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At least 415 records · Page 23Linked to original sources

USGS2014

U.S. Geological Survey's ShakeCast: A cloud-based future

When an earthquake occurs, the U. S. Geological Survey (USGS) ShakeMap portrays the extent of potentially damaging shaking. In turn, the ShakeCast system, a freely-available, post-earthquake situational awareness application, automatically retrieves earthquake shaking data from ShakeMap, compares intensity measures against users’ facilities, sends notifications of potential damage to responsible parties, and generates facility damage assessment maps and other web-based products for emergency managers and responders. ShakeCast is particularly suitable for earthquake planning and response purposes by Departments of Transportation (DOTs), critical facility and lifeline utilities, large businesses, engineering and financial services, and loss and risk modelers. Recent important developments to the ShakeCast system and its user base are described. The newly-released Version 3 of the ShakeCast system encompasses advancements in seismology, earthquake engineering, and information technology applicable to the legacy ShakeCast installation (Version 2). In particular, this upgrade includes a full statistical fragility analysis framework for general assessment of structures as part of the near real-time system, direct access to additional earthquake-specific USGS products besides ShakeMap (PAGER, DYFI?, tectonic summary, etc.), significant improvements in the graphical user interface, including a console view for operations centers, and custom, user-defined hazard and loss modules. The release also introduces a new adaption option to port ShakeCast to the "cloud". Employing Amazon Web Services (AWS), users now have a low-cost alternative to local hosting, by fully offloading hardware, software, and communication obligations to the cloud. Other advantages of the "ShakeCast Cloud" strategy include (1) Reliability and robustness of offsite operations, (2) Scalability naturally accommodated, (3), Serviceability, problems reduced due to software and hardware uniformity, (4) Testability, freely available for new users, (5) Remotely supported, allowing expert-facilitated maintenance, (6) Adoptability, simplified with disk images, and (7) Security, built in at the very high level associated with AWS. The ShakeCast user base continues to expand and broaden. For example, Caltrans, the prototypical ShakeCast user and development supporter, has been providing guidance to other DOTs on the use of the National Bridge Inventory (NBI) database to implement fully-functional ShakeCast systems in their states. A long-term goal underway is to further "connect the DOTs" via a Transportation Pooled Fund (TPF) with participating state DOTs. We also review some of the many other users and uses of ShakeCast. Lastly, on the hazard input front, we detail related ShakeMap improvements and ongoing advancements in estimating the likelihood of shaking-induced secondary hazards at structures, facilities, bridges, and along roadways due to landslides and liquefaction, and implemented within the ShakeCast framework.

Conference Paper↗

USGS1995

A capture-recapture survival analysis model for radio-tagged animals

In recent years, survival analysis of radio-tagged animals has developed using methods based on the Kaplan-Meier method used in medical and engineering applications (Pollock et al., 1989a,b). An important assumption of this approach is that all tagged animals with a functioning radio can be relocated at each sampling time with probability 1. This assumption may not always be reasonable in practice. In this paper, we show how a general capture-recapture model can be derived which allows for some probability (less than one) for animals to be relocated. This model is not simply a Jolly-Seber model because it is possible to relocate both dead and live animals, unlike when traditional tagging is used. The model can also be viewed as a generalization of the Kaplan-Meier procedure, thus linking the Jolly-Seber and Kaplan-Meier approaches to survival estimation. We present maximum likelihood estimators and discuss testing between submodels. We also discuss model assumptions and their validity in practice. An example is presented based on canvasback data collected by G. M. Haramis of Patuxent Wildlife Research Center, Laurel, Maryland, USA.

Book chapter↗

USGS1948

Ground water hydraulics as a geophysical aid

The publication of the non-equilibrium formula in 1935 in a paper by Theis marked the opening of a new era in the analysis and understanding of the hydraulics of percolating ground waters. Through the past decade 9 an ever-increasing number of engineers and geologists have become familiar-with the application of this formula to practical problems of ground-water flow and have tested it in the field, against precise observations, under controlled conditions. Although the highly idealized aquifer assumed for the derivation of this formula is not of widespread occurrence in the field, we gain increasing confidence in the use of the Theis method as our backlog of proven data accumulates until we now look askance at test data which do not conform to this theory. In many cases, careful study of these anomalous data will reveal the means for estimating the degree or manner in which an observed aquifer diverges from the idealized aquifer.

Technical Report↗

USGS1984

Economics and appraisal of conventional oil and gas resources in the western Gulf of Mexico

The oil and gas industry frequently appraises undiscovered oil and gas resources on a regional basis to decide whether to start or continue exploration programs. The appraisals are of little value unless conditioned by estimates of the costs of finding and producing the resources. This paper presents an economic appraisal of undiscovered oil and presents an economic appraisal of undiscovered oil and gas resources in the western Gulf of Mexico. Also presented are a description of the model used to make the presented are a description of the model used to make the assessment, results of a sensitivity analysis, and a discussion of the implications of the results to the industry. The appraisal is shown to be relatively robust to changes in physical and engineering assumptions. At $30/bbl [$4.76/m ] oil equivalent (OE) and a 15 % required rate of return (ROR), commercial oil and gas discoveries are expected to amount to about 15 % of the 25.19 × 10 bbl [4 × 10 m ] OE contained in fields discovered before 1977 in the studied area. Hydrocarbons in future discoveries are expected to be 71 % nonassociated gas, 17 % crude oil, and 12 % other forms. Moreover, it will continue to be economically optimal to drill about three wildcat wells in the Miocene-Pliocene trend for every wildcat well drilled in the Pleistocene trend. Because the number of commercial discoveries was found to be quite sensitive to economic conditions, the analysis has important implications in terms of forecasting future industry drilling and other associated activities in the western Gulf of Mexico.

Journal of Petroleum Technology↗

USGS2020

Using NASA Earth observations and Google Earth Engine to map winter cover crop conservation performance in the Chesapeake Bay watershed

Winter cover crops such as barley, rye, and wheat help to improve soil structure by increasing porosity, aggregate stability, and organic matter, while reducing the loss of agricultural nutrients and sediments into waterways. The environmental performance of cover crops is affected by choice of species, planting date, planting method, nutrient inputs, temperature, and precipitation. The Maryland Department of Agriculture (MDA) oversees an agricultural cost-share program that provides farmers with funding to cover costs associated with planting winter cover crops, and the U.S. Geological Survey (USGS) and the U.S. Department of Agriculture-Agricultural Research Service (USDA-ARS) have partnered with the MDA to develop satellite remote sensing techniques for measuring cover crop performance. The MDA has developed the capacity to digitize field boundaries for all fields enrolled in their cover crop programs (>26,000 fields per year) to support a remote sensing performance analysis at a statewide scal,e and has requested assistance with the associated imagery processing from the National Aeronautics and Space Administration (NASA). Using the Google Earth Engine (GEE) cloud computing platform, scripts were developed to process Landsat 5/7/8 and Harmonized Sentinel-2 imagery to measure winter cover crop performance. We calibrated cover crop performance models using linear regression between satellite vegetation indices and USGS / USDA-ARS field sampling data collected on Maryland farms between 2006 and 2012 (1298 samples). Satellite-derived Normalized Difference Vegetation Index (NDVI) values showed significant correlation with the natural logarithm of cover crop biomass ( p ≤0.01, R 2 = 0.56) and with observed percent vegetative ground cover (p ≤0.01, R 2 = 0.68). The GEE scripts were used to composite seasonal maximum NDVI values for each enrolled cover crop field and calculate performance metrics for the winter and spring seasons of three enrollment years (2014–15, 2015–16, and 2017–18) for four Maryland counties. Results from winter 2017–18 demonstrate that rye and barley fields had higher biomass than wheat fields, and that early planting, along with planting methods that increase seed-soil contact, increased performance. The processing capabilities of GEE will support the MDA in scaling up remote sensing performance analysis statewide, providing information to evaluate the environmental outcomes associated with various agronomic management strategies. The tool can be modified for different seasonal cutoffs, utilize new sensors to capture phenology in winter and spring, and scale to larger regions for use in adaptive management of winter cover crops planted for environmental benefit.

Maryland↗

USGS1977

Mineralogical, chemical, and physical properties of the regolith overlying crystalline rocks, Fairfax County, Virginia: a preliminary report

Undisturbed cores of saprolite developed on crystalline rocks of the Piedmont Province in Fairfax County, Virginia have been obtained using a combination of Shelby tubes, Denison sampler, and modified diamond core-drilling. The principal purpose of the core study is to correlate variations in chemistry, mineralogy and texture with engineering properties throughout the weathering profile. Coring sites were chosen to obtain a maximum depth of weathering on diverse lithologies. The rocks investigated include pelitic schist, metagraywacke, granite, diabase and serpentinite. Four to twelve samples per core were selected, depending on thickness of 1) the weathering profile (from about 1 m in serpentinite to more than 30 m in pelitic schist) and on 2) megascopic changes in saprolite character for analysis of petrography, texture, clay mineralogy andd major element chemistry. Shear strength and compressibility were determined on corresponding segments of core. Standard penetration tests were performed adjacent to coring sites to evaluate engineering properties in situ. Geochemical changes of saprolite developed from each rock type follow predictable trends from fresh rock to soil profile, with relative Increases in Si, Ti, Al, Fe3+ and H20; variable K; and relative loss of Fe 2+, Mg, Ca, and Na. These variations are more pronounced in the weathering profiles over mafic and ultramafic rocks than metagraywacke. Clay minerals in granite, schist and metagraywacke saprolite are kaolinite, dioctahedral vermiculite, interlayered micavermiculite, and minor illite. Gibbsite is locally developed in near-surface samples of schist. Standard penetration test data for the upper 7 m of saprolite over schist and metagraywacke suggest alternations between stronger and weaker horizons than probably reflect variations in lithology including the presence of quartz lenses. Results for granite saprolite are most consistent but indicate lower strength. Shear strength increases fairly regularly downward in the weathering profile. The engineering behavior of diabase saprolite is controlled by a dense, plastic, near-surface clay layer (montmorillonite and kaolinite)overlying rock which is weathered to a granular state (grus), while engineering properties of serpentinite are determined by a very thin weathering profile.

Open-File Report↗

USGS2012

Sediment cores and chemistry for the Kootenai River White Sturgeon Habitat Restoration Project, Boundary County, Idaho

The Kootenai Tribe of Idaho, in cooperation with local, State, Federal, and Canadian agency co-managers and scientists, is assessing the feasibility of a Kootenai River habitat restoration project in Boundary County, Idaho. This project is oriented toward recovery of the endangered Kootenai River white sturgeon (Acipenser transmontanus) population, and simultaneously targets habitat-based recovery of other native river biota. Projects currently (2010) under consideration include modifying the channel and flood plain, installing in-stream structures, and creating wetlands to improve the physical and biological functions of the ecosystem. River restoration is a complex undertaking that requires a thorough understanding of the river. To assist in evaluating the feasibility of this endeavor, the U.S. Geological Survey collected and analyzed the physical and chemical nature of sediment cores collected at 24 locations in the river. Core depths ranged from 4.6 to 15.2 meters; 21 cores reached a depth of 15.2 meters. The sediment was screened for the presence of chemical constituents that could have harmful effects if released during restoration activities. The analysis shows that concentrations of harmful chemical constituents do not exceed guideline limits that were published by the U.S. Army Corps of Engineers in 2006.

Idaho↗

USGS1927

Large springs in the United States

What are the largest springs in the United States, how much water do they discharge, and what geologic conditions produce them are questions of much popular interest and considerable scientific and economic importance. Yet the information in regard to large springs has been so widely scattered and so difficult to interpret that most people have only very vague notions on the subject. The present paper is in a sense a by-product of a more comprehensive investigation of the origin, discharge, and quantity of ground water in the United States. It has, however, required, extensive search for data and critical analysis of the data that were obtained. The task would have been virtually impossible except for the hearty cooperation of the district engineers and other members of the water- resources branch of the Geological Survey, who are really coauthors of this paper. I wish to acknowledge especially the help of Kirk Bryan, G. C. Stevens, W. E. Hall, W. E. King, E. L. Williams, H. C. Beckman, C. E. Ellsworth, C. E. McCashin, C. G. Paulsen, W. G. Hoyt, H. T. Stearns, H. D. McGlashan, R. C. Briggs, F. F. Henshaw, W. A. Lamb, G. M. Hall, E. C. LaRue, and A. B. Purton

Water Supply Paper↗

USGS2009

Optical satellite data volcano monitoring: a multi-sensor rapid response system

In this chapter, the use of satellite remote sensing to monitor active geological processes is described. Specifically, threats posed by volcanic eruptions are briefly outlined, and essential monitoring requirements are discussed. As an application example, a collaborative, multi-agency operational volcano monitoring system in the north Pacific is highlighted with a focus on the 2007 eruption of Kliuchevskoi volcano, Russia. The data from this system have been used since 2004 to detect the onset of volcanic activity, support the emergency response to large eruptions, and assess the volcanic products produced following the eruption. The overall utility of such integrative assessments is also summarized. The work described in this chapter was originally funded through two National Aeronautics and Space Administration (NASA) Earth System Science research grants that focused on the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) instrument. A skilled team of volcanologists, geologists, satellite tasking experts, satellite ground system experts, system engineers and software developers collaborated to accomplish the objectives. The first project, Automation of the ASTER Emergency Data Acquisition Protocol for Scientific Analysis, Disaster Monitoring, and Preparedness , established the original collaborative research and monitoring program between the University of Pittsburgh (UP), the Alaska Volcano Observatory (AVO), the NASA Land Processes Distributed Active Archive Center (LP DAAC) at the U.S. Geological Survey (USGS) Earth Resources Observation and Science (EROS) Center, and affiliates on the ASTER Science Team at the Jet Propulsion Laboratory (JPL) as well as associates at the Earth Remote Sensing Data Analysis Center (ERSDAC) in Japan. This grant, completed in 2008, also allowed for detailed volcanic analyses and data validation during three separate summer field campaigns to Kamchatka Russia. The second project, Expansion and synergistic use of the ASTER Urgent Request Protocol (URP) for natural disaster monitoring and scientific analysis , has expanded the project to other volcanoes around the world and is in progress through 2011. The focus on ASTER data is due to the suitability of the sensor for natural disaster monitoring and the availability of data. The instrument has several unique facets that make it especially attractive for volcanic observations (Ramsey and Dehn, 2004). Specifically, ASTER routinely collects data at night, it has the ability to generate digital elevation models using stereo imaging, it can collect data in various gain states to minimize data saturation, it has a cross-track pointing capability for faster targeting, and it collects data up to ±85° latitude for better global coverage. As with any optical imaging-based remote sensing, the viewing conditions can negatively impact the data quality. This impact varies across the optical and thermal infrared wavelengths as well as being a function of the specific atmospheric window within a given wavelength region. Water vapor and cloud formation can obscure surface data in the visible and near infrared (VNIR)/shortwave infrared (SWIR) region due mainly to non-selective scattering of the incident photons. In the longer wavelengths of the thermal infrared (TIR), scattering is less of an issue, but heavy cloud cover can still obscure the ground due to atmospheric absorption. Thin clouds can be optically-transparent in the VNIR and TIR regions, but can cause errors in the extracted surface reflectance or derived surface temperatures. In regions prone to heavy cloud cover, optical remote sensing can be improved through increased temporal resolution. As more images are acquired in a given time period the chances of a clear image improve dramatically. The Advanced Very High Resolution Radiometer (AVHRR) routine monitoring, which commonly collects 4-6 images per day of any north Pacific volcano, takes advantage of this fact. The rapid response program described in this chapter also improves the temporal resolution of the ASTER instrument. ASTER has been acquiring images of volcanic eruptions since soon after its launch in December 1999. An early example included the observations of the large pyroclastic flow deposit emplaced at Bezymianny volcano in Kamchatka, Russia. The first images in March 2000, just weeks after the eruption, revealed the extent, composition, and cooling history of this large deposit and of the active lava dome (Ramsey and Dehn, 2004). The initial results from these early datasets spurred interest in using ASTER data for expanded volcano monitoring in the north Pacific. It also gave rise to the multi-year NASA-funded programs of rapid response scheduling and imaging throughout the Aleutian, Kamchatka and Kurile arcs. Since the formal establishment of the programs, the data have provided detailed descriptions of the eruptions of Augustine, Bezymianny, Kliuchevskoi and Sheveluch volcanoes over the past nine years (Wessels et al., in press; Carter et al., 2007, 2008; Ramsey et al., 2008; Rose and Ramsey, 2009). The initial research focus of this rapid response program was specifically on automating the ASTER sensor’s ability for targeted observational scheduling using the expedited data system. This urgent request protocol is one of the unique characteristics of ASTER. It provides a limited number of emergency observations, typically at a much-improved temporal resolution and quicker turnaround with data processing in the United States rather than in Japan. This can speed the reception of the processed data by several days to a week. The ongoing multi-agency research and operational collaboration has been highly successful. AVO serves as the primary source for status information on volcanic activity, working closely with the National Weather Service (NWS), Federal Aviation Administration (FAA), military and other state and federal emergency services. Collaboration with the Russian Institute of Volcanology and Seismology (IVS)/Kamchatka Volcanic Eruption Response Team (KVERT) is also maintained. Once a volcano is identified as having increased thermal output, ASTER is automatically tasked and the volcano is targeted at the next available opportunity. After the data are acquired, scientists at all the agencies have access to the images, with the primary science analysis carried out at the University of Pittsburgh and AVO. Results are disseminated to the responsible monitoring agencies and the global community through e-mail mailing lists.

Book chapter↗

USGS2003

Geothermal GIS coverage of the Great Basin, USA: Defining regional controls and favorable exploration terrains

A geographic information system (GIS) of geothermal resources, built last year for the state of Nevada, is being expanded to cover the Great Basin, USA. Data from that GIS is being made available to industry, other researchers, and the public via a web site at the Great Basin Center for Geothermal Energy, Reno, Nevada. That web site features a search engine, supports ArcExplorer?? for on-line map construction, and provides downloadable data layers in several formats. Though data collection continues, preliminary analysis has begun. Contour maps of geothermal temperatures, constructed using geothermometer temperatures calculated from a Great Basin geochemical database compiled by the Geo-Heat Center, reveal distinctive trends and patterns. As expected, magmatic-type and extensional-type geothermal systems have profoundly different associations, with magmatic-type systems following major tectonic boundaries, and extensional-type systems associating with regionally high heat flow, thin crust, active faulting, and high extensional strain rates. As described by earlier researchers, including Rowen and Wetlaufer (1981) and Koenig and McNitt (1983), high-temperature (> 100??C) geothermal systems appear to follow regional northeast trends, most conspicuously including the Humboldt structural zone in Nevada, the "Black Rock-Alvord Desert" trend in Oregon and Nevada, and the "Newcastle-Roosevelt" trend in Utah and Nevada. Weights-of-evidence analyses confirm a preference of high-temperature geothermal systems for young northeast-trending faults, but the distribution of geothermal systems correlates even better with high rates of crustal extension, as measured from global positioning system (GPS) stations in Nevada. A predictive map of geothermal potential based only on areas of high extensional strain rates and high heat flux does an excellent job of regionally predicting the location of most known geothermal systems in Nevada, and may prove useful in identifying blind systems.

Conference Paper↗

USGS1993

An engineering rock classification to evaluate seismic rock-fall susceptibility and its application to the Wasatch Front

Investigations of earthquakes world wide show that rock falls are the most abundant type of landslide that is triggered by earthquakes. An engineering classification originally used in tunnel design, known as the rock mass quality designation (Q), was modified for use in rating the susceptibility of rock slopes to seismically-induced failure. Analysis of rock-fall concentrations and Q-values for the 1980 earthquake sequence near Mammoth Lakes, California, defines a well-constrained upper bound that shows the number of rock falls per site decreases rapidly with increasing Q. Because of the similarities of lithology and slope between the Eastern Sierra Nevada Range near Mammoth Lakes and the Wasatch Front near Salt Lake City, Utah, the probabilities derived from analysis of the Mammoth Lakes region were used to predict rock-fall probabilities for rock slopes near Salt Lake City in response to a magnitude 6.0 earthquake. These predicted probabilities were then used to generalize zones of rock-fall susceptibility.

Bulletin of the Association of Engineering Geologi↗

USGS2000

Computer-model analysis of ground-water flow and simulated effects of contaminant remediation at Naval Weapons Industrial Reserve Plant, Dallas, Texas

In June 1993, the Department of the Navy, Southern Division Naval Facilities Engineering Command (SOUTHDIV), began a Resource Conservation and Recovery Act (RCRA) Facility Investigation (RFI) of the Naval Weapons Industrial Reserve Plant (NWIRP) in north-central Texas. The RFI has found trichloroethene, dichloroethene, vinyl chloride, as well as chromium, lead, and other metallic residuum in the shallow alluvial aquifer underlying NWIRP. These findings and the possibility of on-site or off-site migration of contaminants prompted the need for a ground-water-flow model of the NWIRP area. The resulting U.S. Geological Survey (USGS) model: (1) defines aquifer properties, (2) computes water budgets, (3) delineates major flowpaths, and (4) simulates hydrologic effects of remediation activity. In addition to assisting with particle-tracking analyses, the calibrated model could support solute-transport modeling as well as help evaluate the effects of potential corrective action. The USGS model simulates steadystate and transient conditions of ground-water flow within a single model layer. The alluvial aquifer is within fluvial terrace deposits of Pleistocene age, which unconformably overlie the relatively impermeable Eagle Ford Shale of Late Cretaceous age. Over small distances and short periods, finer grained parts of the aquifer are separated hydraulically; however, most of the aquifer is connected circuitously through randomly distributed coarser grained sediments. The top of the underlying Eagle Ford Shale, a regional confining unit, is assumed to be the effective lower limit of ground-water circulation and chemical contamination. The calibrated steady-state model reproduces long-term average water levels within +5.1 or –3.5 feet of those observed; the standard error of the estimate is 1.07 feet with a mean residual of 0.02 foot. Hydraulic conductivity values range from 0.75 to 7.5 feet per day, and average about 4 feet per day. Specific yield values range from 0.005 to 0.15 and average about 0.08. Simulated infiltration rates range from 0 to 2.5 inches per year, depending mostly on local patterns of ground cover. Computer simulation indicates that, as of December 31, 1998, remediation systems at NWIRP were removing 7,375 cubic feet of water per day from the alluvial aquifer, with 3,050 cubic feet per day coming from aquifer storage. The resulting drawdown prevented 1,800 cubic feet per day of ground water from discharging into Cottonwood Bay, as well as inducing another 1,325 cubic feet per day into the aquifer from the bay. An additional 1,200 cubic feet of water per day (compared to pre-remediation conditions) was prevented from discharging into the west lagoon, east lagoon, Mountain Creek Lake, and Mountain Creek swale. Particle-tracking simulations, assuming an aquifer porosity of 0.15, were made to delineate flowpath patterns, or contaminant “capture zones,” resulting from 2.5- and 5-year periods of remediation activity at NWIRP. The resulting flowlines indicate three such zones, or areas from which ground water is simulated to have been removed during July 1996–December 1998, as well as extended areas from which ground water would be removed during the next 2.5 years (January 1999– June 2001). Simulation indicates that, as of December 31, 1998, the recovery trench was intercepting about 827 cubic feet per day of ground water that—without the trench—would have discharged into Cottonwood Bay. During this time, the trench is simulated to have removed about 3,221 cubic feet per day of water from the aquifer, with about 934 cubic feet per day (29 percent) coming from the south (Cottonwood Bay) side of the trench.

Texas↗

USGS2007

Flood regionalization: A hybrid geographic and predictor-variable region-of-influence regression method

To facilitate estimation of streamflow characteristics at an ungauged site, hydrologists often define a region of influence containing gauged sites hydrologically similar to the estimation site. This region can be defined either in geographic space or in the space of the variables that are used to predict streamflow (predictor variables). These approaches are complementary, and a combination of the two may be superior to either. Here we propose a hybrid region-of-influence (HRoI) regression method that combines the two approaches. The new method was applied with streamflow records from 1,091 gauges in the southeastern United States to estimate the 50-year peak flow (Q50). The HRoI approach yielded lower root-mean-square estimation errors and produced fewer extreme errors than either the predictor-variable or geographic region-of-influence approaches. It is concluded, for Q50 in the study region, that similarity with respect to the basin characteristics considered (area, slope, and annual precipitation) is important, but incomplete, and that the consideration of geographic proximity of stations provides a useful surrogate for characteristics that are not included in the analysis. ?? 2007 ASCE.

Journal of Hydrologic Engineering↗

USGS2000

A method for producing digital probabilistic seismic landslide hazard maps

The 1994 Northridge, California, earthquake is the first earthquake for which we have all of the data sets needed to conduct a rigorous regional analysis of seismic slope instability. These data sets include: (1) a comprehensive inventory of triggered landslides, (2) about 200 strong-motion records of the mainshock, (3) 1:24 000-scale geologic mapping of the region, (4) extensive data on engineering properties of geologic units, and (5) high-resolution digital elevation models of the topography. All of these data sets have been digitized and rasterized at 10 m grid spacing using ARC/INFO GIS software on a UNIX computer. Combining these data sets in a dynamic model based on Newmark's permanent-deformation (sliding-block) analysis yields estimates of coseismic landslide displacement in each grid cell from the Northridge earthquake. The modeled displacements are then compared with the digital inventory of landslides triggered by the Northridge earthquake to construct a probability curve relating predicted displacement to probability of failure. This probability function can be applied to predict and map the spatial variability in failure probability in any ground-shaking conditions of interest. We anticipate that this mapping procedure will be used to construct seismic landslide hazard maps that will assist in emergency preparedness planning and in making rational decisions regarding development and construction in areas susceptible to seismic slope failure. ?? 2000 Elsevier Science B.V. All rights reserved.

Engineering Geology↗

USGS1998

A method for producing digital probabilistic seismic landslide hazard maps: An example from the Los Angeles, California, area

The 1994 Northridge, California, earthquake is the first earthquake for which we have all of the data sets needed to conduct a rigorous regional analysis of seismic slope instability. These data sets include (1) a comprehensive inventory of triggered landslides, (2) about 200 strong-motion records of the mainshock, (3) 1:24,000-scale geologic mapping of the region, (4) extensive data on engineering properties of geologic units, and (5) high-resolution digital elevation models of the topography. All of these data sets have been digitized and rasterized at 10-m grid spacing in the ARC/INFO GIS platform. Combining these data sets in a dynamic model based on Newmark's permanent-deformation (sliding-block) analysis yields estimates of coseismic landslide displacement in each grid cell from the Northridge earthquake. The modeled displacements are then compared with the digital inventory of landslides triggered by the Northridge earthquake to construct a probability curve relating predicted displacement to probability of failure. This probability function can be applied to predict and map the spatial variability in failure probability in any ground-shaking conditions of interest. We anticipate that this mapping procedure will be used to construct seismic landslide hazard maps that will assist in emergency preparedness planning and in making rational decisions regarding development and construction in areas susceptible to seismic slope failure.

California↗

USGS2011

Assessing power of large river fish monitoring programs to detect population changes: the Missouri River sturgeon example

In 2003, the US Army Corps of Engineers initiated the Pallid Sturgeon Population Assessment Program (PSPAP) to monitor pallid sturgeon and the fish community of the Missouri River. The power analysis of PSPAP presented here was conducted to guide sampling design and effort decisions. The PSPAP sampling design has a nested structure with multiple gear subsamples within a river bend. Power analyses were based on a normal linear mixed model, using a mixed cell means approach, with variance estimates from the original data. It was found that, at current effort levels, at least 20 years for pallid and 10 years for shovelnose sturgeon is needed to detect a 5% annual decline. Modified bootstrap simulations suggest power estimates from the original data are conservative due to excessive zero fish counts. In general, the approach presented is applicable to a wide array of animal monitoring programs.

Journal of Applied Ichthyology↗

USGS2021

The Everglades vulnerability analysis—Integrating ecological models and addressing uncertainty

The Everglades vulnerability analysis (EVA) is a project led by the U.S. Geological Survey in cooperation with the National Park Service and U.S. Army Corps of Engineers to accomplish one of the science goals of Restoration Coordination & Verification (RECOVER), a multiagency group responsible for providing scientific and technical evaluations and assessments for improving the ability of the Comprehensive Everglades Restoration Plan to restore, preserve, and protect the south Florida ecosystem while providing for the region’s other water-related needs. In 2016, RECOVER acknowledged the need for a tool that could synthesize the decades of Everglades ecosystem science and identify areas vulnerable to changing conditions on the landscape. The EVA tool answers this need through a landscape-scale modeling framework that provides annual responses and relative vulnerability for a suite of indicators of Everglades ecosystem health.

Florida↗

USGS2017

Assessment of adult pallid sturgeon fish condition, Lower Missouri River—Application of new information to the Missouri River Recovery Program

During spring 2015, Nebraska Game and Parks Commission (NGPC) biologists noted that pallid sturgeon (Scaphirhynchus albus) were in poor condition during sampling associated with the Pallid Sturgeon Population Assessment Project and NGPC’s annual pallid sturgeon broodstock collection effort. These observations prompted concerns that reduced fish condition could compromise reproductive health and population growth of pallid sturgeon. There was a further concern that compromised condition could possibly be linked to U.S. Army Corps of Engineers management actions and increase jeopardy to the species. An evaluation request was made to the Missouri River Recovery Program and the Effects Analysis Team was chartered to evaluate the issue. Data on all Missouri River pallid sturgeon captures were requested and received from the National Pallid Sturgeon Database. All data were examined for completeness and accuracy; 12,053 records of captures between 200 millimeters fork length (mm FL) and 1,200 mm FL were accepted. We analyzed condition using (1) the condition formula (Kn) from Shuman and others (2011); (2) a second Kn formulation derived from the 12,053 records (hereafter referred to as “Alternative Kn”); and (3) an analysis of covariance (ANCOVA) approach that did not rely on a Kn formulation. The Kn data were analyzed using group (average annual Kn) and individual (percentage in low, normal, and robust conditions) approaches. Using the Shuman Kn formulation, annual mean Kn was fairly static from 2005 to 2011 (although always higher in the upper basin), declined from 2012 to 2015, then remained either static (lower basin) or increasing (upper basin) in 2016. Under the Alternative Kn formulation, the upper basin showed no decline in Kn, whereas the lower basin displayed the same trend as the Shuman Kn formulation. Using both formulations, the individual approach revealed a more complex situation; at the same times and locations that there are fish in poor condition, there are nearby fish in normal or robust condition. The ANCOVA approach revealed that fish condition at size changed between 400 and 600 mm and that some of the apparent trend in low condition was caused by differences in sample size across the size range of the population (that is, greater catch of intermediate-sized fish compared to large fish). We examined basin, year, origin (hatchery compared to wild), segment, and size class for effects on condition and concluded that, since 2012, there has been an increase in the percentage of pallid sturgeon in low condition. There are basin, year, and segment effects; origin and size class do not seem to have an effect. The lower basin, in particular segment 9 (Platte River to Kansas River), had a high percentage of low-condition fish. Within the segment, there were bend-level effects, but the bend effect was not spatially contiguous. We concluded that existing data confirm concerns about declining fish condition, especially in the segments between Sioux City, Iowa, and Kansas City, Missouri. Although the evidence is strong that fish condition has been in decline from 2011 to 2015, additional analysis of individual fish histories may provide more confidence in this conclusion; such analysis was beyond the scope of this effort but is part of our recommendations. The most recent data in 2016 indicate that decline of condition may have leveled off; however, the length of record is insufficient to determine whether recent declines are within the background range of variation. We recommend that monitoring of fish condition should be increased and enhanced with additional health metrics. We also recommend that, should condition continue to decline, processes are deployed to bring low-condition adult fish into the hatchery to improve nutrition and condition. We could not determine the cause of declining fish condition with available data, but we compiled information on several dominant hypotheses in two main categories: inter- or intraspecific competition for resources and habitat conditions. Data are insufficient to indicate a specific causation or solution, and it is possible that multiple causes apply. We make recommendations for additional research that can be pursued to address uncertainties in trends in fish health as well as potential causes.

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