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USGS2013

Challenge theme 6: Natural hazard risks in the Borderlands: Chapter 8 in United States-Mexican Borderlands: Facing tomorrow's challenges through USGS science

Natural hazards such as earthquakes, landslides and debris flows, wildfires, hurricanes, and intense storm-induced flash floods threaten communities to varying degrees all along the United States–Mexican border. The U.S. Geological Survey (USGS) collaborates with Federal, State, and local agencies to minimize the effects of natural hazards by providing timely, unbiased science information to emergency response officials, resource managers, and the public to help reduce property damage, injury, and loss of life. The USGS often mobilizes response efforts during and after a natural hazard event to provide technical and scientific counsel on recovery and response, and it has a long history of deploying emergency response teams to major disasters in both domestic and international locations. This chapter describes the challenges of natural hazards in the United States–Mexican border region and the capabilities of the USGS in the fields of hazard research, monitoring, and assessment, as well as preventative mitigation and post-disaster response.

United States-Mexico Borderlands↗
USGS2023

Unrecorded tundra fires of the Arctic Slope, Alaska USA

Few fires are known to have burned the tundra of the Arctic Slope north of the Brooks Range in Alaska, USA. A total of 90 fires between 1969 and 2022 are known. Because fire has been rare, old burns can be detected by the traces of thermokarst and distinct vegetation they leave in otherwise uniform tundra, which are visible in aerial photograph archives. Several prehistoric tundra burns have been found in this way. Detection of tundra fires in this sparsely populated and remote area has been historically inconsistent and opportunistic, relying on reports by aircraft pilots. Fire reports have been logged into an administrative database which, out of necessity, has been used to scientifically evaluate changes in the fire regime. To improve the consistency of the record, we completed a systematic search of Landsat Collection 2 for the Brooks Range Foothills ecoregion over the period 1972–2022. We found 57 unrecorded tundra burns, about 41% of the total, which now numbers 138. Only 15% and 33% of all fires appear in MODIS and VIIRS satellite-borne thermal anomaly products, respectively. The fire frequency in the first 37 years of the record is 0.89 y −1 for natural ignitions that spread ≥10 ha. Frequency in the last 13 years is 2.5 y −1 , indicating a nearly three-fold increase in fire frequency.

Alaska↗
USGS2025

Seismic intensities, ground motions and basin amplification from the 2022 Mw 6.4 Ferndale, California intraslab earthquake

On December 20, 2022, a Mw 6.4 earthquake occurred at a depth of 18 km within the subducting Gorda plate in the Mendocino Triple Junction (MTJ), one of the most seismically active regions of the contiguous United States, causing widespread damage to local communities. Here we document the seismic intensities, ground motions, and basin amplification effects recorded by this earthquake across Humboldt County as part of an ongoing scientific effort to understand subduction zone earthquake hazards. Modified Mercalli Intensity (MMI) values from our post-earthquake field survey report shaking intensities as high as VIII (Severe). Strong ground motion data from 54 seismic stations were processed to calculate amplitude and frequency content parameters across Northern California. The maximum calculated geometric mean PGA and PGV are 1053 cm/s 2 and 52 cm/s (respectively), both recorded within the 3 km deep Eel River sedimentary basin. Comparisons with four published Ground Motion Prediction Equations indicate that PGA and PGV measurements align with expected attenuation-distance patterns for intraslab earthquakes of this nature. Within the Eel River Basin, ground motions for frequencies above 1 Hz are amplified, with respect to reference stations, by factors greater than 2. Our findings suggest that peak ground motions were mainly caused by sedimentary basin site-effects within the Eel River basin, although rupture directivity may have also increased ground motion amplitudes locally. While the Ferndale area is primarily impacted by shallow intraslab earthquakes, our results also raise questions about site-response and basin amplification hazards from a potential megathrust earthquake. The high seismicity rates of the southernmost Cascades call for stronger regional preparedness and improved strategies to mitigate the effects of such a large-scale disaster.

California↗
USGS1979

National Center tour guide

On behalf of each employee at the Geological Survey's National Center, I [H. William Menard, Director] extend a warm welcome to you during our Centennial Year. We hope that your visit to our headquarters will be a pleasant and rewarding experience. Our scientific research is directed towards helping to solve some of the critical environmental and natural resource problems that face our Nation today. We want you to see some aspects of this work, and we hope you will visit us again. As part of the Federal Government, we are deeply committed to the concept of public service. We are proud to serve you.

Virginia↗
USGS1990

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

Translation and transfer of complex scientific and engineering studies to nontechnical users are necessary for their use in reducing earthquake hazards in Utah. Three elements are needed for effective translation: likelihood of occurrence, location, and severity of potential hazards. Several examples of translated information for Utah are described and illustrated. Three elements are needed for effective transfer to nontechnical users: delivery, assistance, and encouragement. Numerous examples of transfer techniques in Utah are described and illustrated. The importance of evaluating and revising earthquake-hazard reduction programs and their components is emphasized. Over thirty evaluations of various natural-hazard reduction programs and techniques are introduced. This report was prepared for research managers, funding sources, and evaluators of the Utah earthquake-hazard reduction program who are concerned about effectiveness. It provides an overview of the Utah program for those researchers, engineers, planners, and decisionmakers --public and private -- who are committed to reducing human casualties, property damage, and interruptions of socioeconomic systems.

Utah↗
USGS2008

Water quality in the Arthur R. Marshall Loxahatchee National Wildlife Refuge — Trends and spatial characteristics of selected constituents, 1974-2004

Water quality in the interior marsh of the Arthur R. Marshall Loxahatchee National Wildlife Refuge is characterized by low concentrations of major ions, principally sodium and chloride, and is affected primarily by natural seasonal processes, such as evapotranspiration, rainfall, and biological activity. During the dry season, evapotranspiration exceeds precipitation, and specific conductance and conservative ion concentrations at marsh background sites typically increase by 40-70 percent between the end of the rainy season in September and the end of the dry season in May. Water enters the Refuge mainly from rainfall and perimeter canals. Water is pumped into the perimeter canals from large pumping stations, such as S-5A and S-6. In recent years, much of the water pumped into the Refuge passes through Stormwater Treatment Areas (STAs) before being released into the perimeter canals that surround the Refuge. Since 2001, water at S-6 has been diverted south toward STA-2, away from the Refuge perimeter canals. Water from S-5A and S-6 flows through agricultural lands with intense agricultural activity and typically contains relatively high concentrations of major ions, nutrients, and pesticides. Specific conductance, major-ion concentrations, and nutrient concentrations are an order of magnitude higher at S-5A and S-6 canal sites than at interior marsh sites. Water quality in the marsh bordering the canals can be affected substantially by the canal water, and these effects can extend several miles or more into the marsh depending on location in the Refuge and on the water level in the canals. As canal water flows into the marsh, processes such as uptake by periphyton and rooted vegetation and settling of particulate matter reduce the concentrations of nutrients to a greater extent than conservative ions such as chloride. Long- and short-term trends for specific conductance, chloride ion, sulfate ion, total phosphorus, and total nitrogen at five sites were evaluated primarily using an uncensored seasonal Kendall test with a water-level adjustment to reduce the effects of long wet or dry periods. Significant long-term trends (1974-2003) for specific conductance, chloride, total phosphorus, and total nitrogen at canal sites S-5A and S-6 were generally downward. Of the five sites, S-5A had the most pronounced decline for specific conductance at about -340 microsiemens per centimeter (?S/cm), followed by S-6 with a decline of about -280 ?S/cm. The two internal marsh sites, LOX8 and LOX13, had significant long-term trends in specific conductance of about +37 and -36 ?S/cm, respectively. Long-term trends for other constituents at the two internal marsh sites were generally small in magnitude or not measurable between 1978 and 2003. Marsh site LOX15 near the Hillsboro Canal showed no long-term trends, although specific conductance and sulfate concentration increased about 560 ?S/cm and 30 milligrams per liter, respectively, from 1998 to 2002. Site LOX15 is influenced strongly by intrusions of canal water, and increases in specific conductance and sulfate at this site coincided with increased canal-water inflows from STA-1W between 2001 and 2003. Median concentrations at LOX13 and S-5A were used to represent background and canal concentrations, respectively. Based on these values, the median chloride concentration at LOX15 indicates that the water is typically about 31 percent canal water and 69 percent ?natural? background water. Using median sulfate concentrations, similarly to chloride, the fraction of water at LOX15 was estimated to be 17 percent from canals and 83 percent from ?natural? background water. This finding suggests that in the low sulfate environment of the Refuge, sulfate is not conservative and only about half of the sulfate from canal water typically reaches LOX15; the rest presumably is removed by marsh plants, algae, and bottom sediments. Concentrations of pesticides and other organic compounds were measured

Florida↗
USGS2022

Contaminants of emerging concern in the Great Lakes: Science to inform management practices for protecting the health and integrity of wildlife populations from adverse effects: GLRI action plan I, focus area 1, goal 5

Executive Summary: Under Action Plan I (2010-2014) of the Great Lakes Restoration Initiative (GLRI), Federal and Academic partners began an investigation of the presence and distribution of contaminants of emerging concern (CECs) in the Great Lakes and potential impacts on fish and wildlife. The term CECs is applied to a broad range of chemicals that are currently in use but for which we currently lack good understanding of whether fish, wildlife, or humans are being exposed and/or whether negative health or environmental effects are expected if exposure occurs. Pharmaceuticals, personal care products, flame retardants, many current use pesticides, and poly- and perfluorinated chemicals are some well-known groups of CECs, but there is no definitive or comprehensive list that can be used to support the management of CECs to reduce impacts on the Great Lakes ecosystem. Four overarching goals were identified for this collaborative investigation: 1. Evaluate the sources, occurrence, and distribution of CECs across the Great Lakes Basin. 2. Examine associations between the distribution of CECs and land-use patterns. 3. Review both scientific literature and field-generated data to determine the potential for CECs to cause adverse effects on Great Lakes fish and wildlife populations. 4. Develop efficient strategies to survey and/or monitor for threats that CECs may pose in order to take effective management actions before those threats evolve into large scale impacts on Great Lakes ecosystems or the services they provide. Achievement of these goals ensures progress towards Focus Area 1: Toxic Substances and Areas of Concern from GLRI Action Plan I, Goal 5: “ The health and integrity of wildlife populations and habitat are protected from adverse chemical and biological effects associated with the presence of toxic substances in the Great Lakes Basin ”. This large-scale research effort was comprised of individual and collaborative projects from multiple federal agencies and academic institutions, involving over 85 investigators, and overseen by the U.S. Environmental Protection Agency (EPA) Region 5, Great Lakes National Program Office. Partners include the United States Geological Survey, the National Oceanic and Atmospheric Administration, U.S. Fish and Wildlife Service, Saint Cloud State University, the U.S. EPA Office of Research and Development, and the U.S. Army Corps of Engineers. Key findings: 1. Contaminants of emerging concern were found throughout the monitored Great Lakes tributaries, but types and concentrations vary in association with regional land use. CECs were detected in nearly all samples collected. The type and concentration of the specific contaminants detected varied considerably among field sites and in association with land use type, such as urban, agricultural, wetland, 2 or forest. Contaminants were detected in the water column, sediment, and tissues of all species surveyed in the current work (mussels, aquatic insects, fish, and insect-eating birds). 2. There were over 20 contaminants for which CEC concentrations approached or exceeded those reported to cause toxicity in laboratory experiments. This was based on detection in water, sediments and or biota at one or more field sites. These contaminants represent compounds that warrant further investigation and monitoring with respect to potential impacts in certain areas of the Great Lakes basin. Based on the present investigation, compounds of greatest concern include: polycyclic aromatic hydrocarbons, associated with oil-based products and combustion of organic matter; atrazine, an herbicide; dichlorvos, an insecticide; and ibuprofen and venlafaxine, both pharmaceuticals. 3. Results suggest that mixtures of CECs presently found in most Great Lakes tributary locations surveyed may elicit subtle biological effects, but likely are not, alone, causing obvious detriment to current communities of fish and wildlife. CECs detected in the Great Lakes were associated with subtle biological effects like changes in gene expression, altered circulating glucose, etc. in both wild-caught and laboratory-reared organisms. These effects were generally not indicative of reproductive failure or mortality. However, the effects may have more serious implications when combined with other sources of stress like habitat degradation, changing climate conditions, and competition with invasive species. Due to limited historical data, it is unknown whether severe CEC-related impacts have already affected aquatic communities in waterbodies that have received long-term inputs of these contaminants. Likewise, under Action Plan I, biological effects were not necessarily evaluated at the sites where CEC concentrations exceeding laboratory toxicity thresholds were detected. As a result, strategic, ongoing surveillance and monitoring of CECs is warranted. This collaborative investigation resulted in new tools, approaches, and data that can be used to inform and support the management of CECs to reduce their impacts on Great Lakes natural resources. The following products of this research effort are available through https://communities.geoplatform.gov/glri/ or by contacting the investigators (see technical chapters found in Appendices A-F): 1. Database of CEC occurrence and concentrations in US tributary streams. The database includes CEC detections in water, sediment, and fish and wildlife tissues, and represents the most comprehensive survey of CECs in the Great Lakes Region. 2. Synopses of results and key findings. Integrated summaries of results, conclusions, and management implications of the CEC research are available through reports, topical fact sheets, and presentations. 3. Technical publications: This collaborative research effort has resulted in over 50 peer-reviewed publications, agency reports, and data releases that can be of use to resource managers, the scientific community, and members of the public. 4. Innovative tools. Innovative monitoring devices, sampling equipment, conceptual frameworks, and software applications were developed over the course of this 3 research. These tools are transferable to stakeholders via internet accessibility or via specifications, instructions, and demonstration detailed in technical publications. Hypotheses to guide CECs research under Action Plan II. Findings from 2010-2014 were used to guide further research in 2015-2018 for basin-wide surveillance of CECs and for sites warranting further study of potential biological impacts of CECs. Additional surveillance included both evaluation of additional classes of contaminants and expanded lists for chemical classes shown to be of greatest concern. Mixtures of some of the most frequently detected contaminants were also tested in laboratory studies to understand whether long term exposures to multiple contaminants may result in effects not evident from uncontrolled, short-term field experiments.

Great Lakes↗
USGS2022

An introduction to current climate projections and their use in climate impacts research

Using climate projections to evaluate future climate impacts and their associated risks requires a background knowledge of the nature of climate change, use of climate models to develop future projections, and knowledge of how to address climate scenario uncertainty. This chapter provides an overview of climate and climate change, some of the foundational climate science that underlies current climate change assessments, and a brief introduction to climate models and climate scenario uncertainty. Global projections of temperature and precipitation changes from the recent Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6) and a brief comparison to the prior assessment (AR5) are provided. The main sources of uncertainty in these projections include climate variability, climate model differences and treatment of scientific knowledge gaps, and greenhouse gas (GHG) emissions. When projections are downscaled to local resolution, downscaling is an additional source of uncertainty. These uncertainties can be incorporated in assessments of climate impacts by choosing a range of scenarios that directly address the sources of uncertainty. Evaluating the likelihood of a given climate impact on animal health or management strategies requires consideration of the main sources of climate projection uncertainties. Adaptation requires consideration of global-to-regional contexts of climate changes and impacts, but also adaptive capacity.

Book chapter↗
USGS2023

The value of scientific information — An overview

Introduction The U.S. Geological Survey (USGS) provides reliable science, data, information, and models (hereafter collectively referred to as “information”) to describe and understand the Earth. This information is used to minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect quality of life. USGS science informs public and private decisions, operations, and risk management in all major United States economic sectors, as defined by the Bureau of Economic Analysis, and provides critical information for natural resource and natural hazard management and stewardship decisions. Understanding the value of scientific information supports applications of USGS science in land- and water-management decisions, and better informs the public about the return on investment of USGS programs. USGS economists, social scientists, and physical scientists are engaged in collaborative efforts to advance methods to estimate the value of information (VOI) produced by the USGS. These efforts involve collaborating with an international community to develop and refine estimation methods, establish best practices to determine VOI, develop a study repository, and conduct projects to assess the VOI of specific information products and their application. This report focuses on economic valuation conducted by USGS specifically, although the methodology has much broader applicability within the U.S. government, academia, and beyond. Noneconomic valuation techniques for assessing the VOI also exist but are not addressed in this report.

Open-File Report↗
USGS2020

Modeling Escherichia coli in the Missouri River near Omaha, Nebraska, 2012–16

The city of Omaha, Nebraska, has a combined sewer system in some areas of the city. In Omaha, Nebr., a moderate amount of rainfall will lead to the combination of stormwater and untreated sewage or wastewater being discharged directly into the Missouri River and Papillion Creek and is called a combined sewer overflow (CSO) event. In 2009, the city of Omaha began the implementation of their Long Term Control Plan (LTCP) to mitigate the effects of CSOs on the Missouri River and Papillion Creek. As part of the LTCP, the city partnered with the U.S. Geological Survey (USGS) in 2012 to begin monitoring in the Missouri River. Since 2012, monthly discrete water-quality samples for many constituents have been collected from the Missouri River at four sites. At 3 of the 4 sites, water quality has been monitored continuously for selected constituents and physical properties. These discrete water-quality samples and continuous water-quality monitoring data (from July 2012 to 2020) have been collected to better understand the water quality of the Missouri River, how it is changing with time, how it changes upstream from the city of Omaha to downstream, and how it varies during base-flow conditions and during periods of runoff. The purpose of this report is to document the development of Escherichia coli ( E. coli ) concentration models for these four Missouri River sites. Analysis was completed using the first 5 years of data (through 2016) to determine if the current approach is sufficient to meet future analysis goals and to understand if proposed models such as Load Estimator (LOADEST) models will be able to represent water-quality changes in the Missouri River. Multiple linear regression models were developed to estimate E. coli concentration using LOADEST as implemented in the rloadest package in the R statistical software program. A set of explanatory variables, including streamflow and streamflow anomalies, precipitation, information about CSOs, and continuous water quality, were evaluated for potential inclusion in regression models. The best model at Missouri River at NP Dodge Park at Omaha, Nebr. (USGS station 412126095565201; hereafter “NP Dodge”) included basin explanatory variables of upstream antecedent precipitation index measured at Tekamah, Nebr.; decimal time; season; and turbidity. The best model at Missouri River at Freedom Park Omaha, Nebr. (USGS station 411636095535401; hereafter “Freedom Park”) included the same explanatory variables as the NP Dodge model with the addition of turbidity anomalies and flow anomalies. The best models at the two downstream sites (Missouri River near Council Bluffs, Iowa, USGS station 06610505 and Missouri River near La Platte, Nebr., USGS station 410333095530101) included the same explanatory variables as the Freedom Park model with the addition of local antecedent precipitation index as measured at Eppley Airport in Omaha, Nebr., and additional turbidity and flow anomalies. The final selected models were the best models given our modeling design constraint in which explanatory variables included in the model for the upstream site were included in the downstream models. Explanatory variables currently (2020) being collected and included in the selected models through 2016 explained 64–75 percent of the variability of E. coli concentration in the Missouri River. Explaining 64–75 percent of the variability might be considered low when working with physical constituents (total nitrogen or sediment), but with the natural variability of biological constituents such as E. coli , the uncertainty of E. coli laboratory measurements, and the added complexity of modeling in a large drainage basin with multiple sources, these results are adequate and indicate that the explanatory variables being collected and models such as LOADEST can represent water-quality changes in the Missouri River for E. coli concentration from 2012 to 2016.

Nebraska↗
USGS2005

The fishes of Hot Springs National Park, Arkansas, 2003

Fish communities were sampled from eight sites within Hot Springs National Park. Fish were collected by seining and electrofishing during base-flow periods in July and October 2003. All individuals were identified to species. More than 1,020 individuals were collected, representing 24 species. The number of species collected at the sites ranged from 5 to 19. Central stoneroller, orangebelly darter, and longear sunfish were among the more abundant fish species at most sites. These species are typical of small streams in this area. An expected species list incorrectly listed 35 species because of incorrect species range or habitat requirements. Upon revising this list, the inventory yielded 24 of the 51 expected species (47 percent). No species collected in 2003 were federally-listed threatened or endangered species. However, two species collected at Hot Springs National Park may be of special interest to National Park Service managers and others. The Ouachita madtom is endemic to the Ouachita Mountains and is listed as a species of special concern by the Arkansas Natural Heritage Commission. The grass carp, which is a native of eastern Asia, is present in Ricks Pond; one individual was collected and no other grass carp were observed. The introduction of grass carp into the United States is a controversial issue because of possible (but undocumented) harmful effects on native species and habitats.

Scientific Investigations Report↗
USGS2020

Low-flow characteristics of streams from Wailua to Hanapēpē, Kauaʻi, Hawaiʻi

The purpose of this study is to characterize streamflow availability under natural (unregulated) low-flow conditions for streams in southeast Kaua‘i, Hawai‘i. The nine main study-area basins, from north to south, include Wailua River, Hanamā‘ulu, Nāwiliwili, Pūʻali, Hulēʻia, Waikomo, Lāwaʻi, and Wahiawa Streams, and Hanapēpē River. The results of this study can be used by water managers to develop technically sound instream-flow standards for the study-area streams. Low-flow characteristics for natural streamflow conditions were represented by flow-duration discharges that are equaled or exceeded between 95 and 50 percent of the time. Short-term continuous-record stream-gaging stations that monitored low flows on Waiahi and right branch Lāwaʻi Streams were established to serve as potential index stations for partial-record sites in the study area. Continuous-record stream-gaging station on Hanapēpē River monitored natural flow during calendar year 2017 and the streamflow record during that period was used to estimate low-flow characteristics at the station. Partial-record sites were established on 3 main streams and 15 tributary streams, upstream from existing surface-water diversions. Low-flow characteristics were determined using historical and current streamflow data from continuous-record stream-gaging stations and miscellaneous sites, as well as additional data collected as part of this study. Low-flow-duration discharges for the following streams were estimated for the 59-year base period (water years 1961–2019) using two record-augmentation techniques: right branch ʻŌpaekaʻa Stream, North Fork Wailua River, north and south fork Waikoko Streams, ‘Ili‘ili‘ula Stream, north and south fork Hanamāʻulu Streams, Kamo‘oloa Stream, Pāohia Stream, Ku‘ia Stream, Lāwa‘i Stream, Wahiawa Stream, and Hanapēpē River. The 95-percent flow-duration discharges (Q 95 ) ranged from 0.018 to 42 cubic feet per second (ft 3 /s). The 50-percent flow-duration discharges (Q 50 ) ranged from 1.1 to 69 ft 3 /s. Upper-bound estimates of low-flow duration discharges at partial-record sites on south fork Hanamāʻulu, Hanamāʻulu tributary, ʻŌmaʻo, and Pōʻeleʻele Streams were estimated based on the highest discharges measured as part of this study during Q 95 to Q 50 flow conditions, which were 0.44, 0.40, 0.19, and 0.22 ft 3 /s, respectively. Measured discharges on Nāwiliwili, Pū‘ali, and left branch Wahiawa Streams do not correlate with data at any active long-term continuous-record stream-gaging stations (10 or more complete water years of natural-flow record) and therefore low-flow duration discharges could not be estimated. This study also estimated streamflow gains and losses using seepage-run discharge measurements in eight of the nine study basins (Pūʻali Stream basin was excluded). A majority of the streams gained flow downstream from the uppermost diversions. Measured seepage-gain rates ranged between 0.03 and 24.3 ft 3 /s per mile of stream reach. Seepage gains are presumed to originate mainly from groundwater discharge in the Wailua River, Hanamā‘ulu Stream, Nāwiliwili Stream, Hulēʻia Stream, Lāwa‘i Stream, Wahiawa Stream, and Hanapēpē River basins. Under natural-flow conditions and flow conditions of the seepage runs, a majority of the study-area streams flow continuously from the mountains to the ocean. Where a stream discharges into a reservoir––Hanamā‘ulu and Wahiawa Streams––a dry reach may occur immediately downstream from the reservoir to the point of seepage gain in the stream.

Hawaii↗
USGS2012

The National Nonindigenous Aquatic Species Database

The U.S. Geological Survey (USGS) Nonindigenous Aquatic Species (NAS) Program maintains a database that monitors, records, and analyzes sightings of nonindigenous aquatic plant and animal species throughout the United States. The program is based at the USGS Wetland and Aquatic Research Center in Gainesville, Florida. The initiative to maintain scientific information on nationwide occurrences of nonindigenous aquatic species began with the Aquatic Nuisance Species Task Force, created by Congress in 1990 to provide timely information to natural resource managers. Since then, the NAS database has been a clearinghouse of information for confirmed sightings of nonindigenous, also known as nonnative, aquatic species throughout the Nation. The database is used to produce email alerts, maps, summary graphs, publications, and other information products to support natural resource managers.

Fact Sheet↗
USGS2020

Citizen science collaboration with the U.S. Geological Survey in Alaska

Citizen science is science undertaken by the public, usually in collaboration with professional scientific institutions. It encourages citizens to tackle real-world scientific problems and augments traditional science by expanding the coverage of data collection and by reducing costs of fieldwork in remote locations. Information collected by volunteers enables us all to gain a deeper understanding of how the natural world works and how it is changing. The U.S. Geological Survey is a leading Federal agency in fostering citizen-science collaborations, and the examples in this publication show the value of those collaborations.

Alaska↗
USGS2011

Digital signal processing and interpretation of full waveform sonic log for well BP-3-USGS, Great Sand Dunes National Park and Preserve, Alamosa County, Colorado

Along the Great Sand Dunes National Park and Preserve boundary (fig. 1), 10 monitoring wells were drilled by the National Park Service in order to monitor water flow in an unconfined aquifer spanning the park boundary. Adjacent to the National Park Service monitoring well named Boundary Piezometer Well No. 3, or BP-3, the U.S. Geological Survey (USGS) drilled the BP-3-USGS well. This well was drilled from September 14 through 17, 2009, to a total depth of 99.4 meters (m) in order to acquire additional subsurface information. The BP-3-USGS well is located at lat 37 degrees 43'18.06' and long -105 degrees 43'39.30' at a surface elevation of 2,301 m. Approximately 23 m of core was recovered beginning at a depth of 18 m. Drill cuttings were also recovered. The wireline geophysical logs acquired in the well include natural gamma ray, borehole caliper, temperature, full waveform sonic, density, neutron, resistivity, and induction logs. The BP-3-USGS well is now plugged and abandoned. This report details the full waveform digital signal processing methodology and the formation compressional-wave velocities determined for the BP-3-USGS well. These velocity results are compared to several velocities that are commonly encountered in the subsurface. The density log is also discussed in context of these formation velocities.

Scientific Investigations Report↗
USGS2007

Land-Cover Change in the Southern Lake Tahoe Basin, California and Nevada, 1940-2002

The Lake Tahoe basin has been subject to significant landscape-altering human activity since the mid-1850s; in particular, widespread timber harvest from the 1850s to 1920s and urban development from the 1950s to the present. The consequences of changes such as impacted water quality, degraded biotic communities, and increased fire hazard resulting from modern activity have prompted rising levels of concern for the ecological integrity of the region. The goal of this project is to map, quantify, and describe the spatial and temporal distribution and variability of historical changes in land use and land cover in the southern Lake Tahoe basin for the period from 1940 to 2002 in an effort to establish an understanding of regional landscape change. This map shows areas of land-use/land-cover change in a 279-km2 portion of the Lake Tahoe basin identified using change-detection analysis of multitemporal land-use/land-cover datasets for four dates (1940, 1969, 1987, and 2002), which yielded three periods for analysis. Land use/land cover was mapped using manual (visual) interpretation techniques in a geographic information system (GIS) from multiple imagery sources: black-and-white digital orthophotos for 1940 and 1969, natural-color digital orthophotos for 1987, and IKONOS multispectral satellite imagery for 2002. The landscape was classified using a 0.4-hectare (1-acre) minimum mapping unit and a hierarchical classification system. Impervious-surface data was derived directly from the 2002 IKONOS imagery on a per-pixel basis using digital image processing and GIS data integration.

Scientific Investigations Map↗
USGS2007

Reconnaissance study of the hydrology of American Memorial Park, Island of Saipan, Commonwealth of the Northern Mariana Islands

American Memorial Park, a unit of the National Park Service on the Island of Saipan, includes among its features a 27-acre estuarine system that has become a rarity within the Commonwealth of the Northern Mariana Islands. The estuarine system's mosaic of marshy areas interspersed with emergent wetlands and mixed wet forests provides critical habitat for various migratory and resident waterfowl, including two Federally listed endangered species: the Marianas gallinule ( Gallinula chloropus guami ) and the nightingale reed warbler ( Acrocephalus luscinia ). With sensitivity to the park's ecologic assets and the uncertainty associated with locally rapid urbanization, a need to better understand the hydrology of American Memorial Park was recognized. To address that need, a reconnaissance study of the park was undertaken during August and September 2005. The goals of the study were (1) to describe the occurrence and salinity of surface and ground water within the park; (2) to develop a hydrologic model of the park area of the island, with emphasis on the 27-acre estuarine system; and (3) to identify additional data needed to further develop this model. With regard to surface water, three freshwater inputs to the park's natural wetland are possible: direct rainfall, seaward-flowing ground water, and overland flow. Direct rainfall, which is an important source of freshwater to the wetland, commonly exceeds evapotranspiration both seasonally and per storm. The seaward flow of ground water is likely to be a source of freshwater to the wetland because ground water generally has an upward vertical component in the nearshore environment. Overland flow upgradient of the park could potentially contribute a significant input of freshwater during periods of intense rainfall, but roads that flank the park's perimeter act as a barrier to surficial inflows. During the reconnaissance, four discrete bodies, or zones, of surface water were observed within the park's natural wetland. Conductivity within these surface-water zones typically ranged from 1,540 to 4,370 microsiemens per centimeter (µS/cm) at 25°C although values as low as 829 and as high as 8,750 µ S/cm were measured. As a result of these observations, the American Memorial Park wetland area meets the definition criteria of an estuarine system that is dominantly oligohaline. Conductivity was also measured in a constructed wetland that was built within the park to augment the storm-drainage infrastructure of the village of Garapan. Reverse-osmosis facilities, in operation at hotels adjacent to the park, have historically discharged highly saline wastewater into the storm-drainage system. This collective storm and wastewater flow is routed into the constructed wetland and from there into the ocean. The conductivity of water in the constructed wetland ranged from 45,000 to 62,500 µS/cm , exceeding nominal seawater values by as much as 25 percent, with the highest conductivities recorded near discharging storm drains. With regard to ground water, the reconnaissance included installation of a ground-water-monitoring network. Data collected from this network identified the presence of freshwater underlying the park and indicated that surface water is directly connected to ground water in the natural wetland because the water levels of both surface water and ground water directly varied with the tide. Conductivities of ground-water samples from wells in the monitoring network indicated that ground-water salinity was geographically related: conductivities were lower (801-2,490 (µS/cm) in surficially dry areas, intermediate (6,090-9,180 (µS/cm) in natural-wetland areas, and higher (18,250-27,700 (µS/cm) in areas adjacent to the constructed wetland and its associated ocean-discharge channel. Synoptic water-level surveys were made to enhance understanding of the spatial expression of the water table; they were scheduled to overlap with peak and trough tidal signals to enable limited characteri

Scientific Investigations Report↗
USGS2015

Water-quality trends in the Scituate reservoir drainage area, Rhode Island, 1983-2012

The Scituate Reservoir is the primary source of drinking water for more than 60 percent of the population of Rhode Island. Water-quality and streamflow data collected at 37 surface-water monitoring stations in the Scituate Reservoir drainage area, Rhode Island, from October 2001 through September 2012, water years (WYs) 2002-12, were analyzed to determine water-quality conditions and constituent loads in the drainage area. Trends in water quality, including physical properties and concentrations of constituents, were investigated for the same period and for a longer period from October 1982 through September 2012 (WYs 1983-2012). Water samples were collected and analyzed by the Providence Water Supply Board, the agency that manages the Scituate Reservoir. Streamflow data were collected by the U.S. Geological Survey. Median values and other summary statistics for pH, color, turbidity, alkalinity, chloride, nitrite, nitrate, total coliform bacteria, Escherichia coli ( E. coli ), and orthophosphate were calculated for WYs 2003-12 for all 37 monitoring stations. Instantaneous loads and yields (loads per unit area) of total coliform bacteria and E. coli , chloride, nitrite, nitrate, and orthophosphate were calculated for all sampling dates during WYs 2003-12 for 23 monitoring stations with streamflow data. Values of physical properties and concentrations of constituents were compared with State and Federal water-quality standards and guidelines and were related to streamflow, land-use characteristics, varying classes of timber operations, and impervious surface areas. Tributaries in the Scituate Reservoir drainage area for WYs 2003-12 were slightly acidic (median pH of all stations equal to 6.1) and contained low median concentrations of chloride (22 milligrams per liter [mg/L]), nitrate (0.01 mg/L as nitrogen), nitrite (0.001 mg/L as nitrogen), and orthophosphate (0.02 milligrams per liter as phosphorus [mg/L as P]). Turbidity and alkalinity values also were low with medians of 0.57 nephelometric turbidity units and 5.1 mg/L as calcium carbonate, respectively. Total coliform bacteria and E. coli were detected in most samples from all stations, but median concentrations were generally low-43 colony-forming units per 100 milliliters (mL) and 15 colony-forming units per 100 milliliters, respectively. Median values of several physical properties and median concentrations of several constituents correlated positively with the percentages of developed land and negatively with the percentages of forest cover in the drainage areas above the monitoring stations. Median concentrations of chloride correlated positively with the percentages of impervious land use in the subbasins of monitoring stations, likely reflecting the effects of deicing compounds applied to roadways during winter maintenance. Median concentrations of alkalinity also correlated positively with the percentage of impervious land use, which may be related to the deterioration of fabricated structures containing calcium carbonate. Median values of color correlated positively with the percentage of wetland area in the subbasins of monitoring stations, reflecting the natural sources of color in tributaries. Streamflows were negatively correlated with turbidity and concentrations of total coliform bacteria and E. coli, possibly reflecting seasonal patterns in which relatively high values of these properties and constituents occur during warmer low-flow conditions late in the water year. Similar seasonal patterns were observed for pH, alkalinity, and color. Negative correlations between concentrations of chloride and streamflow also were significant, indicating that deicing salts from roadways and other impervious surfaces that lack direct connection to the tributaries are likely infiltrating to the groundwater and discharging to some of the tributaries late in the water year. While salt-laden runoff directly enters some of the tributaries at roadway crossings, most of the roadway runoff infiltrates into the adjacent berms throughout the drainage area. Statistically significant correlations were not identified between various degrees of tree-canopy reduction caused by timber operations in the subbasins and median values or concentrations of water-quality properties. Loads and yields of chloride, nitrate, nitrite, orthophosphate, and bacteria varied at monitoring stations in the Scituate Reservoir drainage area in WYs 2003-12. Loads generally were greater at stations in the Barden Reservoir and the Regulating Reservoir Subbasins that have larger drainage areas than in subbasins with smaller drainage areas. Subbasin yields of fecal-indicator bacteria and orthophosphate generally were largest in the Westconnaug Reservoir Subbasin, and subbasin yields for chloride, nitrate, and nitrite were largest in the Moswansicut Reservoir Subbasin in the northeastern part of the drainage area. Upward trends in pH were identified for nearly half of the monitoring stations for WYs 1983-2012 and may reflect regional reductions in acid precipitation. Many upward trends in alkalinity also were identified for both the WYs 1983-2012 and for WYs 2003-12 periods and are likely related to the natural weathering of structures containing concrete or, in some cases, the application of lime or fertilizers on agriculture lands. Significant trends in chloride concentrations at most stations during WYs 1983-2012 were upward; however, results for WYs 2003-12 substantiate few significant upward trends and, in a few cases, downward trends were identified in several tributary drainage areas.

Rhode Island↗