surface. Falling temperatures cause the water to condense into tiny droplets that form clouds or fog. Water vapor collects on air particles and condenses at the dew point.



Precipitations falls back into the oceans, lakes etc and the rest over land. The precipitation replenishes the oceans and lakes, BUT surface water may cause soil erosion. Soil erosion moves soil and rock fragments from one place to another. Some of the surface water moves through the soil dissolving minerals from rocks. Some of this water is stored as groundwater. Evaporation and precipitation are processes that purify water by removing the impurities dissolved in water. In this way, the water cycle can be seen as a natural renewing agent of water quailty.