Common Water Issues
Common Water Issues
Water Properties
Emerging Contaminants
Water Quality Topics
Droughts: Things to Know
Find water science information and activities related to popular water topics and problems.
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Linking Selenium Sources to Ecosystems: Mining
Environmental sources of selenium (Se) such as from organic-enriched sedimentary deposits are geologic in nature and thus can occur on regional scales. A constructed map of the global distribution of Se source rocks informs potential areas of reconnaissance for modeling of Se risk including the phosphate deposits of southeastern Idaho and the coals of Appalachia.
Linking Selenium Sources to Ecosystems: Irrigation
Adverse effects of selenium (Se) on fish and waterfowl in wetlands receiving agricultural drainage occurred in the 1980s in the San Joaquin Valley of California. The identified mechanisms of Se enrichment helped resolve Se toxicity problems associated with irrigated agriculture in the arid West. Bioaccumulation of Se in ancient marine sediments is postulated as a primary pathway in source rocks.
Linking Selenium Sources to Ecosystems: Refining
The San Francisco Bay-Delta receives selenium (Se) internally from oil refineries and externally through riverine agricultural discharges. Predator species considered at risk from Se consume the estuary’s dominant bivalve, C. amurensis , an efficient bioaccumulator of Se. Modeling predicts site-specific ecological risk and derives a range of protective Se concentrations for use by decision-makers...
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.
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.
Flood Inundation Map (FIM) Libraries
The Flood Inundation Mapping Program focuses on developing flood inundation map libraries and helping communities pair those libraries with real-time stream data and National Weather Service flood forecasts to form a two-dimensional flood warning system. Together, these products can help communities estimate the extent of a flood and identify at-risk areas and resources in advance of floodwaters...
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.
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.
Flood Inundation Mapping - Loss Estimation
Using a flood inundation map library to estimate where floodwaters will go and how deep they will be is crucial for planning and preparing for floods. By performing loss-estimation modeling, the potential physical, economic, and social impacts of disasters can be calculated, helping communities anticipate the effects of flooding and identify specific strategies to reduce losses and speed recovery.
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...
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.
Urban Waters Federal Partnership—Little Calumet River (Northwest Indiana)
The USGS works with a wide range of cooperators to investigate many aspects of water quality. The newly integrated USGS Ohio-Kentucky-Indiana Water Science Center is assisting in furthering urban water-quality research in Northwest Indiana.