USGS Science⌕ Search

SEARCH · USGS Science

Results for “Special Paper”

Search indexed USGS publications on groundwater, aquifers, geologic maps, mineral resources and earthquakes. Explore source records by subject and place.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 523 records · Page 29Linked to original sources
USGS2018

UZIG research: Measurement and characterization of unsaturated zone processes under wide-ranging climates and changing conditions

Unsaturated zone properties and processes are central to understanding the interacting effects of land-use change, contamination, and hydroclimate on our ability to grow food, sustain clean water supplies, and minimize loss of life and property. Advances in unsaturated zone science are being achieved through collaborations across traditional boundaries where information from biological, physical, and chemical disciplines is combined for new insights. The Unsaturated Zone Interest Group (UZIG) is an organization that exists principally to promote multidisciplinary collaborations and the sharing of ideas, expertise, and technical assets. Here we summarize key findings from 14 papers, several of which originated from a meeting convened by UZIG in 2017 at the University of Florida in Gainesville titled “Land-Use Change, Climate Change, and Hydrologic Extremes: Unsaturated Zone Responses and Feedbacks.” This special section of Vadose Zone Journal contains multidisciplinary research in three general categories relevant to measuring and understanding unsaturated zone responses to changing land uses and climate: (i) unsaturated zone properties and processes; (ii) soil–plant–atmosphere interactions; and (iii) novel field sampling devices. A strong cross-cutting theme in these papers is the value of continuous monitoring data and ways of utilizing them to discover novel hydrologic, biologic, and pedologic information. As climatic and land-use conditions change and demands for resources and stresses on ecosystems continue to intensify, it is vital to improve our fundamental understanding of the processes at work in the unsaturated zone. Toward that goal, we discuss the need for improved ground-based unsaturated zone monitoring networks.

Vadose Zone Journal↗
USGS1990

Stability analysis of Eulerian-Lagrangian methods for the one-dimensional shallow-water equations

In this paper stability and error analyses are discussed for some finite difference methods when applied to the one-dimensional shallow-water equations. Two finite difference formulations, which are based on a combined Eulerian-Lagrangian approach, are discussed. In the first part of this paper the results of numerical analyses for an explicit Eulerian-Lagrangian method (ELM) have shown that the method is unconditionally stable. This method, which is a generalized fixed grid method of characteristics, covers the Courant-Isaacson-Rees method as a special case. Some artificial viscosity is introduced by this scheme. However, because the method is unconditionally stable, the artificial viscosity can be brought under control either by reducing the spatial increment or by increasing the size of time step. The second part of the paper discusses a class of semi-implicit finite difference methods for the one-dimensional shallow-water equations. This method, when the Eulerian-Lagrangian approach is used for the convective terms, is also unconditionally stable and highly accurate for small space increments or large time steps. The semi-implicit methods seem to be more computationally efficient than the explicit ELM; at each time step a single tridiagonal system of linear equations is solved. The combined explicit and implicit ELM is best used in formulating a solution strategy for solving a network of interconnected channels. The explicit ELM is used at channel junctions for each time step. The semi-implicit method is then applied to the interior points in each channel segment. Following this solution strategy, the channel network problem can be reduced to a set of independent one-dimensional open-channel flow problems. Numerical results support properties given by the stability and error analyses.

Applied Mathematical Modelling↗
USGS2004

Development of an AMS method to study oceanic circulation characteristics using cosmogenic 39Ar

Initial experiments at the ATLAS facility [Nucl. Instr. and Meth. B 92 (1994) 241] resulted in a clear detection of cosmogenic 39Ar signal at the natural level. The present paper summarizes the recent developments of 39Ar AMS measurements at ATLAS: the use of an electron cyclotron resonance (ECR) positive ion source equipped with a special quartz liner to reduce 39K background, the development of a gas handling system for small volume argon samples, the acceleration of 39Ar8+ ions to 232 MeV, and the final separation of 39Ar from 39K in a gas-filled spectrograph. The first successful AMS measurements of 39Ar in ocean water samples from the Southern Atlantic ventilation experiment (SAVE) are reported. Published by Elsevier B.V.

Conference Paper↗
USGS1969

Hydrology of carbonate rock terranes — A review: With special reference to the United States

Limestone and other carbonate rocks are characterized by many unusual features and extreme conditions, either involving the hydrologic system within them or wrought by hydrologic conditions on them or through them. Perhaps there could be little agreement as to what is typical or average for the many features of carbonate rocks, as indicated by the following conditions: bare rock and thin soils are common, but so are thick soils; very highly permeable limestones are common, but so are poorly permeable ones; and rugged karst topographic features with underlying solution caverns are common, but so are flat, nearly featureless topographic conditions. Some conditions of carbonate terranes are suitable to man's needs and interests, such as the use of some permeable aquifers for water supply and the exploitation of caves for tourist attractions. On the other hand, many problems may exist, including: permeability too low for adequate water supply or so high that the aquifer retains too little water for use during periods of fair weather, soils too thin for growing of crops and for adequate filtration of wastes near the ground surface, instability of the ground for buildings and foundations in sinkhole areas, and unusually rugged topography. Some of the many variable conditions are readily observable, but others can be determined only by careful geologic and hydrologic studies. The need for knowing the specific geologic and hydrologic conditions at various places in limestone terranes, as well as the variations in hydrologic conditions with changing conditions and time, has resulted in many published reports on local areas and on special topical problems of limestone hydrology. Many of these reports have been used to advantage by the present writers in preparing this paper. The concept that secondary permeability is developed by circulation of water through openings with the accompanying enlargement of these openings by solution is now universally accepted in limestone terranes. Emphasis is placed on the hydrogeologic framework, or structural setting, in relation to the ease or difficulty of water to move from a source of recharge, through a part of the limestone, to a discharge area. Parts of the limestone favored by circulating ground water tend to develop solution openings, commonly in the upper part of the zone of saturation; as base level is lowered (sea level or perennial stream level), the related water table lowers in the limestone leaving air-filled caverns above the present zone of saturation in sinkhole areas. Reconstruction of the geologic and hydrologic history of a limestone area aids in determining the extent of development and the positions of fossil and present permeability. References are made to the hydrology of many limestone regions, especially those of the United States.

Journal of Hydrology↗
USGS2026

Global change and threats to waterbirds in the Asian flyways

Avian migration represents one of nature’s most spectacular phenomena, providing critical ecological services and acting as an indicator of environmental change. Flyways are geographical ranges through which migrating bird species move, and the flyway concept has been used to identify countries that share species to highlight their collective responsibility for conservation. Of the nine recognized global waterbird flyways, the Central Asian Flyway (CAF) and the East Asian–Australasian Flyway (EAAF) are among the most important areas in Eurasia, supporting millions of waterbirds across a vast network of habitats. We proposed this special issue in Avian Research entitled “Global Change and Threats to Waterbirds in the Asian Flyways” to synthesize recent findings from 12 papers covering a wide range of topics. The CAF stretches from the Siberian tundra through Central Asia including Mongolia, the Qinghai-Tibet Plateau, the Trans-Caucasus, and the Himalayas, extending south to the Indian subcontinent and parts of the Middle East. The EAAF spans eastern Siberia and Alaska to Southeast Asia, Australia, and New Zealand, including China, Japan, the Korean Peninsula, and the Russian Far East. These two flyways include 47 countries comprising critical wetlands, river basins, and coastal areas, which are vital breeding, stopover, and wintering grounds for waterbirds. Seasonal migration in these flyways is fundamentally influenced by climate and weather conditions, land cover dynamics, and anthropogenic activities, and contributes significantly to ecological processes such as pest control, nutrient cycling, and organism dispersal. However, migratory waterbirds and their habitats are undergoing enormous challenges. Changes in climate, habitat availability and connectivity, and human activities are altering the phenology, distribution, population dynamics, and health of the migratory bird populations. As migratory waterbirds travel across international boundaries, understanding their movements and responses to environmental change requires collaborative, cross-border research efforts that promote knowledge sharing and interdisciplinary approaches.

Avian Research↗
USGS2011

Preface to the Focused Issue on the 22 February 2011 Magnitude 6.2 Christchurch Earthquake

The 22 February 2011 magnitude 6.2 Christchurch earthquake, centered southeast of Christchurch, was part of the aftershock sequence that has been occurring since the September 2010 magnitude 7.1 quake near Darfield, 40 km west of the city. The Christchurch earthquake killed more than 180 people, damaged or destroyed more than 100,000 buildings, and is New Zealand's most deadly disaster since the earthquake that struck the Napier and Hastings area on 3 February 1931. This special focused issue of Seismological Research Letters , which I had the fortune to edit, contains a selected set of 19 original technical papers. These papers cover different aspects of the 2011 Christchurch earthquake from seismological, geodetic, geological, and engineering perspectives.

Christchurch↗
USGS2011

Preface: Multiscale feedbacks in ecogeomorphology

Geomorphic systems are known to exhibit nonlinear responses to physical–biological feedbacks (Thornes, 1985; Baas, 2002; Reinhardt et al., 2010). These responses make understanding and/or predicting system response to change highly challenging. With growing concerns over ecosystem health, a pressing need exists for research that tries to elucidate these feedbacks (Jerolmack, 2008; Darby, 2010; National Research Council, 2010). A session was convened at the Fall 2008 meeting of the American Geophysical Union (AGU) to provide an outlet for some of this truly interdisciplinary and original research, which is central to understanding geomorphic and ecological dynamics. The session attracted over 39 contributions, which were divided into two well-attended oral sessions and a very busy poster session. This special issue presents new research from the AGU session, which highlights clear physical–biological feedbacks. The aim is to bring together contrasting perspectives on biological and geomorphic feedbacks in a diversity of physiographic settings, ranging from wetlands and estuaries, through rivers, to uplands. These papers highlight biological and physical feedbacks which involve the modulation or amplification of geomorphic processes. These papers will be of interest to a core geomorphology audience, and should also draw attention from the fields of ecohydraulics, hydroecology, ecohydrology, ecomorphology, biogeochemistry and biogeography, and biogeomorphology as well as the more traditional fields of hydrology, ecology and biology. In this preface to the special issue, we a) review past contributions to the emerging field of ecogeomorphology and related disciplines, b) provide some context for how this topical special issue came to fruition, and c) summarize the contributions to this special issue.

Geomorphology↗
USGS2017

Acoustic telemetry and fisheries management

This paper reviews the use of acoustic telemetry as a tool for addressing issues in fisheries management, and serves as the lead to the special Feature Issue of Ecological Applications titled “Acoustic Telemetry and Fisheries Management” . Specifically, we provide an overview of the ways in which acoustic telemetry can be used to inform issues central to the ecology, conservation, and management of exploited and/or imperiled fish species. Despite great strides in this area in recent years, there are comparatively few examples where data have been applied directly to influence fisheries management and policy. We review the literature on this issue, identify the strengths and weaknesses of work done to date, and highlight knowledge gaps and difficulties in applying empirical fish telemetry studies to fisheries policy and practice. We then highlight the key areas of management and policy addressed, as well as the challenges that needed to be overcome to do this. We conclude with a set of recommendations about how researchers can, in consultation with stock assessment scientists and managers, formulate testable scientific questions to address and design future studies to generate data that can be used in a meaningful way by fisheries management and conservation practitioners. We also urge the involvement of relevant stakeholders (managers, fishers, conservation societies, etc.) early on in the process (i.e. in the co-creation of research projects), so that all priority questions and issues can be addressed effectively.

Ecological Applications↗
USGS2022

Opportunities for businesses to use and support development of SEEA-aligned natural capital accounts

Global understanding of the interconnections between the environment and economy has increased, driving the development of frameworks and standards that support the measurement and valuation of natural capital and ecosystem services by both governments and businesses. This paper outlines how businesses can use natural capital accounts (NCA) aligned to the System of Environmental Economic Accounting (SEEA) standard described in this special issue to support identification, management, and valuation of natural capital not typically listed on corporate balance sheets. Such accounts have direct applications for business strategic planning, investment decisions, supply chain management , operations management, risk management, and corporate reporting. Businesses also have important roles to play in advancing SEEA-aligned NCA by providing information that would be useful to include in the accounts and by helping to shape accounts to provide decision-relevant information for both the private and the public sectors. Current pilot SEEA-aligned NCA data and analyses developed for the United States can help address some of the common challenges that businesses face in using natural capital data such as accessibility, quality, and credibility, important for business decision making. However, improvements are needed to fill data gaps and produce more frequent and timely estimates aligned to the temporal resolution needed by businesses.

Ecosystem Services↗
USGS1986

Immunoblot assay: a rapid and sensitive method for identification of salmonid fish viruses

An immunoblot assay was used to identify the viruses of infectious pancreatic necrosis, infectious hematopoietic necrosis, and viral hemorrhagic septicemia. Viral antigen in infected cell culture supernatant was adsorbed onto nitrocellulose membrane or Whatman 541 filter paper and detected by enzyme-linked immunosorbent assay techniques. The immunoblot assay took less than 4 hr to perform and required no special instrumentation. Assays using cell culture supernatant fluids showed immunoblot sensitivity was 10 5 –10 6 PFU/ml. Assay sensitivity, determined using purified virus, is 0.85–4.0 ng of viral antigen. The immunoblot assay was used to detect and identify virus in cell culture fluids.

Journal of Wildlife Diseases↗
USGS1974

Feeding ecology of pintail hens during reproduction

Food supply has been acknowledged as one of eight major external factors regulating the sexual cycles of birds (Marshall 1961). Several hypotheses have been advanced to explain the role of food supply as an ultimate factor regulating breeding (Marshall 1951; Lack 1954, 1968; Wynne-Edwards 1962; and others). Another potential influence of food is its being a proximate stimulus to breeding. When certain foods become available they may act as a stimulus as the female requires them to meet her dietary needs during egg formation. Lack (1966a: 24) suggested that the average date of laying by the Great Tit ( Parus major ) probably resulted from a correlation between spring temperatures and the time of appearance of the insect foods the adult females need to form eggs. He also cited other passerines whose breeding was affected by food supply available to the female. In waterfowl it has been suggested that laying females require invertebrate foods (Moyle 1961, Leitch 1964). If true, this implies that the timing of laying is influenced by those environmental changes that affect food supply. The Pintail ( Anas acuta ) lives primarily on plant foods during much of the year (Martin et al. 1951); thus a study of feeding ecology during the nesting season provided an opportunity to evaluate the significance of an invertebrate food source to females during the period of egg formation. Marshall (1951) stated that essentially vegetarian species appear compelled to switch at least partially to a heavier protein diet when feeding their developing young. Production of a clutch of eggs, like tissue growth in the young, requires a special dietary need that presumably should be reflected in the diet of vegetarian species during the period that eggs are being formed. This paper describes the diet of the female Pintail prior to, during, and after laying and discusses the impact of certain environmental and physiological changes on Pintail breeding.

The Auk↗
USGS2000

Landsat 7 processing on the EROS Data Center's National Land Archive Processing System (NLAPS)

Staff at the U.S. Geological Survey (USGS) EROS Data Center (EDC) process Landsat 7 data for customer distribution on two distinct systems. The Distributed Active Archive Center (DAAC) processing is done on the Level -1 Product Generation System (LPGS), and the USGS processing is completed on the National Land Archive Processing System (NLAPS). The NLAPS is capable of processing data from Landsat 1-5 and 7 and SPOT 1-3. The data can be processed with correction levels ranging from Level-0 raw data to terrain-corrected precision products in a variety of output formats. The NLAPS processing system requires that different ordering procedures be used for standard recipe versus special order processing, and it makes available many processing and framing options. The NLAPS draws on a ground control point library whose sources range from paper maps to textual descriptions and registered source imagery, such as digital orthophoto quadrangles. The accuracy of the final products will vary depending on the level of correction applied and the source of the ground control points used for the precision corrections. An accuracy assessment of the LPGS systematic product versus the NLAPS systematic product demonstrates that both systems provide the same geometric and radiometric accuracy in systematically corrected products.

Conference Paper↗
USGS1923

The occurrence of ground water in the United States, with a discussion of principles

The writer has planned and partly prepared a series of six papers on ground water in the United States. These papers are to deal with (1) occurrence, (2) origin, discharge, and quantity, (3) movement and head, (4) quality, (5) recovery and use, and (6) ground-water provinces. The present paper is the first of the series. The writer is indebted to many colaborers for assistance in preparing this paper, especially to the following members of the United States Geological Survey: M. R. Campbell, who read the entire paper; E. W. Shaw, C. E. Van Orstrand, A. F. Melcher, and C. K. Wentworth, who examined Chapter I; W. C. Alden, who examined Chapters II and IV with special reference to their statements regarding glacial geology; E. S. Larsen, who examined a part of Chapter II; G. W. Stosfi, who examined Chapter III; T. W. Stanton, who examined Chapter IV; L. W. Stephenson, who examined the parts of Chapter IV that relate to the Coastal Plain; C. W. Cooke, who furnished many unpublished data on the geology of the Coastal Plain; Miss M. G. Wilmarth, who gave valuable help in compiling the geologic sections; D. G. Thompson and Miss Norah E. Dowell, who furnished original data on the mechanical composition and porosity of various sedimentary materials; B. H. Lane, who made valuable criticisms of the text; and Martin Solem, who had charge of the preparation of the illustrations.

Water Supply Paper↗
USGS1991

New hydrologic instrumentation in the U.S. Geological Survey

New water-level sensing and recording instrumentation is being used by the U.S. Geological Survey for monitoring water levels, stream velocities, and water-quality characteristics. Several of these instruments are briefly described. The Basic Data Recorder (BDR) is an electronic data logger, that interfaces to sensor systems through a serial-digital interface standard (SDI-12), which was proposed by the data-logger industry; the Incremental Shaft Encoder is an intelligent water-level sensor, which interfaces to the BDR through the SDI-12; the Pressure Sensor is an intelligent, nonsubmersible pressure sensor, which interfaces to the BDR through the SDI-12 and monitors water levels from 0 to 50 feet; the Ultrasonic Velocity Meter is an intelligent, water-velocity sensor, which interfaces to the BDR through the SDI-12 and measures the velocity across a stream up to 500 feet in width; the Collapsible Hand Sampler can be collapsed for insertion through holes in the ice and opened under the ice to collect a water sample; the Lighweight Ice Auger, weighing only 32 pounds, can auger 6- and 8-inch holes through approximately 3.5 feet of ice; and the Ice Chisel has a specially hardened steel blade and 6-foot long, hickory D-handle.

Conference Paper↗
USGS2003

Managing a subsidized predator population: Reducing common raven predation on desert tortoises

Human communities often are an inadvertent source of food, water, and other resources to native species of wildlife. Because these resources are more stable and predictable than those in a natural environment, animals that subsist on them are able to increase in numbers and expand their range, much to the detriment of their competitors and species they prey upon. In the Mojave Desert, common ravens (Corvus corax) have benefited from human-provided resources to increase in population size precipitously in recent years. This trend has caused concern because ravens prey on juvenile desert tortoises (Gopherus agassizii), a federally threatened species. In this paper, I discuss management strategies to reduce raven predation on desert tortoises. The recommendations fall into three categories: (1) managing raven populations by reducing access to anthropogenic resources; (2) removing offending ravens or other birds in specially targeted tortoise management zones; and (3) continuing research on raven ecology, raven behavior, and methods of reducing raven predation on tortoises. I also recommend approaching the problem within an adaptive management framework: management efforts should first be employed as scientific experiments - with replicates and controls - to yield an unbiased assessment of their effectiveness. Furthermore, these strategies should be implemented in concert with actions that reduce other causes of desert tortoise mortality to aid the long-term recovery of their populations. Overall, the approaches outlined in this paper are widely applicable to the management of subsidized predators, particularly where they present a threat to a declining species of prey.

Environmental Management↗
USGS2017

Impacts of coastal land use and shoreline armoring on estuarine ecosystems: An introduction to a special issue

The nearshore land-water interface is an important ecological zone that faces anthropogenic pressure from development in coastal regions throughout the world. Coastal waters and estuaries like Chesapeake Bay receive and process land discharges loaded with anthropogenic nutrients and other pollutants that cause eutrophication, hypoxia, and other damage to shallow-water ecosystems. In addition, shorelines are increasingly armored with bulkhead (seawall), riprap, and other structures to protect human infrastructure against the threats of sea-level rise, storm surge, and erosion. Armoring can further influence estuarine and nearshore marine ecosystem functions by degrading water quality, spreading invasive species, and destroying ecologically valuable habitat. These detrimental effects on ecosystem function have ramifications for ecologically and economically important flora and fauna. This special issue of Estuaries and Coasts explores the interacting effects of coastal land use and shoreline armoring on estuarine and coastal marine ecosystems. The majority of papers focus on the Chesapeake Bay region, USA, where 50 major tributaries and an extensive watershed (~ 167,000 km 2 ), provide an ideal model to examine the impacts of human activities at scales ranging from the local shoreline to the entire watershed. The papers consider the influence of watershed land use and natural versus armored shorelines on ecosystem properties and processes as well as on key natural resources.

Estuaries and Coasts↗