The Physics
An encyclopedia of scientific essays

Volume of Earth's Rivers

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Bibliographic Entry Result
(w/surrounding text)
Spaulding & Namowitz. Heath Earth Science. New York: Heath, 1994: 148. "By one estimate, the amount of ground water is 50 times as much as all the water in the rivers and lakes." n/a
"Earth's Freshwaters." Macmillan Encyclopedia of Earth Sciences. New York: Simon & Schuster, 1996: 230.
Volume 103 km3Freshwater %
Freshwater lakes1000.3
1700 km3
Water Supply of the World. Infoplease Kid's Almanac. Original Source: US Geological Survey. "All rivers (average level); Volume (cubic miles), 300; percentage of total, 0.0001%" 1250 km3
Where is Earth's water located? Water Science for Schools. Original Source: US Geological Survey. "Water source, Rivers; Water volume in cubic miles, 300; percent of total water, 0.0001%" 1250 km3

Imagine being an astronaut traveling to the moon on a spaceship. After you arrive far above the Earth's surface and look back at it, you notice that the earth appears to be a blue ball shining in a black sky. You also notice, being the bright astronaut that you are, that the blue color overwhelms any other color on Earth. Water takes up nearly three-quarters of the Earth's surface. And if you journey below ground, you'll find even more water filling the gaps between the rocks.

Rivers are one of many bodies of water that cover the Earth's surface. Rivers make up, believe it or not, only one millionth of the water on Earth (1.7 × 103 km3 out of 1.35 × 109 km3). Earth's rivers vary in size. Some are so small they dry up during the dry seasons. Even though the list of Earth's rivers seems endless, each river has a story behind it. The Jordan River, in Israel-Jordan, is the most mentioned river in the Bible. The Indus River, in Tibet-Pakistan, is the source of one of the largest irrigation systems in the world. The Seine River, flows through Paris, France, where more than 30 bridges cross it. The Zambezi River, in Africa, and its Victoria Falls is one of the Seven Natural Wonders of the World.

Despite the beauty of rivers, they serve as sources of life and movement. Rivers are important to agriculture, in which its valleys and plains provide fertile land for farming. River water is used to irrigate farmland. Rivers serve as energy sources, to help run machines, and to generate enough electricity satisfy a fourth of the world's electric power needs. Rivers also serve for transportation and trade. Rivers are essential in maintaining activity, progress, and life.

Kerlly Bernabé -- 2000

Bibliographic Entry Result
(w/surrounding text)
Debenedetti, Pablo G. & H. Eugene Stanley. "Supercooled and Glassy Water." Physics Today. Vol. 56, No. 6 (June 2003): 40. "Water is not only fascinating, but it is also one of the most important and ubiquitous substances on Earth. There are 1.3 × 109 km3 of water in the oceans, 3.3 × 107 km3 in the polar ice caps, 2 × 105 km3 in glaciers, 105 km3 in lakes, and 1.2 × 103 km3 in rivers. In addition, 2.2 × 105 km3 of water fall annually as precipitation." 1200 km3

Editor's Supplement -- 2003