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At least 289 records · Page 16Linked to original sources
USGS2010

A method for land surveying sampling optimization strategy

At present, how to select a limited but representative sample dataset from the existing land information database to guide the new round of land survey and assessment sampling is a critical issue for land sampling strategy study. As a case study to determine and analyze the sample capacity and sample spatial location of land survey sampling for the study area, Panyu District in Guangzhou, the paper developed the strategy based on the combination of classical sampling technique and geographical model under a certain confidence level and estimation accuracy requirement, and the performance of the sampling strategy was then evaluated by the Global Geary's C and the Quick-BP neural network model respectively. The test result showed that, compared with traditional c-means clustering sampling method, the accuracy of the sampling prediction based on local Moran index spatial clustering sampling method was increased by 13.57% which abstracted better the land information in the database.

Guangzhou↗
USGS2003

The challenge of archiving and preserving remotely sensed data

Few would question the need to archive the scientific and technical (S&T) data generated by researchers. At a minimum, the data are needed for change analysis. Likewise, most people would value efforts to ensure the preservation of the archived S&T data. Future generations will use analysis techniques not even considered today. Until recently, archiving and preserving these data were usually accomplished within existing infrastructures and budgets. As the volume of archived data increases, however, organizations charged with archiving S&T data will be increasingly challenged (U.S. General Accounting Office, 2002). The U.S. Geological Survey has had experience in this area and has developed strategies to deal with the mountain of land remote sensing data currently being managed and the tidal wave of expected new data. The Agency has dealt with archiving issues, such as selection criteria, purging, advisory panels, and data access, and has met with preservation challenges involving photographic and digital media. That experience has allowed the USGS to develop management approaches, which this paper outlines.

Data Science Journal↗
USGS1999

Environmental issues associated with fossil fuel resources; an evaluation of research opportunities for the U.S. Geological Survey's Energy Resources Program

Fossil fuel consumption in the United States has nearly tripled within the last 50 years (fig. 1), and is expected to continue increasing. As our knowledge and awareness of environmental consequences related to fossil fuel extraction and use grow, we as a nation, face the challenge of balancing our energy requirements with a desire for environmentally cleaner fuel. To help meet this challenge, the Energy Resources Program (ERP) of the Geologic Division (GD), U.S. Geological Survey (USGS) sponsored three internal workshops and a World Wide Web (WWW) workshop. The primary goal of these workshops was to identify those environmental issues that are related to fossil fuels, are national in scope, and are within the purview of the USGS as an earth-science government agency. Those issues so identified will be prioritized according to ERP's future research plan and according to the extent they provide an environmental framework for ERP's petroleum and coal assessments. The purpose of this paper is to provide the results of the internal and WWW workshops as proposed topics of research for future ERP work, delineate studies to answer the questions related to each proposed research area, and link the studies to the seven science goals of the Geologic Division. The information provided herein will be used in preparing the USGS Geologic Division's FY2000 prospectus and ERP's next five-year strategic plan. Acknowledgements. The authors wish to acknowledge information on ERP environmental projects provided by Les Magoon, Paul Lillis, Keith Kvenvolden, Tom Lorenson, and Bob Rosenbauer. Peter Schweitzer was instrumental in providing the software for the WWW workshop, Cheryl Adkisson for constructing the workshop web pages, and Laura Friedrich for constructing the web pages summarizing the internal workshops. Stan Mroczkowski, Jim Otton, Donna Read, and Dorothy Tanti provided notes of or logistical assistance for the internal workshops. This report reflects the collective input of numerous USGS managers and scientists their participation in the workshops is greatly appreciated.

Open-File Report↗
USGS2017

Using science to inform management and improve biological conservation in the Desert Renewable Energy Conservation Plan

The Mojave and Colorado deserts of southern California have been viewed as vast wilderness since early exploration and, until recently, were considered the most untrammeled among western landscapes in the contiguous lower 48 states (United States Department of Agriculture 1893; Leu et al. 2008). However, the factors that define desert wilderness—small human population, temperature differentials that create unrelenting winds, low rainfall, and cloudless skies—are attractive for renewable energy development. The demand for clean, renewable energy is a national and regional priority and has increased demand for large-scale solar and wind farms in the deserts, particularly in California. The need to balance these national and state energy priorities with existing natural resource and land conservation policies has emerged as a landscape-scale land-use planning initiative known as the Desert Renewable Energy Conservation Plan (DRECP). One of the primary goals for the DRECP was to establish Development Focus Areas (DFAs) where high-quality renewable energy potential of up to 20 gigawatts (GW) could be implemented by the year 2040. DFAs were designed to provide expedited project approvals in locations where environmental impacts could be managed and mitigated, and proximity to transmission corridors provides for the efficient dissemination of energy to users. The DRECP also aims to identify protections for natural resources, recreation, and cultural resources. This plan identifies 37 covered species that receive special consideration in the DRECP. Among the special considerations are climate adaptation requirements, such as the ability to maintain population connectivity through wildlife corridors, while protecting several special recreation areas and 32,000 known cultural sites that are dispersed throughout the region. We evaluated several particular aspects of the DRECP design and process. In particular, we examined land designations in relation to published studies on Mohave ground squirrel (Xerospermophilus mohavensis) habitat and genetic diversity patterns of a suite of broadly distributed desert animal species. The squirrel and its habitat are of particular interest because the entire range of the squirrel is encompassed by the DRECP. We describe the framework of the DRECP, provide a case study of how the DRECP accommodates the needs of the Mohave ground squirrel and its habitat, illustrate DFAs in relation to the genetic diversity of a broad range of terrestrial biota, and conclude with some observations on how land-use issues were resolved across the landscape under various scenarios.

Conference Paper↗
USGS2020

Alaska North Slope 2018 Hydrate-01 Stratigraphic Test Well: Technical results

The Hydrate-01 Stratigraphic Test Well was drilled in December 2018 to confirm that a seismically-identified location within the western Prudhoe Bay Unit might be suitable for extended-duration scientific production testing. The well tested two primary targets: the deeper Unit B is highly favorable due to optimal reservoir temperature and minimal observed risk for direct communication with permeable, hydrate-free water-bearing zones. The shallower Unit D provides a secondary target and opportunity to assess additional scientific and operational issues.

Alaska↗
USGS2013

Modeling rain-fed maize vulnerability to droughts using the standardized precipitation index from satellite estimated rainfall—Southern Malawi case study

During 1990s, disaster risk reduction emerged as a novel, proactive approach to managing risks from natural hazards. The World Bank, USAID, and other international donor agencies began making efforts to mainstream disaster risk reduction in countries whose population and economies were heavily dependent on rain-fed agriculture. This approach has more significance in light of the increasing climatic hazard patterns and the climate scenarios projected for different hazard prone countries in the world. The Famine Early Warning System Network (FEWS NET) has been monitoring the food security issues in the sub-Saharan Africa, Asia and in Haiti. FEWS NET monitors the rainfall and moisture availability conditions with the help of NOAA RFE2 data for deriving food security status in Africa. This paper highlights the efforts in using satellite estimated rainfall inputs to develop drought vulnerability models in the drought prone areas in Malawi. The satellite RFE2 based SPI corresponding to the critical tasseling and silking phases (in the months of January, February, and March) were statistically regressed with drought-induced yield losses at the district level. The analysis has shown that the drought conditions in February and early March lead to most damage to maize yields in this region. The district-wise vulnerabilities to drought were upscaled to obtain a regional maize vulnerability model for southern Malawi. The results would help in establishing an early monitoring mechanism for drought impact assessment, give the decision makers additional time to assess seasonal outcomes, and identify potential food-related hazards in Malawi.

International Journal of Disaster Risk Reduction↗
USGS2007

Proceedings of the Fourth Glacier Bay Science Symposium

Foreword Glacier Bay was established as a National Monument in 1925, in part to protect its unique character and natural beauty, but also to create a natural laboratory to examine evolution of the glacial landscape. Today, Glacier Bay National Park and Preserve is still a place of profound natural beauty and dynamic landscapes. It also remains a focal point for scientific research and includes continuing observations begun decades ago of glacial processes and terrestrial ecosystems. In recent years, research has focused on glacial-marine interactions and ecosystem processes that occur below the surface of the bay. In October 2004, Glacier Bay National Park convened the fourth in a series of science symposiums to provide an opportunity for researchers, managers, interpreters, educators, students and the general public to share knowledge about Glacier Bay. The Fourth Glacier Bay Science Symposium was held in Juneau, Alaska, rather than at the Park, reflecting a desire to maximize attendance and communication among a growing and diverse number of stakeholders interested in science in the park. More than 400 people attended the symposium. Participants provided 46 oral presentations and 41 posters covering a wide array of disciplines including geology, glaciology, oceanography, wildlife and fisheries biology, terrestrial and marine ecology, socio-cultural research and management issues. A panel discussion focused on the importance of connectivity in Glacier Bay research, and keynote speakers (Gary Davis and Terry Chapin) spoke of long-term monitoring and ecological processes. These proceedings include 56 papers from the symposium. A summary of the Glacier Bay Science Plan-itself a subject of a meeting during the symposium and the result of ongoing discussions between scientists and resource managers-also is provided. We hope these proceedings illustrate the diversity of completed and ongoing scientific studies, conducted within the Park. To this end, we invited all presenters to submit brief technical summaries of their work, to capture the gist of their study and its main findings without an overload of details and methodology. We also asked authors to include a few words on the management implications of their work to help bridge the gap between scientists and managers in understanding how specific research questions may translate to management practice. Papers in this volume are laid out by subject matter, from terrestrial and freshwater subjects to glacial-marine geology, to the ecology of marine animals and ending with risk assessment, human impacts and science-management considerations. In summary, we hope the proceedings will serve as a useful reference to completed and ongoing studies in Glacier Bay National Park, and thereby provide park enthusiasts, scientists, and managers with a road map of scientific progress.

Scientific Investigations Report↗
USGS1955

U.S. Geological Survey Trace Elements and related reports through 1954

This report supersedes TEI-400, "U.S. Geological Survey Trace Elements and related reports through 1953." Part I is a numerical list of U.S. Geological Survey Trace Elements Investigations and Memorandum reports. This part lists not only reports (followed by a date) that have been transmitted to the U.S> Atomic Energy Commission, but also reports in preparation (followed by an asterisk) for which tentative titles were available on December 31, 1954. If a report, or portion of a report, has been published, the fact is indicated by the abbreviation of the medium of publication. (See also Part II.) Part II is a reference guide to Trace Elements and related reports that are available to the public (this part supersedes Part I of Bulletin 1019-B). These reports are grouped according to the type of publication or release. If a report, or portion of the report, has been published in more than one form, appropriate cross-references are given to indicate the other forms of publication. Abstracts published in Nuclear Science Abstracts are not included in Part II; however, if the abstract of a Trace Elements report has been published in NSA, the fact is indicated in Part I. Publications in process on December 31, 1954, are designated by an asterisk. Part III is a finding list of states, areas, and subjects and supersedes Part II of Bulletin 1019-B. It is based on information derived mostly from the titles of reports and, where titles are of general nature, from a cursory review of the reports. This list is not a complete index of the information given in Trace Elements and related reports, but is designed to find subjects of major interest, Because of the numerous entries for Colorado and Utah, information has been listed by counties and, where possible, by subject under these states. Other states have county listings only if a county is included in the title of a report; otherwise, area may be listed separately under the state. Major subjects are listed separately in the index and also, where appropriate under states. Analytical methods and subjects related to analytical research are listed under Analytical Methods and Research, but not separately throughout the index. Most mineralogic studies are included under the heading Mineralogy, but are not necessarily listed according to location. Part IV is an author index. The words “with” and “and” are used to indicate seniority of authorship. For example, a listing of Smith and Brown indicated that Smith is the senior author. A listing of Smith with Brown indicates that Brown is the senior author. In both parts III and IV all Trace Elements reports are listed, as well as other related reports that have not been issued as Trace Elements reports. The following abbreviations have been used: TEI, Trace Elements Investigations report; TEM, Trace Elements Memorandum report; OF, open file; TIS, Technical Information Service release; C, Circular; B, Bulletin; P, Professional Paper; MC, Maps and Charts; J, Journal; and NSA, Nuclear Science Abstracts.

Trace Elements Investigations↗
USGS1986

Changing landscapes and the cosmopolitism of the eastern Colorado avifauna

The avifauna of continental North America has changed dramatically since colonial times. Excessive hunting contributed, at least in part, to the extinction of birds such as the great auk ( Pinguinus impennis ) and passenger pigeon ( Ectopistes migratorius ), while more recently organochlorine insecticide residues have resulted in drastic reductions in numbers of brown pelicans ( Pelecanus occidentalis ) (Anderson et al. 1975) and other species. Generally, however, vertebrate populations change in direct response to changes in their habitats. For example, herring gulls ( Larus argentatus ) have increased in numners (Kadlec and Drury 1968) with urbanization of the New England coastline, in the same locations formerly occupied by the extinct heath hen ( Tympanuchus cupido cupido ). Also, passerine birds of forest interiors have declined in numbers with fragmentation of the eastern deciduous forest into small stands; this fragmentation has led to increases in numbers of edge species (Robbins 1979, Ambuel and Temple 1983). Even subtle community shifts can introduce new competitive processes that can augment population changes among species (Brittingham and Temple 1983). Such studies of broad-scale changes in vegetative communities and their influence on native wildlife species have fostered the recent topical emphasis on "conservation biology" (Soule and Wilcox 1980, Soule 1985) and "landscape ecology" (Burgess and Sharpe 1981, Harris 1984:25-43). As changes in landscapes are causing subtle (but potentially dramatic) changes in the distribution of native species, conservation biologists are finding that mere presence-absence data on populations, or even accurate information on reproductive success, is inadequate to evaluate management activities or environmental perturbations. The principles of "conservation genetics" are attracting interest in the management of natural preserves especially (Schonewald-Cox et al. 1983). Changing patterns in landscape complexion or genetic makeup of a population are difficult to detect locally. Contemporary issues in the conservation of native species demand regional and continental perspectives (Samson and Knopf 1982). Thus, management activities at specific sites are often viewed as short-sighted by planners and conservation critics. This paper illustrates how these contemporary theories can influence a local conservation perspective. That perspective is developed around historical processes that have led to cosmopolitism of the local avifauna on the Colorado Division of Wildlife's South Platte Wildlife Management Area (SPWMA) near Crook, Colorado.

Colorado↗
USGS2014

Taking the mystery out of mathematical model applications to karst aquifers—A primer

Advances in mathematical model applications toward the understanding of the complex flow, characterization, and water-supply management issues for karst aquifers have occurred in recent years. Different types of mathematical models can be applied successfully if appropriate information is available and the problems are adequately identified. The mathematical approaches discussed in this paper are divided into three major categories: 1) distributed parameter models, 2) lumped parameter models, and 3) fitting models. The modeling approaches are described conceptually with examples (but without equations) to help non-mathematicians understand the applications.

Conference Paper↗
USGS1966

U.S. Federal research on fisheries and limnology in the Great Lakes through 1964: an annotated bibliography

The annotated bibliography is preceded by a brief account of the Federal research program in fisheries and limnology in the Great Lakes in 1957-64. The bibliography covers 314 papers by staff members of the Bureau of Commercial Fisheries Biological Laboratory in Ann Arbor, Mich., and 35 by associated scientists with whom the Laboratory had contractual or other cooperative arrangements; included also are patents issued to Laboratory personnel. A roster of Laboratory scientists as of December 31, 1964, is appended.

Special Scientific Report - Fisheries↗
USGS2012

Monograph for using paleoflood data in Water Resources Applications

The Environmental and Water Resources Institute (EWRI) Technical Committee on Surface Water Hydrology is sponsoring a Task Committee on Paleoflood Hydrology to prepare a monograph entitled, "Use of Paleoflood and Historical Data in Water Resources Applications." This paper introduces the subject of paleoflood hydrology and discusses the topics, which are expected to be included in the monograph. The procedure for preparing and reviewing the monograph will also be discussed. The paleoflood hydrology monograph will include a discussion of types of hydrologic and paleoflood data, paleostage indicators, flood chronology, modeling methods, interpretation issues, water resources applications and case studies, and research needs. Paleoflood data collection and analysis techniques will be presented, and various applications in water-resources investigations will be provided. An overview of several flood frequency analysis approaches, which consider historical and paleoflood data along with systematic streamflow records, will be presented. The monograph is scheduled for completion and publication in 2001. Copyright ASCE 2004.

Conference Paper↗
USGS2000

National Geochemical Database, U.S. Geological Survey RASS (Rock Analysis Storage System) geochemical data for Alaska

This dataset contains geochemical data for Alaska produced by the analytical laboratories of the Geologic Division of the U.S. Geological Survey (USGS). These data represent analyses of stream-sediment, heavy-mineral-concentrate (derived from stream sediment), soil, and organic material samples. Most of the data comes from mineral resource investigations conducted in the Alaska Mineral Resource Assessment Program (AMRAP). However, some of the data were produced in support of other USGS programs. The data were originally entered into the in-house Rock Analysis Storage System (RASS) database. The RASS database, which contains over 580,000 data records, was used by the Geologic Division from the early 1970's through the late 1980's to archive geochemical data. Much of the data have been previously published in paper copy USGS Open-File Reports by the submitter or the analyst but some of the data have never been published. Over the years, USGS scientists recognized several problems with the database. The two primary issues were location coordinates (either incorrect or lacking) and sample media (not precisely identified). This dataset represents a re-processing of the original RASS data to make the data accessible in digital format and more user friendly. This re-processing consisted of checking the information on sample media and location against the original sample submittal forms, the original analytical reports, and published reports. As necessary, fields were added to the original data to more fully describe the sample preparation methods used and sample medium analyzed. The actual analytical data were not checked in great detail, but obvious errors were corrected.

Alaska↗
USGS2002

38 - Electromagnetic fields generated by earthquakes

Independent knowledge of the physical processes that occur with seismic events can be obtained from observations of electric and magnetic fields generated by these complex processes. During the past few decades, we have seen a remarkable increase in the quality and quantity of electromagnetic (EM) data recorded before and during earthquakes and volcanic eruptions. This paper describes the most significant recent data and the implications these data have for different generating mechanisms. We note that, despite several decades of relatively high quality monitoring, clear demonstration of the existence of precursory EM signals has not been achieved, although causal relations between coseismic magnetic field changes and earthquake stress drops are no longer in question. This paper extends discussions of tectonomagnetism and tectonoelectricity, over the various parts of the electromagnetic spectrum from radio frequencies (RF) to submicrohertz frequencies, that are covered in Johnston (1989, 1997), Park et al. (1993), Park (1996) special journal issues ( Johnston and Parrot, 1989 , 1998; Parrot and Johnston, 1993 ), and books ( Hayakawa and Fujinawa, 1994 ).

International Geophysics↗
USGS1999

Estimating effects of limiting factors with regression quantiles

In a recent Concepts paper in Ecology, Thomson et al. emphasized that assumptions of conventional correlation and regression analyses fundamentally conflict with the ecological concept of limiting factors, and they called for new statistical procedures to address this problem. The analytical issue is that unmeasured factors may be the active limiting constraint and may induce a pattern of unequal variation in the biological response variable through an interaction with the measured factors. Consequently, changes near the maxima, rather than at the center of response distributions, are better estimates of the effects expected when the observed factor is the active limiting constraint. Regression quantiles provide estimates for linear models fit to any part of a response distribution, including near the upper bounds, and require minimal assumptions about the form of the error distribution. Regression quantiles extend the concept of one-sample quantiles to the linear model by solving an optimization problem of minimizing an asymmetric function of absolute errors. Rank-score tests for regression quantiles provide tests of hypotheses and confidence intervals for parameters in linear models with heteroscedastic errors, conditions likely to occur in models of limiting ecological relations. We used selected regression quantiles (e.g., 5th, 10th, ..., 95th) and confidence intervals to test hypotheses that parameters equal zero for estimated changes in average annual acorn biomass due to forest canopy cover of oak (Quercus spp.) and oak species diversity. Regression quantiles also were used to estimate changes in glacier lily (Erythronium grandiflorum) seedling numbers as a function of lily flower numbers, rockiness, and pocket gopher (Thomomys talpoides fossor) activity, data that motivated the query by Thomson et al. for new statistical procedures. Both example applications showed that effects of limiting factors estimated by changes in some upper regression quantile (e.g., 90-95th) were greater than if effects were estimated by changes in the means from standard linear model procedures. Estimating a range of regression quantiles (e.g., 5-95th) provides a comprehensive description of biological response patterns for exploratory and inferential analyses in observational studies of limiting factors, especially when sampling large spatial and temporal scales.

Ecology↗
USGS2005

Field occurrences of liquefaction-induced features: A primer for engineering geologic analysis of paleoseismic shaking

Discussed in this paper are the factors that control the typical manifestations of liquefaction that are found in continental field settings. The factors are given mainly in terms of the local geologic field situation and the geotechnical properties there. A meaningful interpretation of liquefaction-based data for quantitative analysis of paleoseismic shaking requires understanding of both geologic and geotechnical roles in the mode of ground failure at a specific site. Recommendations are made for the size of the field area that must be searched for liquefaction effects, in order to develop adequate data for engineering geologic/geotechnical analyses of paleoseismicity. The areal extent must be based on an appreciation that the tectonic situation can cause seismically induced liquefaction effects to form in some locales, but not in others nearby, even for a strong earthquake in the region. Our guidelines for the conduct of the field search and preliminary analysis of the data relate to three issues for which liquefaction features are especially useful in answering: Has there been strong Holocene/latest Pleistocene shaking in the region? Where was the tectonic source? And what was the strength of shaking? Understanding of the various factors that control the manifestations of liquefaction effects, which we present in this paper, is essential for developing credible answers to these questions. ?? 2004 Elsvier B.V. All rights reserved.

Engineering Geology↗
USGS2011

The North American iron ore industry: A decade into the 21st century

During the 20th century, the iron ore mining industries of Canada and the United States passed through periods of transformation. The beginning of the 21st century has seen another period of transformation, with the failure of a number of steel companies and with consolidation of control within the North American iron ore industry. Canadian and United States iron ore production and the market control structure involved are changing rapidly. Consolidation of ownership, formation of foreign joint ventures, divestitures of upstream activities by steelmakers, and industry changes to ensure availability of feedstocks all played a role in recent developments in the North American iron ore industry. Canadian and U.S. iron ore operations and their strong linkage to downstream production, although isolated, must also be considered within the context of the changing global economy. Projects using new technology to produce direct reduced iron nuggets of 96-98% iron content and other projects designed to produce steel at minesites may once again change the face of the iron ore industry. Social and environmental issues related to sustainable development have had a significant effect on the North American iron ore industry.

Conference Paper↗
USGS2009

Quantifying the undiscovered geothermal resources of the United States

In 2008, the U.S. Geological Survey (USGS) released summary results of an assessment of the electric power production potential from the moderate- and high-temperature geothermal resources of the United States (Williams et al., 2008a; USGS Fact Sheet 2008-3082; http://pubs.usgs.gov/fs/2008/3082). In the assessment, the estimated mean power production potential from undiscovered geothermal resources is 30,033 Megawatts-electric (MWe), more than three times the estimated mean potential from identified geothermal systems: 9057 MWe. The presence of significant undiscovered geothermal resources has major implications for future exploration and development activities by both the government and private industry. Previous reports summarize the results of techniques applied by the USGS and others to map the spatial distribution of undiscovered resources. This paper describes the approach applied in developing estimates of the magnitude of the undiscovered geothermal resource, as well as the manner in which that resource is likely to be distributed among geothermal systems of varying volume and temperature. A number of key issues constrain the overall estimate. One is the degree to which characteristics of the undiscovered resources correspond to those observed among identified geothermal systems. Another is the evaluation of exploration history, including both the spatial distribution of geothermal exploration activities relative to the postulated spatial distribution of undiscovered resources and the probability of successful discoveries from the application of standard geothermal exploration techniques. Also significant are the physical, chemical, and geological constraints on the formation and longevity of geothermal systems. Important observations from this study include the following. (1) Some of the largest identified geothermal systems, such as The Geysers vapor-dominated system in northern California and the diverse geothermal manifestations found in Yellowstone National Park, are unique in North America and highly unlikely to have counterparts with equivalent characteristics among the systems comprising the undiscovered resources. (2) Historical geothermal exploration has been limited in both the effectiveness of techniques employed and spatial coverage, since most exploration has targeted areas associated with surface thermal manifestations in the most easily accessible lands. (3) As noted by other investigators, in general, the hottest and largest geothermal systems are those with heat sources arising from recent magmatic activity. Consequently, a larger fraction of the undiscovered resource is associated with those areas favorable to the formation of this type of geothermal system, including some relatively remote areas, such as the Aleutian volcanic arc in Alaska.

Conference Paper↗