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Surface Water

The world's surface-water resources—the water in rivers, lakes, and ice and snow—are vitally important to the everyday life of not only people, but to all life on, in, and above the Earth. And, of course, surface water is an intricate part of the water cycle, on which all life depends.

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Streamflow and the Water Cycle

What is streamflow? How do streams get their water? To learn about streamflow and its role in the water cycle, continue reading.
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Streamflow and the Water Cycle

What is streamflow? How do streams get their water? To learn about streamflow and its role in the water cycle, continue reading.
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Watersheds and Drainage Basins

When looking at the location of rivers and the amount of streamflow in rivers, the key concept is the river's "watershed". What is a watershed? Easy, if you are standing on ground right now, just look down. You're standing, and everyone is standing, in a watershed.
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Watersheds and Drainage Basins

When looking at the location of rivers and the amount of streamflow in rivers, the key concept is the river's "watershed". What is a watershed? Easy, if you are standing on ground right now, just look down. You're standing, and everyone is standing, in a watershed.
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La Ciencia del Agua para Escuelas

La Ciencia del Agua para Escuelas
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La Ciencia del Agua para Escuelas

La Ciencia del Agua para Escuelas
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Surface Water Photo Gallery

Learn about surface water using pictures.
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Surface Water Photo Gallery

Learn about surface water using pictures.
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Base Flow in Rivers

When a drought hits and little or no rain has fallen in a long time, you might expect small streams and even larger rivers to just dry up, right? In many cases, they don't. Streamflow might lessen to a trickle or so, but water continues to flow. How is that possible? Read on to find out how "base flow", which is water seeping into the stream from groundwater, helps keep water in streams during...
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Base Flow in Rivers

When a drought hits and little or no rain has fallen in a long time, you might expect small streams and even larger rivers to just dry up, right? In many cases, they don't. Streamflow might lessen to a trickle or so, but water continues to flow. How is that possible? Read on to find out how "base flow", which is water seeping into the stream from groundwater, helps keep water in streams during...
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Surface Water Information by Topic

Surface water is the most recognizable part of the water cycle that we can see. Lakes and rivers may be the first types of surface water that come to mind but don't forget those snowbanks in your front yard! We think of oceans when we think of surface water but did you remember to add glaciers to your list? The Water Science School has plenty to teach you about the different types of surface water...
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Surface Water Information by Topic

Surface water is the most recognizable part of the water cycle that we can see. Lakes and rivers may be the first types of surface water that come to mind but don't forget those snowbanks in your front yard! We think of oceans when we think of surface water but did you remember to add glaciers to your list? The Water Science School has plenty to teach you about the different types of surface water...
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How the U.S. Geological Survey Monitors Water

There are many pieces of equipment, both mechanical and electronic, that are installed at stream-monitoring sites all around the world to measure, record, and transmit both water-quantity and water-quality information. The U.S. Geological Survey (USGS) monitors "real-time" streamflow and water-quality conditions for thousands of streams nationwide.
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How the U.S. Geological Survey Monitors Water

There are many pieces of equipment, both mechanical and electronic, that are installed at stream-monitoring sites all around the world to measure, record, and transmit both water-quantity and water-quality information. The U.S. Geological Survey (USGS) monitors "real-time" streamflow and water-quality conditions for thousands of streams nationwide.
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How Streamflow is Measured

How can one tell how much water is flowing in a river? Can we simply measure how high the water has risen/fallen? The height of the surface of the water is called the stream stage or gage height. However, the USGS has more accurate ways of determining how much water is flowing in a river. Read on to learn more.
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How Streamflow is Measured

How can one tell how much water is flowing in a river? Can we simply measure how high the water has risen/fallen? The height of the surface of the water is called the stream stage or gage height. However, the USGS has more accurate ways of determining how much water is flowing in a river. Read on to learn more.
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Floods and Recurrence Intervals

A major storm or hurricane hits your area and on the radio you hear reference to a "100-year flood". But what exactly is a "100-year flood"? The term "100-year flood" is often used to describe a flood of great magnitude, but there is a lot more to it.
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Floods and Recurrence Intervals

A major storm or hurricane hits your area and on the radio you hear reference to a "100-year flood". But what exactly is a "100-year flood"? The term "100-year flood" is often used to describe a flood of great magnitude, but there is a lot more to it.
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Rivers of the World: World's Longest Rivers

Ever wondered about what is the longest river in the world? Or in the United States? Find out here.
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Rivers of the World: World's Longest Rivers

Ever wondered about what is the longest river in the world? Or in the United States? Find out here.
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Sediment and Suspended Sediment

Water in nature is never really totally clear, especially in surface water, such as rivers and lakes. Water has color and some extent of dissolved and suspended material, usually dirt particles (suspended sediment). Suspended sediment is an important factor in determining the quality of water.
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Sediment and Suspended Sediment

Water in nature is never really totally clear, especially in surface water, such as rivers and lakes. Water has color and some extent of dissolved and suspended material, usually dirt particles (suspended sediment). Suspended sediment is an important factor in determining the quality of water.
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Monthly and Yearly Streamflow Patterns

The U.S. Geological Survey (USGS) has been measuring streamflow at thousands of streams for over a century. When extensive records of past streamflows exist, it is possible to see a pattern of streamflow variation by month and season.
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Monthly and Yearly Streamflow Patterns

The U.S. Geological Survey (USGS) has been measuring streamflow at thousands of streams for over a century. When extensive records of past streamflows exist, it is possible to see a pattern of streamflow variation by month and season.
Learn More