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Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.
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Educational materials from the U.S. Geological Survey
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Educational materials from the U.S. Geological Survey
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Educational materials from the U.S. Geological Survey
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What happens to nutrients in offstream reservoirs in the lower South Platte River Basin?
The practice of storing South Platte River water in offstream reservoirs reduces nutrient concentrations but also contributes to the growth of algae, which may adversely affect the recreational use of the reservoirs. Results of a study of five offstream reservoirs in the lower South Platte River Basin during the 1995 irrigation season showed that the reservoirs trapped 20 to 88 percent of incoming nitrogen and phosphorus, except for phosphorus in one reservoir. Total nitrogen concentrations in the reservoirs were highest in March and decreased through September, largely as a result of uptake by algae and other aquatic life for growth. Total phosphorus concentrations in the reservoirs were more variable because of the recycling of phosphorus by aquatic life. Chlorophyll-a concentrations indicated that the amount of algae in all reservoirs increased during the summer and that all reservoirs were eutrophic. This study was done by the U.S. Geological Survey as part of the National Water-Quality Assessment (NAWQA) Program.
Geohydrology of recharge and seawater intrusion in the Pajaro Valley, Santa Cruz and Monterey counties, California
The U.S. Geological Survey (USGS) in cooperation with the Pajaro Valley Water Management Agency (PVWMA), has completed the collection and analyses of geologic, hydrologic, geophysical, and geochemical data in the coastal aquifer systems of the Pajaro Valley (fig. 1). These data were collected to delineate the geohydrologic framework of seawater intrusion, as well as, the source, age, and movement of ground water in the coastal aquifer systems (Hanson, 2003).
United States Geological Survey: Programs in Utah
The U.S. Geological Survey (USGS) has been collecting hydrologic data relating to the occurrence, quantity, and quality of water resources in Utah since 1889. The USGS maintains a network of about 200 gaging stations on rivers, streams, lakes, and reservoirs in Utah and parts of Wyoming, Idaho, and Arizona and monitors about 1,100 wells throughout the State (fig. 1). Within this network, water-quality samples are collected at 15 surface-water sites and about 185 wells. Additional water-quality samples are collected throughout Utah as part of investigative studies in which the hydrology of specific areas is examined.
U. S. Geological Survey programs in Utah
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Midcontinent urban corridor geologic mapping project
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Watershed-scale research from many perspectives : the Interdisciplinary Research Initiative at the Shingobee River headwaters area, Minnesota
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Center for Integration of Natural Disaster Information
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The Advanced National Seismic System; management and implementation
What is the Advanced National Seismic System? The Advanced National Seismic System (ANSS) is designed to organize, modernize, and standardize operations of seismic networks in the United States to improve the Nation’s ability to respond effectively to damaging earthquakes, volcanoes, and tsunamis. To achieve this, the ANSS will link more than 7,000 national, regional and urban monitoring stations in real time
U.S. Geological Survey 2002 petroleum resource assessment of the National Petroleum Reserve in Alaska (NPRA)
A new USGS assessment concludes that NPRA holds signicantly greater petroleum resources than previously estimated. Technically recoverable, undiscovered oil beneath the Federal part of NPRA likely ranges between 5.9 and 13.2 billion barrels, with a mean (expected) value of 9.3 billion barrels. An estimated 1.3 to 5.6 billion barrels of those technically recoverable oil resources is economically recoverable at market prices of $22 to $30 per barrel. Technically recoverable, undiscovered nonassociated natural gas for the same area likely ranges between 39.1 and 83.2 trillion cubic feet, with a mean (expected) value of 59.7 trillion cubic feet. The economic viability of this gas will depend on the availability of a natural-gas pipeline for transport to market.
Surface Water in Hawaii
Surface water in Hawaii is a valued resource as well as a potential threat to human lives and property. The surface-water resources of Hawaii are of significant economic, ecologic, cultural, and aesthetic importance. Streams supply more than 50 percent of the irrigation water in Hawaii, and although streams supply only a few percent of the drinking water statewide, surface water is the main source of drinking water in some places. Streams also are a source of hydroelectric power, provide important riparian and instream habitats for many unique native species, support traditional and customary Hawaiian gathering rights and the practice of taro cultivation, and possess valued aesthetic qualities. Streams affect the physical, chemical, and aesthetic quality of receiving waters, such as estuaries, bays, and nearshore waters, which are critical to the tourism-based economy of the islands. Streams in Hawaii pose a danger because of their flashy nature; a stream's stage, or water level, can rise several feet in less than an hour during periods of intense rainfall. Streams in Hawaii are flashy because rainfall is intense, drainage basins are small, basins and streams are steep, and channel storage is limited. Streamflow generated during periods of heavy rainfall has led to loss of property and human lives in Hawaii. Most Hawaiian streams originate in the mountainous interiors of the islands and terminate at the coast. Streams are significant sculptors of the Hawaiian landscape because of the erosive power of the water they convey. In geologically young areas, such as much of the southern part of the island of Hawaii, well-defined stream channels have not developed because the permeability of the surface rocks generally is so high that rainfall infiltrates before flowing for significant distances on the surface. In geologically older areas that have received significant rainfall, streams and mass wasting have carved out large valleys.
United States Geological Survey, Programs in Vermont
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U. S. Geological Survey programs in Vermont
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Revision and product generation software
The U.S. Geological Survey (USGS) developed revision and product generation (RevPG) software for updating digital line graph (DLG) data and producing maps from such data. This software is based on ARC/INFO, a geographic information system from Environmental Systems Resource Institute (ESRI). RevPG consists of ARC/INFO Arc Macro Language (AML) programs, C routines, and interface menus that permit operators to collect vector data using aerial images, to symbolize the data on-screen, and to produce plots and color-separated files for use in printing maps.