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At least 415 records · Page 23Linked to original sources
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↗
USGS2009

The National Map customer requirements: Findings from interviews and surveys

The purpose of this study was to receive customer feedback and to understand data and information requirements for The National Map. This report provides results and findings from interviews and surveys and will guide policy and operations decisions about data and information requirements leading to the development of a 5-year strategic plan for the National Geospatial Program. These findings are based on feedback from approximately 2,200 customers between February and August 2008. The U.S. Geological Survey (USGS) conducted more than 160 interviews with 200 individuals. The American Society for Photogrammetry and Remote Sensing (ASPRS) and the International Map Trade Association (IMTA) surveyed their memberships and received feedback from over 400 members. The Environmental Systems Research Institute (ESRI) received feedback from over 1,600 of its U.S.-based software users through an online survey sent to customers attending the ESRI International User Conference in the summer of 2008. The results of these surveys were shared with the USGS and have been included in this report.

Open-File Report↗
USGS2010

Land-cover change in the Ozark Highlands, 1973-2000

Led by the Geographic Analysis and Monitoring Program of the U.S. Geological Survey (USGS) in collaboration with the U.S. Environmental Protection Agency (EPA) and the National Aeronautics and Space Administration (NASA), the Land-Cover Trends Project was initiated in 1999 and aims to document the types, geographic distributions, and rates of land-cover change on a region by region basis for the conterminous United States, and to determine some of the key drivers and consequences of the change (Loveland and others, 2002). For 1973, 1980, 1986, 1992, and 2000 land-cover maps derived from the Landsat series are classified by visual interpretation, inspection of historical aerial photography and ground survey, into 11 land-cover classes. The classes are defined to capture land cover that is discernable in Landsat data. A stratified probability-based sampling methodology undertaken within the 84 Omernik Level III Ecoregions (Omernik, 1987) was used to locate the blocks, with 9 to 48 blocks per ecoregion. The sampling was designed to enable a statistically robust 'scaling up' of the sample-classification data to estimate areal land-cover change within each ecoregion (Loveland and others, 2002; Stehman and others, 2005). At the time of writing, approximately 90 percent of the 84 conterminous United States ecoregions have been processed by the Land-Cover Trends Project. Results from these completed ecoregions illustrate that across the conterminous United States there is no single profile of land-cover/land-use change, rather, there are varying pulses affected by clusters of change agents (Loveland and others, 2002). Land-Cover Trends Project results for the conterminous United States to-date are being used for collaborative environmental change research with partners such as; the National Science Foundation, the National Oceanic and Atmospheric Administration, and the U.S. Fish and Wildlife Service. The strategy has also been adapted for use in a NASA global deforestation initiative, and elements of the project design are being used in the North American Carbon Program's assessment of forest disturbance.

Open-File Report↗
USGS2012

Hydrologic and landscape database for the Cache and White River National Wildlife Refuges and contributing watersheds in Arkansas, Missouri, and Oklahoma

A hydrologic and landscape database was developed by the U.S. Geological Survey, in cooperation with the U.S. Fish and Wildlife Service, for the Cache River and White River National Wildlife Refuges and their contributing watersheds in Arkansas, Missouri, and Oklahoma. The database is composed of a set of ASCII files, Microsoft Access® files, Microsoft Excel® files, an Environmental Systems Research Institute (ESRI) ArcGIS® geodatabase, ESRI ArcGRID® raster datasets, and an ESRI ArcReader® published map. The database was developed as an assessment and evaluation tool to use in examining refuge-specific hydrologic patterns and trends as related to water availability for refuge ecosystems, habitats, and target species; and includes hydrologic time-series data, statistics, and hydroecological metrics that can be used to assess refuge hydrologic conditions and the availability of aquatic and riparian habitat. Landscape data that describe the refuge physiographic setting and the locations of hydrologic-data collection stations are also included in the database. Categories of landscape data include land cover, soil hydrologic characteristics, physiographic features, geographic and hydrographic boundaries, hydrographic features, regional runoff estimates, and gaging-station locations. The database geographic extent covers three hydrologic subregions—the Lower Mississippi–St Francis (0802), the Upper White (1101), and the Lower Arkansas (1111)—within which human activities, climatic variation, and hydrologic processes can potentially affect the hydrologic regime of the refuges and adjacent areas. Database construction has been automated to facilitate periodic updates with new data. The database report (1) serves as a user guide for the database, (2) describes the data-collection, data-reduction, and data-analysis methods used to construct the database, (3) provides a statistical and graphical description of the database, and (4) provides detailed information on the development of analytical techniques designed to assess water availability for ecological needs.

Arkansas;Missouri;Oklahoma↗
USGS1995

Integrating multisource land use and land cover data

As part of the U.S. Geological Survey's (USGS) land use and land cover (LULC) program, the USGS in cooperation with the Environmental Systems Research Institute (ESRI) is collecting and integrating LULC data for a standard USGS 1:100,000-scale product. The LULC data collection techniques include interpreting spectrally clustered Landsat Thematic Mapper (TM) images; interpreting 1-meter resolution digital panchromatic orthophoto images; and, for comparison, aggregating locally available large-scale digital data of urban areas. The area selected is the Vancouver, WA-OR quadrangle, which has a mix of urban, rural agriculture, and forest land. Anticipated products include an integrated LULC prototype data set in a standard classification scheme referenced to the USGS digital line graph (DLG) data of the area and prototype software to develop digital LULC data sets. This project will evaluate a draft standard LULC classification system developed by the USGS for use with various source material and collection techniques. Federal, State, and local governments, and private sector groups will have an opportunity to evaluate the resulting prototype software and data sets and to provide recommendations. It is anticipated that this joint research endeavor will increase future collaboration among interested organizations, public and private, for LULC data collection using common standards and tools.

Open-File Report↗
USGS2004

Map showing geology, oil and gas fields, and geologic provinces of the Caribbean Region

This CD-ROM compilation contains a map and associated spatial data showing surface geology, faults, oil and gas field centerpoints, and geologic provinces of the Caribbean region, draped over a shaded relief image of topography and bathymetry. The map is provided in the Environmental Systems Research Institute, Inc. (ESRI) ArcMap and ArcReader GIS formats, as well as in Adobe Acrobat Portable Document Format (PDF). On this CD-ROM, ESRI ArcReader and Adobe Acrobat Reader software provide a way to view and interact with the maps. The organization and user-friendly navigation of this CD-ROM ensure easy access to its maps and data by using the links on the right side of each page. A link to the USGS World Energy Project website is also provided to access the latest information, updates, and interactive maps, as they relate to this and other world energy products. In addition, system requirements, permission, and contact information can be found in the readme section of this product. Navigation of this product can be fully utilized with most web browsers (Internet Explorer 6.0/Netscape Navigator 7.1 or later recommended). Note: an Internet connection is necessary to view USGS website links, World Energy website, and the Caribbean Internet Map Service.

Open-File Report↗
USGS1998

Land status and federal mineral ownership in the Powder River basin, Wyoming and Montana; a digital data set for geographic information systems

As the Nation's energy resources continue to be examined for development, it is critical that a digital database exist that contains location data for all Federal land and mineral resources. The U.S. Geological Survey (USGS), in cooperation with the Bureau of Land Management (BLM), is collecting these ownership files and compiling them in Environmental Systems Research Institute, Inc. (ESRI) ARC/INFO coverages, to form a standardized data library. A coverage is a digital version of a map in the form of vector data storage. These coverages are combined with models of coal deposits from the USGS National Coal Resource Assessment project, a five-year effort to identify and characterize the coal beds and coal zones that will provide fuel for the Nation’s energy needs during the first quarter of the twenty-first century. Geographic and geologic data layers are integrated in a Geographic Information System (GIS) to answer complex geo-spatial questions concerning coal resource occurrence.

Montana, Wyoming↗
USGS2001

Digital geologic map of the Fawnskin 7.5' quadrangle, San Bernardino County, California

Version 1.1 of this Open-File Report contains a digital geologic map and map database of the Fawnskin 7.5' quadrangle, San Bernardino County, California, that includes: 1. ARC/INFO (Environmental Systems Research Institute) version 7.2.1 double-precision coverages of the various elements of the geologic map 2. A PostScript (.ps) file to plot the geologic map on a topographic base, containing a Correlation of Map Units diagram and a Description of Map Units 3. Portable Document Format (.pdf) files of: a. This Readme; includes in Appendix I, data contained in fskn_met.txt b. The same graphic as plotted in 2 above. (Test plots from this .pdf do not produce 1:24,000-scale maps. Adobe Acrobat page-size settings control map scale.) This release includes features not found in most other digital geologic maps, in that all polygons, lines, and points in the coverage are encoded with detailed, comprehensive geologic data contained in six INFO data tables (.rel). (See Matti and others, 1998a, 1998b, and 1998c, for information on how the encoding may be accessed and utilized.) No paper map is included in the Open-File Report, but a PostScript plot file containing an image of the geologic map sheet, topographic base, Correlation of Map Units (CMU), and detailed Description of Map Units (DMU) is. The Correlation of Map Units and Description of Map Units are in the editorial format of USGS Miscellaneous Investigations Series maps (I-maps) but have not been edited to comply with I-map standards. Within the geologic map data package, map units are identified by such standard geologic-map criteria as formation name, age, and lithology. Even though this is an author-prepared report, every attempt has been made to closely adhere to the stratigraphic nomenclature of the U.S. Geological Survey. Descriptions of units can be obtained by viewing or plotting the .pdf file (3b above) or plotting the PostScript file (2 above). If roads in some areas, especially roads that parallel topographic contours, do not show well on plots of the geologic map, we recommend use of the USGS Fawnskin 7.5' topographic quadrangle in conjunction with the geologic map.

California↗
USGS1999

Regional geologic map of San Andreas and related faults in Carrizo Plain, Temblor, Caliente and La Panza Ranges and vicinity, California: A digital database

This Open-File Report is a digital geologic map database. The report serves to introduce and describe the digital data. There is no paper map included in the Open-File Report. The report includes PostScript and PDF plot files that can be used to plot images of the geologic map sheet and explanation sheet. This digital map database is prepared from a previously published map by Dibblee (1973). The geologic map database delineates map units that are identified by general age, lithology, and clast size following the stratigraphic nomenclature of the U.S. Geological Survey. For descriptions of the units, their stratigraphic relations, and sources of geologic mapping, consult the explanation sheet (of99-14_4b.ps or of99-14_4d.pdf), or the original published paper map (Dibblee, 1973). The scale of the source map limits the spatial resolution (scale) of the database to 1:125,000 or smaller. For those interested in the geology of Carrizo Plain and vicinity who do not use an ARC/INFO compatible Geographic Information System (GIS), but would like to obtain a paper map and explanation, PDF and PostScript plot files containing map images of the data in the digital database, as well as PostScript and PDF plot files of the explanation sheet and explanatory text, have been included in the database package (please see the section 'Digital Plot Files', page 5). The PostScript plot files require a gzip utility to access them. For those without computer capability, we can provide users with the PostScript or PDF files on tape that can be taken to a vendor for plotting. Paper plots can also be ordered directly from the USGS (please see the section 'Obtaining Plots from USGS Open-File Services', page 5). The content and character of the database, methods of obtaining it, and processes of extracting the map database from the tar (tape archive) file are described herein. The map database itself, consisting of six ARC/INFO coverages, can be obtained over the Internet or by magnetic tape copy as described below. The database was compiled using ARC/INFO, a commercial Geographic Information System (Environmental Systems Research Institute, Redlands, California), with version 3.0 of the menu interface ALACARTE (Fitzgibbon and Wentworth, 1991, Fitzgibbon, 1991, Wentworth and Fitzgibbon, 1991). The ARC/INFO coverages are stored in uncompressed ARC export format (ARC/INFO version 7.x). All data files have been compressed, and may be uncompressed with gzip, which is available free of charge over the Internet via links from the USGS Public Domain Software page (http://edcwww.cr.usgs.gov/doc/edchome/ndcdb/public.html). ARC/INFO export files (files with the .e00 extension) can be converted into ARC/INFO coverages in ARC/INFO (see below) and can be read by some other Geographic Information Systems, such as MapInfo via ArcLink and ESRI's ArcView.

California↗
USGS2017

Bedrock and structural geologic maps of eastern Candor Sulci, western Ceti Mensa, and southeastern Ceti Mensa, Candor Chasma, Valles Marineris region of Mars

This map product contains a set of three 1:18,000-scale maps showing the geology and structure of study areas in the western Candor Chasma region of Valles Marineris, Mars. These maps are part of an informal series of large-scale maps and map-based topical studies aimed at refining current understanding of the geologic history of western Candor Chasma. The map bases consist of digital elevation models and orthorectified images derived from High Resolution Imaging Science Experiment (HiRISE) data. These maps are accompanied by geologic cross sections, colorized elevation maps, and cutouts of HiRISE images showing key superposition relations. Also included in this product is a Correlation of Map Units that integrates units across all three map areas, as well as an integrated Description of Map Units and an integrated Explanation of Map Symbols. The maps were assembled using ArcGIS software produced by Environmental Systems Research Institute (http://www.esri.com). The ArcGIS projects and databases associated with each map are included online as supplemental data.

Scientific Investigations Map↗
USGS2018

Geologic map of the Nepenthes Planum Region, Mars

This map product contains a map sheet at 1:1,506,000 scale that shows the geology of the Nepenthes Planum region of Mars, which is located between the cratered highlands that dominate the southern hemisphere and the less-cratered sedimentary plains that dominate the northern hemisphere. The map region contains cone- and mound-shaped landforms as well as lobate materials that are morphologically similar to terrestrial igneous or mud vents and flows. This map is part of an informal series of small-scale (large-area) maps aimed at refining current understanding of the geologic units and structures that make up the highland-to-lowland transition zone. The map base consists of a controlled Thermal Emission Imaging System (THEMIS) daytime infrared image mosaic (100 meters per pixel resolution) supplemented by a Mars Orbiter Laser Altimeter (MOLA) digital elevation model (463 meters per pixel resolution). The map includes a Description of Map Units and a Correlation of Map Units that describes and correlates units identified across the entire map region. The geologic map was assembled using ArcGIS software by Environmental Systems Research Institute ( http://www.esri.com ). The ArcGIS project, geodatabase, base map, and all map components are included online as supplemental data.

Scientific Investigations Map↗
USGS2006

Proceedings of the U.S. Geological Survey Sixth Biennial Geographic Information Science Workshop, Denver, Colorado, April 24-28, 2006

The U.S. Geological Survey's (USGS) Sixth Biennial Geographic Information Science Workshop April 24 - 28, 2006, at the Denver Federal Center in Denver, Colorado, provides a unique opportunity for multi-disciplinary Geographic Information Systems (GIS) and associated scientific professionals to share, learn, present, and discuss a wide variety of geospatial-related topics. Information is exchanged through a series of plenary sessions, hands-on technical workshops, user and commercial vendor demonstrations, lecture and poster sessions, and specialty meetings. Workshop attendance is limited to Department of Interior (DOI) and USGS employees and contractors; however, plenary, hands-on, and lecture sessions have presenters from other Federal agencies, numerous commercial vendors, universities, and several consortia. Over 175 participants are expected to attend the Workshop. Several prominent speakers are featured at this Workshop. Monday evening Star Guest Speaker and National Aeronautics and Space Administration (NASA) Astronaut Captain Dominic Gorie will talk about his experiences as a veteran of three space flights and over 32 days in space, including the NASA Space Shuttle Radar Topography Mission that mapped more than 47 million miles of the Earth's land surface. Selected as an astronaut candidate by NASA in December 1994, Captain Gorie is currently Chief of the Astronaut Shuttle Branch. Monday evening also features a town hall meeting with Geographic Information Office (GIO) leaders Karen Siderelis, Kevin Gallagher, Bob Pierce, Steve Guptill, Mark DeMulder, John Mahoney, and Mark Negri, who will discuss changes and activities within the GIO in an open discussion format. Tuesday plenary sessions feature keynote speaker Dr. P. Patrick Leahy, Acting USGS Director. Dr. Leahy holds undergraduate and graduate degrees in geology (1968) and geophysics (1970) from Boston College. In 1979, he received his doctorate in geology from Rensselaer Polytechnic Institute, where he specialized in regional ground-water studies and hydraulics. Dr. Leahy has been with the USGS since 1974, and has held various technical and managerial positions, including Associate Director for Geology and Chief of the National Water-Quality Assessment (NAWQA) Program. Dr. Leahy will be discussing a broad range of topics including Bureau accomplishments, initiatives, and budgets. The purpose of this proceedings volume is to serve as an activity reference for Workshop attendees as well as an archive of technical abstracts submitted, presented, and discussed at the Workshop. Author, co-author, and presenter names, affiliations, and contact information are listed with presentation titles along with submitted abstracts. Some hands-on sessions are offered twice. In these instances, abstracts submitted for publication are presented in the proceedings on both days they are offered. All acronyms used in these proceedings are explained in the text of each abstract. The term 'ArcGIS' refers to an integrated collection of GIS software products produced by Environmental Systems Research Institute, Inc. (ESRI).

Scientific Investigations Report↗
USGS2008

Multiple Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California

With the exception of Los Angeles, perhaps no urban area in the United States is more at risk from landsliding, triggered by either precipitation or earthquake, than the San Francisco Bay region of northern California. By January each year, seasonal winter storms usually bring moisture levels of San Francisco Bay region hillsides to the point of saturation, after which additional heavy rainfall may induce landslides of various types and levels of severity. In addition, movement at any time along one of several active faults in the area may generate an earthquake large enough to trigger landslides. The danger to life and property rises each year as local populations continue to expand and more hillsides are graded for development of residential housing and its supporting infrastructure. The chapters in the text consist of: *Introduction by Russell W. Graymer *Chapter 1 Rainfall Thresholds for Landslide Activity, San Francisco Bay Region, Northern California by Raymond C. Wilson *Chapter 2 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike and Steven Sobieszczyk *Chapter 3 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Chapter 4 Landslide Hazard Modeled for the Cities of Oakland, Piedmont, and Berkeley, Northern California, from a M=7.1 Scenario Earthquake on the Hayward Fault Zone by Scott B. Miles and David K. Keefer *Chapter 5 Synthesis of Landslide-Hazard Scenarios Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike The plates consist of: *Plate 1 Susceptibility to Deep-Seated Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Richard J. Pike, Russell W. Graymer, Sebastian Roberts, Naomi B. Kalman, and Steven Sobieszczyk *Plate 2 Susceptibility to Shallow Landsliding Modeled for the Oakland-Berkeley Area, Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Plate 3 Susceptibility to Shallow Landsliding Modeled for the Cities of Oakland and Piedmont Northern California by Kevin M. Schmidt and Steven Sobieszczyk *Plate 4 Seismic Landslide Hazard Modeled for the Cities of Oakland, Piedmont, and Berkeley, Northern California by Scott B. Miles and David K. Keefer III The relative hazard for each of several landslide scenarios is presented as a geospatial database. This publication includes ARC/INFO (Environmental Systems Research Institute, http://www.esri.com) version 8.1.2 grids and associated tables and four text files of FGDC-compliant metadata for each grid.

Scientific Investigations Report↗
USGS2009

Methodology for Estimation of Flood Magnitude and Frequency for New Jersey Streams

Methodologies were developed for estimating flood magnitudes at the 2-, 5-, 10-, 25-, 50-, 100-, and 500-year recurrence intervals for unregulated or slightly regulated streams in New Jersey. Regression equations that incorporate basin characteristics were developed to estimate flood magnitude and frequency for streams throughout the State by use of a generalized least squares regression analysis. Relations between flood-frequency estimates based on streamflow-gaging-station discharge and basin characteristics were determined by multiple regression analysis, and weighted by effective years of record. The State was divided into five hydrologically similar regions to refine the regression equations. The regression analysis indicated that flood discharge, as determined by the streamflow-gaging-station annual peak flows, is related to the drainage area, main channel slope, percentage of lake and wetland areas in the basin, population density, and the flood-frequency region, at the 95-percent confidence level. The standard errors of estimate for the various recurrence-interval floods ranged from 48.1 to 62.7 percent. Annual-maximum peak flows observed at streamflow-gaging stations through water year 2007 and basin characteristics determined using geographic information system techniques for 254 streamflow-gaging stations were used for the regression analysis. Drainage areas of the streamflow-gaging stations range from 0.18 to 779 mi2. Peak-flow data and basin characteristics for 191 streamflow-gaging stations located in New Jersey were used, along with peak-flow data for stations located in adjoining States, including 25 stations in Pennsylvania, 17 stations in New York, 16 stations in Delaware, and 5 stations in Maryland. Streamflow records for selected stations outside of New Jersey were included in the present study because hydrologic, physiographic, and geologic boundaries commonly extend beyond political boundaries. The StreamStats web application was developed cooperatively by the U.S. Geological Survey and the Environmental Systems Research Institute, Inc., and was designed for national implementation. This web application has been recently implemented for use in New Jersey. This program used in conjunction with a geographic information system provides the computation of values for selected basin characteristics, estimates of flood magnitudes and frequencies, and statistics for stream locations in New Jersey chosen by the user, whether the site is gaged or ungaged.

Scientific Investigations Report↗
USGS2009

Estimating Prediction Uncertainty from Geographical Information System Raster Processing: A User's Manual for the Raster Error Propagation Tool (REPTool)

The U.S. Geological Survey Raster Error Propagation Tool (REPTool) is a custom tool for use with the Environmental System Research Institute (ESRI) ArcGIS Desktop application to estimate error propagation and prediction uncertainty in raster processing operations and geospatial modeling. REPTool is designed to introduce concepts of error and uncertainty in geospatial data and modeling and provide users of ArcGIS Desktop a geoprocessing tool and methodology to consider how error affects geospatial model output. Similar to other geoprocessing tools available in ArcGIS Desktop, REPTool can be run from a dialog window, from the ArcMap command line, or from a Python script. REPTool consists of public-domain, Python-based packages that implement Latin Hypercube Sampling within a probabilistic framework to track error propagation in geospatial models and quantitatively estimate the uncertainty of the model output. Users may specify error for each input raster or model coefficient represented in the geospatial model. The error for the input rasters may be specified as either spatially invariant or spatially variable across the spatial domain. Users may specify model output as a distribution of uncertainty for each raster cell. REPTool uses the Relative Variance Contribution method to quantify the relative error contribution from the two primary components in the geospatial model - errors in the model input data and coefficients of the model variables. REPTool is appropriate for many types of geospatial processing operations, modeling applications, and related research questions, including applications that consider spatially invariant or spatially variable error in geospatial data.

Techniques and Methods↗
USGS2005

Middle Mississippi River decision support system: user's manual

This user's manual describes the Middle Mississippi River Decision Support System (MMRDSS) and gives detailed examples on its use. The MMRDSS provides a framework to assist decision makers regarding natural resource issues in the Middle Mississippi River floodplain. The MMRDSS is designed to provide users with a spatially explicit tool for tasks, such as inventorying existing knowledge, developing models to investigate the potential effects of management decisions, generating hypotheses to advance scientific understanding, and developing scientifically defensible studies and monitoring. The MMRDSS also includes advanced tools to assist users in evaluating differences in complexity, connectivity, and structure of aquatic habitats among river reaches. The Environmental Systems Research Institute ArcView 3.x platform was used to create and package the data and tools of the MMRDSS.

Techniques and Methods↗
USGS2011

Quantifying seascape structure: Extending terrestrial spatial pattern metrics to the marine realm

Spatial pattern metrics have routinely been applied to characterize and quantify structural features of terrestrial landscapes and have demonstrated great utility in landscape ecology and conservation planning. The important role of spatial structure in ecology and management is now commonly recognized, and recent advances in marine remote sensing technology have facilitated the application of spatial pattern metrics to the marine environment. However, it is not yet clear whether concepts, metrics, and statistical techniques developed for terrestrial ecosystems are relevant for marine species and seascapes. To address this gap in our knowledge, we reviewed, synthesized, and evaluated the utility and application of spatial pattern metrics in the marine science literature over the past 30 yr (1980 to 2010). In total, 23 studies characterized seascape structure, of which 17 quantified spatial patterns using a 2-dimensional patch-mosaic model and 5 used a continuously varying 3-dimensional surface model. Most seascape studies followed terrestrial-based studies in their search for ecological patterns and applied or modified existing metrics. Only 1 truly unique metric was found (hydrodynamic aperture applied to Pacific atolls). While there are still relatively few studies using spatial pattern metrics in the marine environment, they have suffered from similar misuse as reported for terrestrial studies, such as the lack of a priori considerations or the problem of collinearity between metrics. Spatial pattern metrics offer great potential for ecological research and environmental management in marine systems, and future studies should focus on (1) the dynamic boundary between the land and sea; (2) quantifying 3-dimensional spatial patterns; and (3) assessing and monitoring seascape change.

Marine Ecology Progress Series↗
USGS2018

Selenium, mercury, and their molar ratios in sportfishes from drinking water reservoirs

Mercury (Hg) bioaccumulates in aquatic ecosystems and may pose a risk to humans who consume fish. Selenium (Se) has the ability to reduce Hg toxicity, but the current guidance for human consumption of fish is based on Hg concentration alone. The purpose of the present study was to examine the relationship between Se and Hg in freshwater sportfish, for which there is a paucity of existing data. We collected three species of fish from different trophic positions from two drinking water reservoirs in central North Carolina, USA, to assess Hg and Se concentrations in relation to fish total length and to compare two measures of the protective ability of Se, the Se:Hg molar ratio and Se health benefit value (HBV Se ), to current guidance for Hg. According to the Se:Hg molar ratio, all of the low trophic position fish sampled and the middle trophic position fish sampled from one of the reservoirs were safe for consumption. The same number of fish were considered safe using the HBV Se . More fish were deemed unsafe when using the Se:Hg molar ratio and HBV Se than were considered unsafe when using the U.S. Environmental Protection Agency (USEPA) Hg threshold. These findings suggest that the measures of Se protection may be unnecessarily conservative or that the USEPA Hg threshold may not be sufficiently protective of human health, especially the health of sensitive populations like pregnant or nursing mothers and young children. Future examination of the Se:Hg molar ratio and HBV Se from a variety of fish tissue samples would help refine the accuracy of these measures so that they may be appropriately utilized in ecological and human health risk assessment.

International Journal of Environmental Research an↗