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USGS2002

Black ducks and their Chesapeake Bay habitats: Proceedings of a symposium

The symposium 'Black Ducks and Their Chesapeake Bay Habitats,' held October 4, 2000, provided a forum for scientists to share research about the American black duck (Anas rubripes), an important breeding and wintering waterfowl species dependent upon the Chesapeake Bay habitats. American black ducks have declined significantly in the last 50 years and continue to be a species of management concern. The symposium, sponsored by the Wildfowl Trust of North America and the U.S. Geological Survey, highlighted papers and posters on a range of topics, from the traditional concerns of hunting, habitat, and hybridization to the more recent concerns of human disturbance and neophobia. Other presentations provided a historical perspective of black duck management. The direction that black duck conservation initiatives could and/or should take in the future was also discussed. As populations of humans in the Chesapeake Bay region continue to increase, we can expect that these subjects will receive increased discussion in the future.

Chesapeake Bay↗
USGS2002

Beowulf Distributed Processing and the United States Geological Survey

Introduction In recent years, the United States Geological Survey's (USGS) National Mapping Discipline (NMD) has expanded its scientific and research activities. Work is being conducted in areas such as emergency response research, scientific visualization, urban prediction, and other simulation activities. Custom-produced digital data have become essential for these types of activities. High-resolution, remotely sensed datasets are also seeing increased use. Unfortunately, the NMD is also finding that it lacks the resources required to perform some of these activities. Many of these projects require large amounts of computer processing resources. Complex urban-prediction simulations, for example, involve large amounts of processor-intensive calculations on large amounts of input data. This project was undertaken to learn and understand the concepts of distributed processing. Experience was needed in developing these types of applications. The idea was that this type of technology could significantly aid the needs of the NMD scientific and research programs. Porting a numerically intensive application currently being used by an NMD science program to run in a distributed fashion would demonstrate the usefulness of this technology. There are several benefits that this type of technology can bring to the USGS's research programs. Projects can be performed that were previously impossible due to a lack of computing resources. Other projects can be performed on a larger scale than previously possible. For example, distributed processing can enable urban dynamics research to perform simulations on larger areas without making huge sacrifices in resolution. The processing can also be done in a more reasonable amount of time than with traditional single-threaded methods (a scaled version of Chester County, Pennsylvania, took about fifty days to finish its first calibration phase with a single-threaded program). This paper has several goals regarding distributed processing technology. It will describe the benefits of the technology. Real data about a distributed application will be presented as an example of the benefits that this technology can bring to USGS scientific programs. Finally, some of the issues with distributed processing that relate to USGS work will be discussed.

Open-File Report↗
USGS2000

Assessment of regional earthquake hazards and risk along the Wasatch Front, Utah

This report--the second of two volumes--represents an ongoing effort by the U.S. Geological Survey to transfer accurate Earth science information about earthquake hazards along Utah's Wasatch Front to researchers, public officials, design professionals, land-use planners, and emergency managers in an effort to mitigate the effects of these hazards. This volume contains eight chapters on ground-shaking hazards and aspects of loss estimation.

Utah↗
USGS1976

Hydrologic evaluation of salinity control and reclamation projects in the Indus Plain, Pakistan--A summary

This report summarizes the observations and findings of a team of four specialists from the U.S. Geological Survey assigned to Pakistan under the auspices of the U.S. Agency for International Development during May to August 1972 for a hydrologic evaluation of Salinity Control and Reclamation Projects in the Indus Plain Individual members of the team undertook comprehensive studies related to climatology, surface-water hydrology, and the canal system; streamflow and sediment yields of the rivers; computer applications to hydrologic data; aquifer characteristics; hydrologic evaluation of Salinity Control and Reclamation Projects (SCARPs); tubewell performance; hydrology of shallow versus deep tubewells; well and well-screen design in the Indus Plain; evaluation of observed and anticipated trends in both private and public tubewell development; evaluation of water-quality programs, data analysis, and records, and computer coding of special water-quality data; and evaluation of water-level data, well discharge and specific-capacity tests and aquifer tests. The reclamation program, by pumping from tubewells, has been notably successful in lowering the water table, in providing supplemental water for irrigation and for leaching of salinized soils, and in improving crop production. Some changes in water quality have been observed in SCARP-I and the Mona Scheme of SCARP-II, but these have not as yet (1972) significantly affected the utility of the water for irrigation. Problems associated with reclamation include control of deterioration in performance of tubewells and their rehabilitation, local brackish or saline-water encroachment, and maintenance of a favorable salt balance in the ground-water system. Rapid and as yet (1972) unregulated growth of shallow private tubewell development in the past decade has introduced complicating factors to the reclamation planning of the early 1960's which had emphasized public tubewell development through the SCARP program. In comparing shallow (0-200 feet) with deep (200-400 feet} tubewell development, it is concluded that long-term response of the water table is the same, whether many shallow wells of small capacity or fewer deeper wells of large capacity pump the same total volume of water in the same area. Moreover, it is concluded that there is no definite advantage for either type of pumping regime with respect to water quality. Utilization of the Punjab aquifer could be greatly enhanced by recharge of high-quality water diverted from the Chenab and Jhelum Rivers to the Ravi and Sutlej Rivers by way of the link and irrigation canals during periods of surplus flow. Recharge to the aquifer could also be improved by diversion of high-quality water from the Chenab and the Jhelum to natural nalas and other surface drainageways during periods of surplus flow. Such recharge would be of much better quality than water leaching downward from irrigated fields. Continued monitoring of the hydrologic system and research on problems engendered by reclamation are essential to the viability of the SCARP program and related water-resources development in the Indus River Basin.

Water Supply Paper↗
USGS2005

Variation in fire regimes of the rocky mountains: Implications for avian communities and fire management

Information about avian responses to fire in the U.S. Rocky Mountains is based solely on studies of crown fires. However, fire management in this region is based primarily on studies of low-elevation ponderosa pine (Pinus ponderosa) forests maintained largely by frequent understory fires. In contrast to both of these trends, most Rocky Mountain forests are subject to mixed severity fire regimes. As a result, our knowledge of bird responses to fire in the region is incomplete and skewed toward ponderosa pine forests. Research in recent large wildfires across the Rocky Mountains indicates that large burns support diverse avifauna. In the absence of controlled studies of bird responses to fire, we compared reproductive success for six cavity-nesting species using results from studies in burned and unburned habitats. Birds in ponderosa pine forests burned by stand-replacement fire tended to have higher nest success than individuals of the same species in unburned habitats, but unburned areas are needed to serve species dependent upon live woody vegetation, especially foliage gleaners. Over the last century, fire suppression, livestock grazing, and logging altered the structure and composition of many low-elevation forests, leading to larger and more severe burns. In higher elevation forests, changes have been less marked. Traditional low-severity prescribed fire is not likely to replicate historical conditions in these mixed or high-severity fire regimes, which include many mixed coniferous forests and all lodgepole pine (Pinus contorta) and spruce-fir (Picea-Abies) forests. We suggest four research priorities: (1) the effects of fire severity and patch size on species' responses to fire, (2) the possibility that postfire forests are ephemeral sources for some bird species, (3) the effect of salvage logging prescriptions on bird communities, and (4) experiments that illustrate bird responses to prescribed fire and other forest restoration methods. This research is urgent if we are to develop fire management strategies that reduce fire risk and maintain habitat for avifauna and other wildlife of the Rocky Mountains.

Conference Paper↗
USGS2012

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 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. These models are scheduled to be updated to operate using the most current Environmental Systems Research Institute ArcGIS Geographic Information System platform, and have several improvements implemented to wave calculations, data processing, and functions of the toolbox.

Conference Paper↗
USGS1995

Pinyon-juniper woodlands

Pinyon-juniper woodlands are one of the largest ecosystems in the Southwest and in the Middle Rio Grande Basin (Fig. 1). The woodlands have been important to the region's inhabitants since prehistoric times for a variety of natural resources and amenities. The ecosystems have not been static; their distributions, stand characteristics, and site conditions have been altered by changes in climatic patterns and human use and, often, abuse. Management of these lands since European settlement has varied from light exploitation and benign neglect, to attempts to remove the trees in favor of forage for livestock, and then to a realization that these lands contain useful resources and should be managed accordingly. Land management agencies are committed to ecosystem management. While there are several definitions of ecosystem management, the goal is to use ecological approaches to create and maintain diverse, productive, and healthy ecosystems (Kaufmann et al. 1994). Ecosystem management recognizes that people are an integral part of the system and that their needs must be considered. Ecological approaches are central to the concept, but our understanding of basic woodland ecology is incomplete, and there are different opinions and interpretations of existing information (Gottfried and Severson 1993). There are many questions concerning proper ecosystem management of the pinyon-juniper woodlands and how managers can achieve these goals (Gottfried and Severson 1993). While the broad concept of ecosystem management generally is accepted, the USDA Forest Service, other public land management agencies, American Indian tribes, and private landowners may have differing definitions of what constitutes desired conditions. Key questions about the pinyon-juniper ecosystems remain unanswered. Some concern the basic dynamics of biological and physical components of the pinyon-juniper ecosystems. Others concern the distribution of woodlands prior to European settlement and changes since the introduction of livestock and fire control. This relates to whether tree densities have been increasing or whether trees are invading grasslands and, to a lesser extent, drier ponderosa pine (Pinus ponderosa) forests. In areas where woodlands were heavily used by American Indians for fuelwood prior to European contact, the advance of pinyon and juniper could represent the slow recovery from intensive use (Samuels and Betancourt 1982). There are numerous questions regarding declines in watershed condition related to changes in pinyon-juniper tree stand densities and to the density and composition of understory vegetation. There are different opinions about proper management of woodland ecosystems. Should these lands be managed for a single resource, such as forage for livestock production, or managed for sustained production of multiple resource products and amenities? Depending on site and stand conditions, the woodlands can produce variable quantities of fuelwood, pinyon nuts, wildlife habitat, forage for livestock, and cover for watershed protection. Management must also consider increasing recreational demands, threatened and endangered species, and protection of archeological sites. Many pinyon-juniper woodland watersheds in New Mexico have unsatisfactory soil and watershed conditions (USDA Forest Service 1993); managers must develop restoration procedures that recognize the value of woodland ecosystems. The concerns, questions, and conflicts surrounding management of pinyon-juniper lands, as well as the ecological foundations of ecosystem management, require that all interested parties reevaluate attitudes toward the woodlands. Ecosystem management goals and concepts recognize diversity. Pinyonjuniper woodlands are diverse, and stand characteristics and site productivities vary. Management objectives and prescriptions must evaluate the potential of each site, and decisions must be based on sound scientific information. This information is often unavailable. Therefore, this paper describes what we do know about the characteristics, distribution, and ecology of pinyon-juniper woodlands, including the effects of natural and human factors, within the southwestern United States and particularly the Middle Rio Grande Basin. It also reviews some past and present management options in this widespread and important vegetation type. The review draws on research and management information from the Rio Grande Basin and from similar areas in the Southwest and adjacent regions. It does not attempt to review all of the relevant literature; additional sources can be found within the articles cited in the References.

General Technical Report↗
USGS2012

Guidelines for a graph-theoretic implementation of structural equation modeling

Structural equation modeling (SEM) is increasingly being chosen by researchers as a framework for gaining scientific insights from the quantitative analyses of data. New ideas and methods emerging from the study of causality, influences from the field of graphical modeling, and advances in statistics are expanding the rigor, capability, and even purpose of SEM. Guidelines for implementing the expanded capabilities of SEM are currently lacking. In this paper we describe new developments in SEM that we believe constitute a third-generation of the methodology. Most characteristic of this new approach is the generalization of the structural equation model as a causal graph. In this generalization, analyses are based on graph theoretic principles rather than analyses of matrices. Also, new devices such as metamodels and causal diagrams, as well as an increased emphasis on queries and probabilistic reasoning, are now included. Estimation under a graph theory framework permits the use of Bayesian or likelihood methods. The guidelines presented start from a declaration of the goals of the analysis. We then discuss how theory frames the modeling process, requirements for causal interpretation, model specification choices, selection of estimation method, model evaluation options, and use of queries, both to summarize retrospective results and for prospective analyses. The illustrative example presented involves monitoring data from wetlands on Mount Desert Island, home of Acadia National Park. Our presentation walks through the decision process involved in developing and evaluating models, as well as drawing inferences from the resulting prediction equations. In addition to evaluating hypotheses about the connections between human activities and biotic responses, we illustrate how the structural equation (SE) model can be queried to understand how interventions might take advantage of an environmental threshold to limit Typha invasions. The guidelines presented provide for an updated definition of the SEM process that subsumes the historical matrix approach under a graph-theory implementation. The implementation is also designed to permit complex specifications and to be compatible with various estimation methods. Finally, they are meant to foster the use of probabilistic reasoning in both retrospective and prospective considerations of the quantitative implications of the results.

Ecosphere↗
USGS2024

Preface to focus section on new frontiers and advances in global seismology

Over the last century, many of the fundamental advances in our understanding of the solid Earth have been underpinned by seismic observations recorded on long‐running networks of globally distributed seismic instruments (e.g., Agnew et al. , 1976; Romanowicz et al. , 1984; Hanka and Kind, 1994; Peterson and Hutt, 2014; Ringler et al. , 2022a). During this time, seismic data quality and the speed of dissemination have improved substantially from early analog paper records to digital, very broadband data transmitted in near‐real time (Steim, 2015) and rapidly archived in online data repositories with...

Seismological Research Letters↗
USGS2003

Effects of ammonium perchlorate on the reproductive performance and thyroid follicle histology of zebrafish

Adult zebrafish were reared up to eight weeks in control water or in water containing ammonium perchlorate (AP) at measured perchlorate concentrations of 18 (environmentally relevant, high) and 677 ppm. Groups of eight females were paired with four males on a weekly basis to assess AP effects on spawned egg volume, an index of reproductive performance. All treatments were applied to four to five spawning replicates. At 677 ppm, spawn volume was reduced within one week and became negligible after four weeks. At 18 ppm, spawn volume was unaffected even after eight weeks. Also, perchlorate at 18 ppm did not affect percentage egg fertilization. Fish were collected at the end of the exposures (677 ppm, four weeks; control and 18 ppm, eight weeks) for whole-body perchlorate content and thyroid histopathological analysis. Fish perchlorate levels were about one-hundredth of those of treatment water levels, indicating that waterborne perchlorate does not accumulate in whole fish. At 677 ppm for four weeks, perchlorate caused thyroid follicle cell (nuclear) hypertrophy and angiogenesis, whereas at 18 ppm for eight weeks, its effects were more pronounced and included hypertrophy, angiogenesis, hyperplasia, and colloid depletion. In conclusion, an eight-week exposure of adult zebrafish to 18 ppm perchlorate (high environmentally relevant concentrations) affected the histological condition of their thyroid follicles but not their reproductive performance. The effect of 677 ppm perchlorate on reproduction may be due to extrathyroidal toxicity. Further research is needed to determine if AP at lower environmentally relevant concentrations also affects the thyroid follicles of zebrafish.

Conference Paper↗
USGS2012

Development and application of downscaled hydroclimatic predictor variables for use in climate vulnerability and assessment studies

This paper outlines the production of 270-meter grid-scale maps for 14 climate and derivative hydrologic variables for a region that encompasses the State of California and all the streams that flow into it. The paper describes the Basin Characterization Model (BCM), a map-based, mechanistic model used to process the hydrological variables. Three historic and three future time periods of 30 years (1911–1940, 1941–1970, 1971–2000, 2010–2039, 2040–2069, and 2070–2099) were developed that summarize 180 years of monthly historic and future climate values. These comprise a standardized set of fine-scale climate data that were shared with 14 research groups, including the U.S. National Park Service and several University of California groups as part of this project. We present three analyses done with the outputs from the Basin Characterization Model: trends in hydrologic variables over baseline, the most recent 30-year period; a calibration and validation effort that uses measured discharge values from 139 streamgages and compares those to Basin Characterization Model-derived projections of discharge for the same basins; and an assessment of the trends of specific hydrological variables that links historical trend to projected future change under four future climate projections. Overall, increases in potential evapotranspiration dominate other influences in future hydrologic cycles. Increased potential evapotranspiration drives decreasing runoff even under forecasts with increased precipitation, and drives increased climatic water deficit, which may lead to conversion of dominant vegetation types across large parts of the study region as well as have implications for rain-fed agriculture. The potential evapotranspiration is driven by air temperatures, and the Basin Characterization Model permits it to be integrated with a water balance model that can be derived for landscapes and summarized by watershed. These results show the utility of using a process-based model with modules representing different hydrological pathways that can be inter-linked.

California↗
USGS2015

Predicting ecological responses of the Florida Everglades to possible future climate scenarios: Introduction

Florida’s Everglades stretch from the headwaters of the Kissimmee River near Orlando to Florida Bay. Under natural conditions in this flat landscape, water flowed slowly downstream as broad, shallow sheet flow. The ecosystem is markedly different now, altered by nutrient pollution and construction of canals, levees, and water control structures designed for flood control and water supply. These alterations have resulted in a 50 % reduction of the ecosystem’s spatial extent and significant changes in ecological function in the remaining portion. One of the world’s largest restoration programs is underway to restore some of the historic hydrologic and ecological functions of the Everglades, via a multi-billion dollar Comprehensive Everglades Restoration Plan. This plan, finalized in 2000, did not explicitly consider climate change effects, yet today we realize that sea level rise and future changes in rainfall (RF), temperature, and evapotranspiration (ET) may have system-wide impacts. This series of papers describes results of a workshop where a regional hydrologic model was used to simulate the hydrology expected in 2060 with climate changes including increased temperature, ET, and sea level, and either an increase or decrease in RF. Ecologists with expertise in various areas of the ecosystem evaluated the hydrologic outputs, drew conclusions about potential ecosystem responses, and identified research needs where projections of response had high uncertainty. Resource managers participated in the workshop, and they present lessons learned regarding how the new information might be used to guide Everglades restoration in the context of climate change.

Florida↗
USGS2011

Earthquake mechanism and displacement fields close to fault zones: Report on the Sixth GEOP Research Conference

The Sixth Geodesy/Solid Earth and Ocean Physics (GEOP) Research Conwas held on February 4–5, 1974, at the Institute of Geophysics and Planetary Physics, University of California, San Diego, in La Jolla, California. It was attended by about 100 persons. James N. Brune, program chairman, opened the conference and delivered the introductory address, a somewhat extended version of which is printed elsewhere in this issue. Brune's paper and the following summaries of the sessions constitute a report of the conference.

Eos, Transactions, American Geophysical Union↗
USGS2015

An evaluation of unsupervised and supervised learning algorithms for clustering landscape types in the United States

Knowledge of landscape type can inform cartographic generalization of hydrographic features, because landscape characteristics provide an important geographic context that affects variation in channel geometry, flow pattern, and network configuration. Landscape types are characterized by expansive spatial gradients, lacking abrupt changes between adjacent classes; and as having a limited number of outliers that might confound classification. The US Geological Survey (USGS) is exploring methods to automate generalization of features in the National Hydrography Data set (NHD), to associate specific sequences of processing operations and parameters with specific landscape characteristics, thus obviating manual selection of a unique processing strategy for every NHD watershed unit. A chronology of methods to delineate physiographic regions for the United States is described, including a recent maximum likelihood classification based on seven input variables. This research compares unsupervised and supervised algorithms applied to these seven input variables, to evaluate and possibly refine the recent classification. Evaluation metrics for unsupervised methods include the Davies–Bouldin index, the Silhouette index, and the Dunn index as well as quantization and topographic error metrics. Cross validation and misclassification rate analysis are used to evaluate supervised classification methods. The paper reports the comparative analysis and its impact on the selection of landscape regions. The compared solutions show problems in areas of high landscape diversity. There is some indication that additional input variables, additional classes, or more sophisticated methods can refine the existing classification.

Cartography and Geographic Information Science↗
USGS2007

Environmental effects of off-highway vehicles on Bureau of Land Management lands: A literature synthesis, annotated bibliographies, extensive bibliographies, and internet resources

This report and its associated appendixes compile and synthesize the results of a comprehensive literature and Internet search conducted in May 2006. The literature search was undertaken to uncover information regarding the effects of off-highway vehicle (OHV) use on land health, or “natural resource attributes,” and included databases archiving information from before OHVs came into existence to May 2006. Information pertaining to socioeconomic implications of OHV activities is included as well. The literature and Internet searches yielded approximately 700 peer-reviewed papers, magazine articles, agency and non-governmental reports, and internet websites regarding effects of OHV use as they relate to the Bureau of Land Management’s (BLM) standards of land health. Discussions regarding OHV effects are followed by brief syntheses of potential indicators of OHV effects, as well as OHV-effects mitigation, site-restoration techniques, and research needs.

Open-File Report↗
USGS2006

The Model Parameter Estimation Experiment (MOPEX): Its structure, connection to other international initiatives and future directions

The Model Parameter Estimation Experiment (MOPEX) is an international project aimed at developing enhanced techniques for the a priori estimation of parameters in hydrological models and in land surface parameterization schemes connected to atmospheric models. The MOPEX science strategy involves: database creation, a priori parameter estimation methodology development, parameter refinement or calibration, and the demonstration of parameter transferability. A comprehensive MOPEX database has been developed that contains historical hydrometeorological data and land surface characteristics data for many hydrological basins in the United States (US) and in other countries. This database is being continuously expanded to include basins from various hydroclimatic regimes throughout the world. MOPEX research has largely been driven by a series of international workshops that have brought interested hydrologists and land surface modellers together to exchange knowledge and experience in developing and applying parameter estimation techniques. With its focus on parameter estimation, MOPEX plays an important role in the international context of other initiatives such as GEWEX, HEPEX, PUB and PILPS. This paper outlines the MOPEX initiative, discusses its role in the scientific community, and briefly states future directions.

IAHS-AISH Publication↗
USGS2001

Recommended features of protocols for long-term ecological monitoring

In 1991, the National Park Service (NPS) selected seven parks to serve as prototypes for development of a long-term ecological monitoring program. Denali National Park and Preserve was one of the prototype parks selected. The principal focus of this national program was to detect and document resource changes and to understand the forces driving those changes. One of the major tasks of each prototype park was to develop monitoring protocols. In this paper, we discuss some lessons learned and what we believe to be the most important features of protocols. One of the many lessons we have learned is that monitoring protocols vary greatly in content and format. This variation leads to confusion about what information protocols should contain and how they should be formatted. Problems we have observed in existing protocols include (1) not providing enough detail, (2) omitting critical topics (such as data management), and (3) mixing explanation with instructions. Once written, protocols often sit on the shelf to collect dust, allowing methods changes to occur without being adequately considered, tested, or documented. Because a lengthy and costly research effort is often needed to develop protocols, a vision of what the final product should look like is helpful. Based on our involvement with the prototype monitoring program for Denali (Oakley and Boudreau 2000), we recommend key features of protocols, including a scheme for linking protocols to data in the data management system and for tracking protocol revisions. A protocol system is crucial for producing long-term data sets of known quality that meet program objectives.

Conference Paper↗