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Measuring and Monitoring Water

Find water science information and activities related to how the USGS measures and monitors water resources.

Filter Total Items: 180

Volatile Organic Compounds (VOCs)

Volatile organic compounds (VOCs) are chemicals that both vaporize into air and dissolve in water. VOCs are pervasive in daily life, because they’re used in industry, agriculture, transportation, and day-to-day activities around the home. Once released into groundwater, many VOCs are persistent and can migrate to drinking-water supply wells.
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Volatile Organic Compounds (VOCs)

Volatile organic compounds (VOCs) are chemicals that both vaporize into air and dissolve in water. VOCs are pervasive in daily life, because they’re used in industry, agriculture, transportation, and day-to-day activities around the home. Once released into groundwater, many VOCs are persistent and can migrate to drinking-water supply wells.
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Oxidation/Reduction (Redox)

The redox state of groundwater—whether the groundwater is oxic (oxidized) or anoxic (reduced)—has profound implications for groundwater quality. Knowing the redox conditions of groundwater can help determine whether it contains elevated levels of many contaminants, including arsenic, nitrate, and even some manmade contaminants.
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Oxidation/Reduction (Redox)

The redox state of groundwater—whether the groundwater is oxic (oxidized) or anoxic (reduced)—has profound implications for groundwater quality. Knowing the redox conditions of groundwater can help determine whether it contains elevated levels of many contaminants, including arsenic, nitrate, and even some manmade contaminants.
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Everything you need to know about SPARROW

What is SPARROW? SPARROW (SPAtially Referenced Regression On Watershed attributes) is a watershed modeling technique for relating water-quality measurements made at a network of monitoring stations to attributes of the watersheds such as contaminant sources and environmental factors that affect rates of delivery to streams and in-stream processing. The core of the model consists of a nonlinear...
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Everything you need to know about SPARROW

What is SPARROW? SPARROW (SPAtially Referenced Regression On Watershed attributes) is a watershed modeling technique for relating water-quality measurements made at a network of monitoring stations to attributes of the watersheds such as contaminant sources and environmental factors that affect rates of delivery to streams and in-stream processing. The core of the model consists of a nonlinear...
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Linking Selenium Sources to Ecosystems: Modeling

Selenium (Se) as a contaminant of ecosystems is bioaccumulative and causes reproductive effects in fish and wildlife. Ecosystem-scale Se modeling predicts Se bioaccumulation based on dietary biodynamics within site-specific food webs. The model can be used to forecast Se toxicity under different management or regulatory proposals or to translate a tissue guideline to a dissolved guideline.
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Linking Selenium Sources to Ecosystems: Modeling

Selenium (Se) as a contaminant of ecosystems is bioaccumulative and causes reproductive effects in fish and wildlife. Ecosystem-scale Se modeling predicts Se bioaccumulation based on dietary biodynamics within site-specific food webs. The model can be used to forecast Se toxicity under different management or regulatory proposals or to translate a tissue guideline to a dissolved guideline.
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National Water-Quality Assessment (NAWQA): 1991-2012

In 1991, Congress established the National Water-Quality Assessment (NAWQA) Project to address where, when, why, and how the Nation's water quality has changed, or is likely to change in the future, in response to human activities and natural factors. This page discusses the first two decadal cycles of NAWQA research from 1991 through 2012.
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National Water-Quality Assessment (NAWQA): 1991-2012

In 1991, Congress established the National Water-Quality Assessment (NAWQA) Project to address where, when, why, and how the Nation's water quality has changed, or is likely to change in the future, in response to human activities and natural factors. This page discusses the first two decadal cycles of NAWQA research from 1991 through 2012.
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Water-Use Terminology

The following terms have been used in one or more of the water-use publications. The comparison of water-use categories over the history of these reports may also help clarify the use of some of the terms.
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Water-Use Terminology

The following terms have been used in one or more of the water-use publications. The comparison of water-use categories over the history of these reports may also help clarify the use of some of the terms.
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National Brackish Groundwater Assessment

All water naturally contains dissolved solids that can make it "brackish" or distastefully salty. The amount of freshwater for drinking-water, agricultural, industrial, and environmental needs has declined in many areas and has led to concerns about future availability. The USGS conducted a national assessment of brackish aquifers that could supplement or replace freshwater sources.
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National Brackish Groundwater Assessment

All water naturally contains dissolved solids that can make it "brackish" or distastefully salty. The amount of freshwater for drinking-water, agricultural, industrial, and environmental needs has declined in many areas and has led to concerns about future availability. The USGS conducted a national assessment of brackish aquifers that could supplement or replace freshwater sources.
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Emerging Flood Inundation Mapping Technologies

The following technologies represent state-of-the-art tools, methodologies, and techniques that the USGS and our partners are researching and testing. Most of these techniques are experimental and not publicly available, but could significantly improve our ability to plan for and respond to flooding events in the future.
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Emerging Flood Inundation Mapping Technologies

The following technologies represent state-of-the-art tools, methodologies, and techniques that the USGS and our partners are researching and testing. Most of these techniques are experimental and not publicly available, but could significantly improve our ability to plan for and respond to flooding events in the future.
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2011 - The Year of the Flood

2011 proved to be another record-breaking flood year in the United States. USGS Water Science Center personnel from North Dakota to Louisiana measured springtime floods on the Red River of the North, the Ohio River, the Mississippi River, and many tributaries. The Missouri River and its tributaries saw record-breaking snow-melt runoff through the summer, followed closely by Hurricane Irene and...
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2011 - The Year of the Flood

2011 proved to be another record-breaking flood year in the United States. USGS Water Science Center personnel from North Dakota to Louisiana measured springtime floods on the Red River of the North, the Ohio River, the Mississippi River, and many tributaries. The Missouri River and its tributaries saw record-breaking snow-melt runoff through the summer, followed closely by Hurricane Irene and...
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Water-Quality Quick Links

Looking for data? Maps? Use the links below to quickly access some of the most frequently visited USGS web pages on water quality.
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Water-Quality Quick Links

Looking for data? Maps? Use the links below to quickly access some of the most frequently visited USGS web pages on water quality.
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Urban Waters Federal Partnership—Bronx and Harlem River Watersheds (New York, N.Y.)

The Harlem and Bronx Rivers provide ecological and social resources in an intensively urban area. Connecting people to rivers requires clean water—the USGS is helping to assess the efficacy of green infrastructure to improve the quality of stormwater that flows into the rivers.
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Urban Waters Federal Partnership—Bronx and Harlem River Watersheds (New York, N.Y.)

The Harlem and Bronx Rivers provide ecological and social resources in an intensively urban area. Connecting people to rivers requires clean water—the USGS is helping to assess the efficacy of green infrastructure to improve the quality of stormwater that flows into the rivers.
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Urban Waters Federal Partnership—Middle Rio Grande (Albuquerque, N. Mex.)

The Valle de Oro National Wildlife Refuge, just 7 miles south of downtown Albuquerque on the Rio Grande, will reconnect people, especially young people, with nature in this highly populated area. The USGS is gathering data that will help gauge the success of habitat restoration efforts.
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Urban Waters Federal Partnership—Middle Rio Grande (Albuquerque, N. Mex.)

The Valle de Oro National Wildlife Refuge, just 7 miles south of downtown Albuquerque on the Rio Grande, will reconnect people, especially young people, with nature in this highly populated area. The USGS is gathering data that will help gauge the success of habitat restoration efforts.
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