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At least 523 records · Page 29Linked to original sources
USGS2006

Bedrock Geologic Map of New Hampshire, a Digital Representation of Lyons and Others 1997 Map and Ancillary Files

The New Hampshire Geological Survey collects data and performs research on the land, mineral, and water resources of the State, and disseminates the findings of such research to the public through maps, reports, and other publications. The Bedrock Geologic Map of New Hampshire, by John B. Lyons, Wallace A. Bothner, Robert H. Moench, and James B. Thompson, was published in paper format by the U.S. Geological Survey (USGS) in 1997. The online version of this CD contains digital datasets of the State map that are intended to assist the professional geologist, land-use planners, water resource professionals, and engineers and to inform the interested layperson. In addition to the bedrock geology, the datasets include geopolitical and hydrologic information, such as political boundaries, quadrangle boundaries, hydrologic units, and water-well data. A more thorough explanation for each of these datasets may be found in the accompanying metadata files. The data are spatially referenced and may be used in a geographic information system (GIS). ArcExplorer, the Environmental Systems Research Institute's (ESRI) free GIS data viewer, is available at http://www.esri.com/software/arcexplorer. ArcExplorer provides basic functions that are needed to harness the power and versatility of the spatial datasets. Additional information on the viewer and other ESRI products may be found on the ArcExplorer website. Although extensive review and revisions of the data have been performed by the USGS and the New Hampshire Geological Survey, these data represent interpretations made by professional geologists using the best available data, and are intended to provide general geologic information. Use of these data at scales larger than 1:250,000 will not provide greater accuracy. The data are not intended to replace site-specific or specific-use investigations. The U.S. Geological Survey, New Hampshire Geological Survey, and State of New Hampshire make no representation or warranty, expressed or implied, regarding the use, accuracy, or completeness of the data presented herein, or from a map printed from these data; nor shall the act of distribution constitute any such warranty. The New Hampshire Geological Survey disclaims any legal responsibility or liability for interpretations made from the map, or decisions based thereon. For more information on New Hampshire Geological Survey programs please visit the State's website at http://des.nh.gov/Geology/. New Hampshire Geographically Referenced Analysis and Information Transfer System (NH GRANIT) provides access to statewide GIS (http://www.granit.unh.edu/). Questions about this CD or about other datasets should be directed to the New Hampshire Department of Environmental Services.

Data Series↗
USGS2018

Development of a hydraulic model and flood-inundation maps for the Wabash River near the Interstate 64 Bridge near Grayville, Illinois

A two-dimensional hydraulic model and digital flood‑inundation maps were developed for a 30-mile reach of the Wabash River near the Interstate 64 Bridge near Grayville, Illinois. The flood-inundation maps, which can be accessed through the U.S. Geological Survey (USGS) Flood Inundation Mapping Science web site at http://water.usgs.gov/osw/flood_inundation/ , depict estimates of the areal extent and depth of flooding corresponding to selected water levels (stages) at the USGS streamgage on the Wabash River at Mount Carmel, Ill (USGS station number 03377500). Near-real-time stages at this streamgage may be obtained on the internet from the USGS National Water Information System at http://waterdata.usgs.gov/ or the National Weather Service (NWS) Advanced Hydrologic Prediction Service (AHPS) at http://water.weather.gov/ahps/ , which also forecasts flood hydrographs at this site (NWS AHPS site MCRI2). The NWS AHPS forecasts peak stage information that may be used with the maps developed in this study to show predicted areas of flood inundation. Flood elevations were computed for the Wabash River reach by means of a two-dimensional, finite-volume numerical modeling application for river hydraulics. The hydraulic model was calibrated by using global positioning system measurements of water-surface elevation and the current stage-discharge relation at both USGS streamgage 03377500, Wabash River at Mount Carmel, Ill., and USGS streamgage 03378500, Wabash River at New Harmony, Indiana. The calibrated hydraulic model was then used to compute 27 water-surface elevations for flood stages at 1-foot (ft) intervals referenced to the streamgage datum and ranging from less than the action stage (9 ft) to the highest stage (35 ft) of the current stage-discharge rating curve. The simulated water‑surface elevations were then combined with a geographic information system digital elevation model, derived from light detection and ranging data, to delineate the area flooded at each water level. The availability of these maps, along with information on the internet regarding current stage from the USGS streamgage at Mount Carmel, Ill., and forecasted stream stages from the NWS AHPS, provides emergency management personnel and residents with information that is critical for flood-response activities such as evacuations and road closures, as well as for postflood recovery efforts.

Illinois↗
USGS1996

Use of a ground-water flow model with particle tracking to evaluate ground-water vulnerability, Clark County, Washington

A ground-water flow model was used in conjunction with particle tracking to evaluate ground-water vulnerability in Clark County, Washington. Using the particle-tracking program, particles were placed in every cell of the flow model (about 60,000 particles) and tracked backwards in time and space upgradient along flow paths to their recharge points. A new computer program was developed that interfaces the results from a particle-tracking program with a geographic information system (GIS). The GIS was used to display and analyze the particle-tracking results. Ground-water vulnerability was evaluated by selecting parts of the ground-water flow system and combining the results with ancillary information stored in the GIS to determine recharge areas, characteristics of recharge areas, downgradient impact of land use at recharge areas, and age of ground water. Maps of the recharge areas for each hydrogeologic unit illustrate the presence of local, intermediate, or regional ground-water flow systems and emphasize the three-dimensional nature of the ground-water flow system in Clark County. Maps of the recharge points for each hydrogeologic unit were overlaid with maps depicting aquifer sensitivity as determined by DRASTIC (a measure of the pollution potential of ground water, based on the intrinsic characteristics of the near-surface unsaturated and saturated zones) and recharge from on-site waste-disposal systems. A large number of recharge areas were identified, particularly in southern Clark County, that have a high aquifer sensitivity, coincide with areas of recharge from on-site waste-disposal systems, or both. Using the GIS, the characteristics of the recharge areas were related to the downgradient parts of the ground-water system that will eventually receive flow that has recharged through these areas. The aquifer sensitivity, as indicated by DRASTIC, of the recharge areas for downgradient parts of the flow system was mapped for each hydrogeologic unit. A number of public-supply wells in Clark County may be receiving a component of water that recharged in areas that are more conducive to contaminant entry. The aquifer sensitivity maps illustrate a critical deficiency in the DRASTIC methodology: the failure to account for the dynamics of the ground-water flow system. DRASTIC indices calculated for a particular location thus do not necessarily reflect the conditions of the ground-water resources at the recharge areas to that particular location. Each hydrogeologic unit was also mapped to highlight those areas that will eventually receive flow from recharge areas with on-site waste-disposal systems. Most public-supply wells in southern Clark County may eventually receive a component of water that was recharged from on-site waste-disposal systems.Traveltimes from particle tracking were used to estimate the minimum and maximum age of ground water within each model-grid cell. Chlorofluorocarbon (CFC)-age dating of ground water from 51 wells was used to calibrate effective porosity values used for the particle- tracking program by comparison of ground-water ages determined through the use of the CFC-age dating with those calculated by the particle- tracking program. There was a 76 percent agreement in predicting the presence of modern water in the 51 wells as determined using CFCs and calculated by the particle-tracking program. Maps showing the age of ground water were prepared for all the hydrogeologic units. Areas with the youngest ground-water ages are expected to be at greatest risk for contamination from anthropogenic sources. Comparison of these maps with maps of public- supply wells in Clark County indicates that most of these wells may withdraw ground water that is, in part, less than 100 years old, and in many instances less than 10 years old. Results of the analysis showed that a single particle-tracking analysis simulating advective transport can be used to evaluate ground-water vulnerability for any part of a ground-wate

Open-File Report↗
USGS1999

Management of groundwater supply and water quality in the Los Angeles Basin, California

Water use and water needs in the coastal Los Angeles Basin in California have been very closely tied to the development of the region during the last 150 years. The first water wells were drilled in the mid-1800s. Currently about 40% of the water supply (9.4 m3 s-1) in the region is provided by groundwater. Other sources of water supply include reclaimed water and surface water imported from Owens Valley, the Colorado River, and northern California. Increasing groundwater use in the basin led to over-abstraction and seawater instrusion. Because of this, an important component of water management in the area has been the artificial recharge of local, imported, and reclaimed water which is spread in ponds and injected in wells to recharge the aquifer system and control seawater intrusion. The US Geological Survey (USGS) is working co-operatively with the Water Replenishment District of Southern California to evaluate the hydraulic and water-quality effects of these recharge operations and to assess the potential impacts of alternative water-management strategies, including changes in pumping and increases in the use of reclaimed water. As part of this work, the USGS has developed a geographic information system (GIS), collected water-quality and geohydrological data from new and existing wells, and developed a multi-aquifer regional groundwater flow model. Chemical and isotopic data were used to identify the age and source of recharge to groundwater throughout the study area. This information is key to understanding the fate of artificially recharged water and helps define the three-dimensional groundwater flow system. The geohydrological data, especially the geophysical and geological data collected from 11 newly installed multi-completion monitoring wells, were used to redefine the regional hydrostratigraphy. The groundwater flow model is being used to enhance the understanding of the geohydrological system and to quantitatively evaluate new water-management strategies.As part of the work aimed at evaluating the hydraulic and water-quality effects of recharge operations and to assess the potential impacts of alternative water-management strategies, the US Geological Survey (USGS), has developed a geographic information system (GIS), collected water-quality and geohydrological data from new and existing wells, and developed a multi-aquifer regional groundwater flow model. At present, the developed model is being used to enhance the understanding of the geohydrological system and to quantitatively evaluate new water-management strategies.

Conference Paper↗
USGS1996

Evaluation of the Surface-Water Quantity, Surface-Water Quality, and Rainfall Data-Collection Programs in Hawaii, 1994

This report documents the results of an evaluation of the surface-water quantity, surface-water quality, and rainfall data-collection programs in Hawaii. Fourteen specific issues and related goals were identified for the surface-water quantity program and a geographic information systems (GIS) data base was developed summarizing information for all surface-water stream gages that have been operated in Hawaii by the U.S. Geological Survey. Changes in status, which for some gages includes discontinuing operation, need to be considered at 42 sites where data are currently collected. The current surface-water quantity data base was determined to be adequate to address only two of the 14 specific issues and related goals. Alternatives were identified to address the areas where future issues and goals could not be adequately addressed. Options include new and expanded data collection, use of regional regression analyses, hydrologic and hydraulic modeling, and analysis and publication of existing data. A total of 47 streams were identified where additional stream-gaging stations are needed. Evaluation of the surface-water quality program was limited to a description of the U.S. Geological Survey's historical and existing programs and available analyses of data. Limitations of the program are described which primarily included lack of data regarding suspended sediment, land-use effects, quality of stream discharge to oceans, background water quality and nonpoint sources of contamination. Evaluation of the rainfall data program indicated that identified future goals could be discussed as either regional, systems related, current needs, forecasting, water quality, or trend analysis related. To address these goals, data from about 2,000 rain gages, 528 of which are active, are available. Data were found to only partially meet identified goals. Alternatives discussed to address the limitations include the need for more recording gages, primarily in areas of high rainfall. Another area of concern was the potential that many plantations will close and the effect these closings would have on continued operation of the important long-term gages they operate. Evaluation of data-collection programs in Hawaii needs to be an ongoing process. Equally important, data being collected need to be summarized and made available through data bases and published reports.

Water-Resources Investigations Report↗
USGS2017

Water resources of Concordia Parish, Louisiana

Introduction Information concerning the availability, use, and quality of water in Concordia Parish, Louisiana, is critical for proper water-supply management. The purpose of this fact sheet is to present information that can be used by water managers, parish residents, and others for stewardship of this vital resource. Information on the availability, past and current use, use trends, and water quality from groundwater and surface-water sources in the parish is presented. Previously published reports and data stored in the U.S. Geological Survey’s National Water Information System are the primary sources of the information presented here. In 2010, over 50 million gallons per day (Mgal/d) of water were withdrawn in Concordia Parish, including about 28.7 Mgal/d from groundwater sources and 22.3 Mgal/d from surface-water sources. Withdrawals for agricultural use, composed of livestock, rice irrigation, general irrigation, and aquaculture accounted for about 77 percent (39.2 Mgal/d) of the total water withdrawn. Other categories of use included public supply, power generation, and rural domestic. Water-use data collected at 5-year intervals from 1960 to 2010 indicated that water withdrawals peaked in 2010.

Louisiana↗
USGS2017

Water resources of Iberia Parish, Louisiana

Introduction Information concerning the availability, use, and quality of water in Iberia Parish, Louisiana, is critical for proper water-resource management. This fact sheet summarizes the availability, past and current use, use trends, and water quality from groundwater and surface-water sources in the parish for water managers, parish residents, and others to assist in stewardship of this vital resource. Previously published reports and data stored in the U.S. Geological Survey’s National Water Information System are the primary sources of the information presented here. In 2010, about 31.24 million gallons per day (Mgal/d) of water were withdrawn in Iberia Parish, Louisiana, including about 23.13 Mgal/d from groundwater sources and 8.11 Mgal/d from surface-water sources. Withdrawals for public supply and industrial use each accounted for about 32 percent of the total water withdrawn. Other water-use categories included rural domestic, livestock, rice irrigation, general irrigation, and aquaculture. Water-use data collected at 5-year intervals from 1960 to 2010 indicated that water withdrawals in Iberia Parish peaked at about 58.57 Mgal/d in 1975.

Louisiana↗
USGS2017

Water resources of Catahoula Parish, Louisiana

Introduction Information concerning the availability, use, and quality of water in Catahoula Parish, Louisiana, is critical for proper water-supply management. The purpose of this fact sheet is to present information that can be used by water managers, parish residents, and others for stewardship of this vital resource. Information on the availability, past and current use, use trends, and water quality from groundwater and surface-water sources in the parish is presented. Previously published reports and data stored in the U.S. Geological Survey’s National Water Information System are the primary sources of the information presented here. In 2010, 30.01 million gallons per day (Mgal/d) of water were withdrawn in Catahoula Parish, Louisiana, including about 22.63 Mgal/d from groundwater sources and 7.38 Mgal/d from surface-water sources. Withdrawals for agricultural use, composed of aquaculture, general irrigation, livestock, and rice irrigation, accounted for about 93 percent (28.05 Mgal/d) of the total water withdrawn. Other categories of use included public supply and rural domestic. Water-use data collected at 5-year intervals from 1960 to 2010 indicated that water withdrawals peaked in 2000 at 30.99 Mgal/d.

Louisiana↗
USGS2008

Application of Wind Fetch and Wave Models for Habitat Rehabilitation and Enhancement Projects

Models based upon coastal engineering equations have been developed to quantify wind fetch length and several physical wave characteristics including significant height, length, peak period, maximum orbital velocity, and shear stress. These models, developed using Environmental Systems Research Institute's ArcGIS 9.2 Geographic Information System platform, were used to quantify differences in proposed island construction designs for three Habitat Rehabilitation and Enhancement Projects (HREPs) in the U.S. Army Corps of Engineers St. Paul District (Capoli Slough and Harpers Slough) and St. Louis District (Swan Lake). Weighted wind fetch was calculated using land cover data supplied by the Long Term Resource Monitoring Program (LTRMP) for each island design scenario for all three HREPs. Figures and graphs were created to depict the results of this analysis. The difference in weighted wind fetch from existing conditions to each potential future island design was calculated for Capoli and Harpers Slough HREPs. A simplistic method for calculating sediment suspension probability was also applied to the HREPs in the St. Paul District. This analysis involved determining the percentage of days that maximum orbital wave velocity calculated over the growing seasons of 2002-2007 exceeded a threshold value taken from the literature where fine unconsolidated sediments may become suspended. This analysis also evaluated the difference in sediment suspension probability from existing conditions to the potential island designs. Bathymetric data used in the analysis were collected from the LTRMP and wind direction and magnitude data were collected from the National Oceanic and Atmospheric Administration, National Climatic Data Center.

Open-File Report↗
USGS1993

National Water Quality Assessment Program; preliminary assessment of nitrate distribution in ground water in the Georgia-Florida Coastal Plain study unit, 1972-90

The U.S. Geological Survey has implemented the National Water Quality Assessment program to describe the quality of the surface- and ground- water resources in 60 large areas or study units in the Nation. The Georgia-Florida Coastal Plain study unit was one of the first 20 selected for study when the full-scale program was implemented in 1991. The study unit has an area of about 54,000 square miles and is located on the south- eastern coast of the United States. The primary source of water supply in this study unit is ground-water from the Upper Floridan aquifer of the Floridan aquifer system. The Upper Floridan aquifer is unconfined or semiconfined in some parts of the study unit, but in other parts is confined by the overlying surficial aquifer system and other confining units. The surficial aquifer system is also used for water supply in some parts of the study unit. Three land-resource areas have been delineated in the study unit on the basis of generalized soil classifications: the Central Florida Ridge, Coastal Flatwoods, and Southern Coastal Plain. Predominant land use and land cover as classified in the 1970's, are forest, agriculture, wetlands, and urban. Nitrate data for water from the Upper Floridan aquifer and the surficial aquifer system were obtained from the National Water Information System data base of the U.S. Geological Survey for the years 1972- 90. In the Upper Floridan aquifer, the highest median nitrate (as nitrogen) concentrations (0.43 and 0.26 milligrams per liter) were in water samples from wells in agricultural and urban areas where the aquifer was unconfined or semiconfined. The maximum contaminant level for nitrate (as nitrogen) in drinking water of 10 milligrams per liter was exceeded in 25 of the 726 water samples from this aquifer. These 25 samples were from wells in urban areas. In water samples from the surficial aquifer system, the highest median nitrate concentration, 8.7 milligrams per liter, was for water samples from agricultural areas in the Central Florida Ridge area. Nitrate (as nitrogen) concentrations exceeded 10 milligrams per liter in 50 of the 421 water samples from wells completed in the surficial aquifer system. Most of these 50 water samples were from wells in agricultural and urban areas (sewage spraying areas) in the Central Florida Ridge.

Florida, Georgia↗
USGS1999

Calculation of coal resources using ARC/INFO and Earth Vision; methodology for the National Coal Resource Assessment

This report documents a comparison of two methods of resource calculation that are being used in the National Coal Resource Assessment project of the U.S. Geological Survey (USGS). Tewalt (1998) discusses the history of using computer software packages such as GARNET (Graphic Analysis of Resources using Numerical Evaluation Techniques), GRASS (Geographic Resource Analysis Support System), and the vector-based geographic information system (GIS) ARC/INFO (ESRI, 1998) to calculate coal resources within the USGS. The study discussed here, compares resource calculations using ARC/INFO* (ESRI, 1998) and EarthVision (EV)* (Dynamic Graphics, Inc. 1997) for the coal-bearing John Henry Member of the Straight Cliffs Formation of Late Cretaceous age in the Kaiparowits Plateau of southern Utah. Coal resource estimates in the Kaiparowits Plateau using ARC/INFO are reported in Hettinger, and others, 1996.

Open-File Report↗
USGS1998

Combining satellite data with ancillary data to produce a refined land-use/land-cover map

As part of the U.S. Geological Survey's National Water-Quality Assessment Program in the Western Lake Michigan Drainages Study Unit, a current map of land use and land cover is needed to gain a better understanding of how land use and land cover may influence water quality. Satellite data from the Landsat Thematic Mapper provides a means to map and measure the type and amount of various land-cover types across the Study Unit and can be easily updated as changes occur in the landscape or in water quality. Translating these land cover categories to land use, however, requires the use of other thematic maps or ancillary data layers, such as wetland inventories, population data, or road networks. This report describes a process of (1) using satellite imagery to produce a land-cover map for the Fox/Wolf River basin, a portion of the Western Lake Michigan Drainages NAWQA Study Unit and (2) improving the satellite-derived land-cover map by using other thematic maps. The multiple data layers are processed in a geographic information system (GIS), and the combination provides more information than individual sources alone.

Michigan, Wisconsin↗
USGS1993

Finite-element mesh generation from mappable features

A vector-based geographical information system (GIS) is used to generate a variably-sized triangular element finite-element mesh from mappable features. Important digitally-mapped features are automatically linked to nodes in the finite-element model, ensuring an efficient, virtually error-free alternative to the tedious process of mesh design and data-input preparation by other methods. The procedure permits the user to work interactively with graphically-displayed hydrologic information about the study area allowing different mesh sizes to be used as needed, based on hydrologic complexity. The mesh-generaiion programs are stand-alone macros within the GIS that set up the basic data defining a finite-element mesh for many different finite-element model programs.

International Journal of Geographical Information ↗
USGS2023

Development and application of a risk assessment tool for aquatic invasive species in the international Rainy-Lake of the Woods Basin, United States and Canada

The Rainy-Lake of the Woods Basin covers 70,000 square kilometers in mid-central North America and is contained within the Provinces of Ontario and Manitoba in Canada and the State of Minnesota in the United States. This basin contains natural wilderness areas, national parks, and thousands of lakes that bring outdoor enthusiasts from around the world for hunting, fishing, backpacking, boating, and other forms of recreation. However, trade, commerce, visitors, and wildlife can inadvertently transport hitchhiking exotic invasive species that affect the functioning of natural systems by displacing native organisms, introducing diseases, and modifying predator/prey relations. In cooperation with the International Joint Commission, the U.S. Geological Survey evaluated the aquatic invasive species that pose a possible threat to North America. The outcome of this project is a set of lists of invasive species that have traits amenable or proximity to the Rainy-Lake of the Woods Basin. These lists can be referenced to further evaluate known and potential nonindigenous invasive species. The lists were derived by evaluating more than 1,500 species from several online sources including Non-Indigenous Aquatic Species, Great Lakes Aquatic Nonindigenous Species Information System, Biodiversity Information Serving Our Nation, and other State, Provincial, and Federal lists in the United States and Canada. The purpose of these lists is to be a coarse filter to determine which species pose the greatest risk to the Rainy-Lake of the Woods Basin. Using this filter, seven categories of risk assessment priorities were developed: Very High-Approaching, Very High-Present, High-Approaching, High-Present, Moderate, Low, and Native. These categories can be used by the International Rainy-Lake of the Woods Multi-Agency Arrangement Aquatic Invasive Species Subcommittee to prioritize which species will be evaluated further focusing on five risk factors: arrival risk, vulnerability assessment, ecological impact, socioeconomic impact, and beneficial impact. Based on proximity, ease of transport or introduction, and known impact to Rainy-Lake of the Woods or other impacted ecosystems, this project identified the following 10 species that could be prioritized first for risk evaluations: Bythotrephes longimanus (spiny waterflea), Faxonius rusticus (rusty crayfish), Neogobius melanostomus (round goby), Dreissena polymorpha (zebra mussel), Bithynia tentaculata (mud Bithynia or faucet snail), Potamopyrgus antipodarum (New Zealand mud snail), Butomus umbellatus (flowering rush), Nitellopsis obtusa (starry stonewort), Myriophyllum spicatum (Eurasian watermilfoil), and Phragmites australis australis (common reed).

Open-File Report↗
USGS2013

Conformance testing for the spatial data transfer standard

The Spatial Data Transfer Standard (SDTS) was approved as Federal Information Processing Standard (FIPS) 173, effective February 1993. Federal agencies and geographic information system vendors currently are developing SDTS encoding and decoding capabilities. A program is being developed to test encoders and decoders for conformance to the requirements of SDTS profiles. A series of test points will specify SDTS requirements that can be tested by software or by nonautomated methods. By certifying SDTS products, the conformance testing program will benefit both vendors and users of the SDTS.

Cartography and Geographic Information Systems↗
USGS2016

Digital geologic map data for the Ozark National Scenic Riverways and adjacent areas along the Current River and Jacks Fork, Missouri

The geology of the Ozark National Scenic Riverways (ONSR) in southern Missouri has been mapped at 1:24,000 scale. This endeavor was achieved through the combined efforts of U.S. Geological Survey and Missouri Geological Survey individual quadrangle mapping and additional fieldwork by the authors of this report. Geologic data covering the area of the ONSR and a 1-mile (1.6-kilometer) buffer zone surrounding the park, as well as geologic data from a few key adjoining areas, have been compiled into a single, seamless geographic information system database. The intent is to provide base geologic information for natural science research and land management in the park and surrounding areas. The data are served online at ScienceBase ( https://www.sciencebase.gov/catalog/ ), where they are provided in Environmental Systems Research Institute (ESRI) file geodatabase format, and are accompanied by metadata files. These data can be accessed at: http://dx.doi.org/10.5066/F7CJ8BKB . Additional detailed geologic information about the ONSR and surrounding areas is available in the separate 1:24,000-scale quadrangle maps and in a 1:100,000-scale map and report on the regional geology.

Missouri↗
USGS1991

Monitoring grasshopper and locust habitats in Sahelian Africa using GIS and remote sensing technology

Development programmes in Sahelian Africa are beginning to use geographic information system (GIS) technology. One of the GIS and remote sensing programmes introduced to the region in the late 1980s was the use of seasonal vegetation maps made from satellite data to support grasshopper and locust control. Following serious outbreaks of these pests in 1987, the programme addressed a critical need, by national and international crop protection organizations, to monitor site-specific dynamic vegetation conditions associated with grasshopper and locust breeding. The primary products used in assessing vegetation conditions were vegetation index (greenness) image maps derived from National Oceanic and Atmospheric Administration satellite imagery. Vegetation index data were integrated in a GIS with digital cartographic data of individual Sahelian countries. These near-real-time image maps were used regularly in 10 countries for locating potential grasshopper and locust habitats. The programme to monitor vegetation conditions is currently being institutionalized in the Sahel.

International Journal of Geographical Information ↗
USGS2004

Summary of available state ambient stream-water-quality data, 1990-98, and limitations for national assessment

The investigation described in this report summarized data from State ambient stream-water-quality monitoring sites for 10 water-quality constituents or measurements (suspended solids, fecal coliform bacteria, ammonia as nitrogen, nitrite plus nitrate as nitrogen, total phosphorus, total arsenic, dissolved solids, chloride, sulfate, and pH). These 10 water-quality constituents or measurements commonly are listed nationally as major contributors to degradation of surface water. Water-quality data were limited to that electronically accessible from the U.S. Environmental Protection Agency Storage and Retrieval System (STORET), the U.S. Geological Survey National Water Information System (NWIS), or individual State databases. Forty-two States had ambient stream-water-quality data electronically accessible for some or all of the constituents or measurements summarized during this investigation. Ambient in this report refers to data collected for the purpose of evaluating stream ecosystems in relation to human health, environmental and ecological conditions, and designated uses. Generally, data were from monitoring sites assessed for State 305(b) reports. Comparisons of monitoring data among States are problematic for several reasons, including differences in the basic spatial design of monitoring networks; water-quality constituents for which samples are analyzed; water-quality criteria to which constituent concentrations are compared; quantity and comprehensiveness of water-quality data; sample collection, processing, and handling; analytical methods; temporal variability in sample collection; and quality-assurance practices. Large differences among the States in number of monitoring sites precluded a general assumption that statewide water-quality conditions were represented by data from these sites. Furthermore, data from individual monitoring sites may not represent water-quality conditions at the sites because sampling conditions and protocols are unknown. Because of these factors, a high level of uncertainty exists in a national assessment of water quality. The purpose of this report is to present a summary of electronically available State ambient stream-water-quality data for 10 selected constituents and measurements from monitoring sites with nine or more analyses for 199098 and to discuss limitations for use of the data for national assessment. These analyses were statistiscally summarized by monitoring site and State, and the results presented in tabular format. Most of the selected constituents or measurements have U.S. Environmental Protection Agency criteria or guidelines for aquatic-life or drinking-water purposes. A significant finding of this investigation is that for a large percentage of monitoring sites in the Nation, there are insufficient data to meet U.S. Environmental Protection Agency recommendations for determining if water-quality conditions are degraded and for making informed decisions regarding total maximum daily loads.

Water-Resources Investigations Report↗