Water cycle
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Water cycle
Each year, the global water cycle delivers 110,000 cubic kilometers of water over land in the form of rain, sleet, and snow. (These values are approximate; various models have produced different estimates.) About 64 percent of that precipitation returns to the atmosphere through evaporation or transpiration (the use of water by plants, crops, grass
... See moreby an equal excess of precipitation over evaporation on land; consequently the volume of water carried to the sea by glaciers, rivers and coastal springs is close to 27 billion acre-feet per year. About 13 billion acre-feet is carried by 68 major river systems from a drainage area