USGS Science⌕ Search

SEARCH · USGS Science

Results for “Current Climate Change Reports”

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

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

At least 289 records · Page 16Linked to original sources
USGS2013

Integrated carbon budget models for the Everglades terrestrial-coastal-oceanic gradient: Current status and needs for inter-site comparisons

Recent studies suggest that coastal ecosystems can bury significantly more C than tropical forests, indicating that continued coastal development and exposure to sea level rise and storms will have global biogeochemical consequences. The Florida Coastal Everglades Long Term Ecological Research (FCE LTER) site provides an excellent subtropical system for examining carbon (C) balance because of its exposure to historical changes in freshwater distribution and sea level rise and its history of significant long-term carbon-cycling studies. FCE LTER scientists used net ecosystem C balance and net ecosystem exchange data to estimate C budgets for riverine mangrove, freshwater marsh, and seagrass meadows, providing insights into the magnitude of C accumulation and lateral aquatic C transport. Rates of net C production in the riverine mangrove forest exceeded those reported for many tropical systems, including terrestrial forests, but there are considerable uncertainties around those estimates due to the high potential for gain and loss of C through aquatic fluxes. C production was approximately balanced between gain and loss in Everglades marshes; however, the contribution of periphyton increases uncertainty in these estimates. Moreover, while the approaches used for these initial estimates were informative, a resolved approach for addressing areas of uncertainty is critically needed for coastal wetland ecosystems. Once resolved, these C balance estimates, in conjunction with an understanding of drivers and key ecosystem feedbacks, can inform cross-system studies of ecosystem response to long-term changes in climate, hydrologic management, and other land use along coastlines

Florida↗
USGS2019

Natural resource condition assessment: Channel Islands National Park

The Natural Resource Condition Assessment (NRCA) Program aims to provide documentation about the current conditions of important Park natural resources through a spatially explicit, multidisciplinary synthesis of existing scientific data and knowledge. Findings from the NRCA will help Channel Islands National Park (CINP) managers to develop near-term management priorities. The central objectives of this assessment were to evaluate the current conditions and trends of key Park resources, identify important knowledge gaps, and determine key stressors and threats. Because a recent report provided an assessment of marine resources (Engle 2006), which constitute 50% of the park, this NRCA focused on terrestrial resources. For this NRCA, CINP resource managers identified that the greatest Park need was to know whether or not vegetation (primarily woody vegetation) is recovering on the Channel Islands and how this may be influencing recovery of the native terrestrial vertebrates. To address this, the CINP NRCA team evaluated the condition of island vegetation and vertebrate communities using both: 1) already available, summarized information from reports, theses, and journal articles and 2) new analyses of recently available, existing data collected on the islands. Descriptions of specific methods used to analyze available data by the NRCA team are provided within the assessment sections in Chapter 4 of this report. The Team used the Vital Signs indicators as identified by Fancy et al. (2009) for monitoring the condition of Natural Resources in U.S. National Parks. Using this framework, the focal study resource components were the five CINP islands, because these are the bio-geophysical resources of greatest interest to the CINP. Each of the islands has its own unique history of human impacts, ecological conditions, restoration efforts, and natural resource monitoring. The Team evaluated island scrub recovery by assessing changes over time in two metrics: 1) vegetation community structure (species composition, cover, and spatial extent), and 2) vertebrate abundance, relative to the reference condition of each island. The reference conditions for this NRCA were the particular island’s ecological state prior to European settlement or ranching, which represent the ecological state to which the NPS desires the park return. For each metric, the Team determined the Reference Conditions/Values, Current Condition, Trend, and Recovery Potential (based on a review of the literature and from the NRCA team’s analysis of newly available data), Threats and Stressors, Data Gaps, Overall Condition. A qualitative statement of overall current condition was created for each metric, after all data and literature relevant to the measures (i.e., vegetation and vertebrates) of each resource component (i.e., island) were reviewed and evaluated. All information gathered for this NRCA is available and managed by CINP, so that the compilation of resources would be available not only for the assessment team, but will be provided for future Park reference. Chapter 1 of this NRCA provides a descriptive background of NRCAs. Chapter 2 provides Park-wide natural resource background information, while Chapter 3 describes the overall methodological approach used in this assessment. Chapter 4 provides a detailed assessment of each island’s condition, which is then summarized Park-wide and for each island in Chapter 5. Based on both vegetation recovery and vertebrate population abundances, our assessment found Santa Cruz Island (SCI), Santa Rosa Island (SRI), San Miguel Island (SMI), and Anacapa Island (AI) to be, overall, in moderate condition and slowly recovering following the removal of non-native herbivores. The condition of Santa Barbara Island (SBI) is poor and remains in a state that is not likely to improve without assisted recovery by the Park. All islands have exhibited some level of native vegetation recovery, with most of the observed natural recovery occurring on SCI, SRI, SMI, and AI; very little recovery has occurred at present on SBI. Vegetation recovery is uneven across each island and largely limited to mesic areas, such as north-facing slopes. Areas that will likely require some assisted recovery efforts are those that are: at risk of erosion, isolated, lacking native seed banks, and plagued with high competition of non-native grasses and other invasives. Some plant communities, such as exposed upland vegetation on SRI, also have lower natural recovery potential and will likely require assisted recovery. The overall condition of the Park’s terrestrial island vertebrate species generally appears to be good and improving, with high potential for further recovery to reach pre-ranching era reference conditions. This is particularly true for vertebrates on SCI, SRI, and SMI. Although there are limited data for AI, the data that are available suggest that vertebrates on that island are in good condition and improving as well. However, the condition of SBI vertebrates is only moderate, with natural recovery potential being low, with many landbird species’ populations currently declining, extinct, or not improving. An overarching theme across the Park’s terrestrial island vertebrate populations is that many of them are in good condition because the particular animals are habitat generalists, so their population dynamics are not strongly tied to habitat conditions. However, those landbirds associated with riparian vegetation are not showing signs of recovery across the Park islands, and riparian areas appear to be one of the habitats with limited natural recovery potential on the islands. Overwhelmingly, the most critical data gap that emerged from our analysis was the lack of current vegetation maps for most of the islands (AI, SCI, SRI, SMI). The lack of this information made it difficult to assess spatial changes in island vegetation over time, and to relate those changes to observed changes in vertebrate species abundances. Therefore, we were limited in our spatial assessment of vegetation recovery for AI, SCI, SRI, and SMI, and were only able to relate the current vegetation with island landbird analysis for SBI. Another common theme across islands was the lack of information on best techniques for shrub reintroduction and recovery, and the success of invasive species removal and re-vegetation efforts. Abundance, distribution, and habitat affinities of reptiles and amphibians are poorly known for AI, SCI, SRI, and SMI, making it difficult to assess their population condition and trends, and their potential responses to shrub recovery. Mammal and landbird populations are reasonably well-sampled across most of the islands, but data are lacking for most vertebrates from AI, especially West and Middle AI where no vertebrate sampling occurs. The population status, cause of declines, and recovery needs are lacking for several landbird species across multiple islands, including loggerhead shrikes ( Lanius ludovicianus ssp.) on SCI and SRI, and Santa Cruz Island rufous crowned sparrows ( Aimophila ruficeps obscura ) on AI. Additionally, island song sparrows ( Melospiza melodia graminea ) remain extirpated on SBI and data are needed for assessing their recovery potential on the island. The potentially major threats facing the islands’ flora and fauna today are: areas of continued erosion, potential new non-native introductions, and climate change. The Park islands have already experienced warming over the last several decades due to human-induced climate change, and are projected to experience continued warming. These increasing stresses imposed by climate change may slow and inhibit natural recovery potentials for island fauna, and especially flora.

California↗
USGS2017

Centennial-scale reductions in nitrogen availability in temperate forests of the United States

Forests cover 30% of the terrestrial Earth surface and are a major component of the global carbon (C) cycle. Humans have doubled the amount of global reactive nitrogen (N), increasing deposition of N onto forests worldwide. However, other global changes—especially climate change and elevated atmospheric carbon dioxide concentrations—are increasing demand for N, the element limiting primary productivity in temperate forests, which could be reducing N availability. To determine the long-term, integrated effects of global changes on forest N cycling, we measured stable N isotopes in wood, a proxy for N supply relative to demand, on large spatial and temporal scales across the continental U.S.A. Here, we show that forest N availability has generally declined across much of the U.S. since at least 1850 C.E. with cool, wet forests demonstrating the greatest declines. Across sites, recent trajectories of N availability were independent of recent atmospheric N deposition rates, implying a minor role for modern N deposition on the trajectory of N status of North American forests. Our results demonstrate that current trends of global changes are likely to be consistent with forest oligotrophication into the foreseeable future, further constraining forest C fixation and potentially storage.

Scientific Reports↗
USGS2010

Conceptual understanding and groundwater quality of selected basin-fill aquifers in the Southwestern United States

The National Water-Quality Assessment (NAWQA) Program of the U.S. Geological Survey has been conducting a regional analysis of water quality in the principal aquifer systems in the southwestern United States (hereinafter, “Southwest”) since 2005. Part of the NAWQA Program, the objective of the Southwest Principal Aquifers (SWPA) study is to develop a better understanding of water quality in basin-fill aquifers in the region by synthesizing information from case studies of 15 basins into a common set of important natural and human-related factors found to affect groundwater quality. The synthesis consists of three major components: 1. Summary of current knowledge about the groundwater systems, and the status of, changes in, and influential factors affecting quality of groundwater in basin-fill aquifers in 15 basins previously studied by NAWQA (this report). 2. Development of a conceptual model of the primary natural and human-related factors commonly affecting groundwater quality, thereby building a regional understanding of the susceptibility and vulnerability of basin-fill aquifers to contaminants. 3. Development of statistical models that relate the concentration or occurrence of specific chemical constituents in groundwater to natural and human-related factors linked to the susceptibility and vulnerability of basin-fill aquifers to contamination. Basin-fill aquifers occur in about 200,000 mi 2 of the 410,000 mi 2 SWPA study area and are the primary source of groundwater supply for cities and agricultural communities. Four of the principal aquifers or aquifer systems of the United States are included in the basin-fill aquifers of the study area: (1) the Basin and Range basin-fill aquifers in California, Nevada, Utah, and Arizona; (2) the Rio Grande aquifer system in New Mexico and Colorado; (3) the California Coastal Basin aquifers; and (4) the Central Valley aquifer system in California. Because of the generally limited availability of surface-water supplies in the arid to semiarid climate, cultural and economic activities in the Southwest are particularly dependent on supplies of good-quality groundwater. Irrigation and public-supply withdrawals from basin-fill aquifers in the study area account for about one quarter of the total withdrawals from all aquifers in the United States. Many factors influence the quality of groundwater in the 15 case-study basins, but some common factors emerge from the basin summaries presented in this report. These factors include the chemical composition of the recharge water, consolidated rock geology and composition of aquifer materials derived from consolidated rock, and land and water use. The major water-quality issues in many of the developed case-study basins are increased concentrations of dissolved solids, nitrate, and VOCs in groundwater as a result of human activities. The information presented and the citations listed in this report serve as a resource for those interested in the groundwater-flow systems in the NAWQA case-study basins. The summaries of water-development history, hydrogeology, conceptual understanding of the groundwater system under both predevelopment and modern conditions, and effects of natural and human-related factors on groundwater quality presented in the sections on each basin also serve as a foundation for the synthesis and modeling phases of the SWPA regional study.

Arizona, California, Colorado, Nevada, New Mexico,↗
USGS2018

Assessing and communicating the impacts of climate change on the Southern California coast

Over the course of this and the next century, the combination of rising sea levels, severe storms, and coastal erosion will threaten the sustainability of coastal communities, development, and ecosystems as we currently know them. To clearly identify coastal vulnerabilities and develop appropriate adaptation strategies for projected increased levels of coastal flooding and erosion, coastal managers need user-friendly planning tools based on the best available climate and coastal science. In anticipation of these climate change impacts, many communities are in the early stages of climate change adaptation planning but lack the scientific information and tools to adequately address the potential impacts. In collaboration with leading scientists worldwide, the USGS designed the Coastal Storm Modeling System (CoSMoS) to assess the coastal impacts of climate change for the California coast, including the combination of sea level rise, storms, and coastal change. In this project, we directly address the needs of coastal resource managers in Southern California by integrating a vast range of global climate change projections and translate that information using sophisticated physical process models into planning-scale physical, ecological, and economic exposure, shoreline change, and impact assessments, all delivered in two simple, user-friendly, online tools. Our results show that by the end of the 21st century, over 250,000 residents and nearly $40 billion in building value across Southern California could be exposed to coastal flooding from storms, sea level rise, and coastal change. Results for the other major population center in California (the greater San Francisco Bay Area) are also available but not explicitly discussed in this report. Together, CoSMoS has now assessed the exposure of 95% of the 26 million coastal residents of the State (17 million in Southern California).

California↗
USGS2008

Geographic Names of Iceland's Glaciers: Historic and Modern

Climatic changes and resulting glacier fluctuations alter landscapes. In the past, such changes were noted by local residents who often documented them in historic annals; eventually, glacier variations were recorded on maps and scientific reports. In Iceland, 10 glacier place-names are to be found in Icelandic sagas, and one of Iceland's ice caps, Snaefellsjokull, appeared on maps of Iceland published in the 16th century. In the late 17th century, the first description of eight of Iceland's glaciers was written. Therefore, Iceland distinguishes itself in having a more than 300-year history of observations by Icelanders on its glaciers. A long-term collaboration between Oddur Sigurdsson and Richard S. Williams, Jr., led to the authorship of three books on the glaciers of Iceland. Much effort has been devoted to documenting historical glacier research and related nomenclature and to physical descriptions of Icelandic glaciers by Icelanders and other scientists from as far back as the Saga Age to recent (2008) times. The first book, Icelandic Ice Mountains, was published by the Icelandic Literary Society in 2004 in cooperation with the Icelandic Glaciological Society and the International Glaciological Society. Icelandic Ice Mountains was a glacier treatise written by Sveinn Palsson in 1795 and is the first English translation of this important scientific document. Icelandic Ice Mountains includes a Preface, including a summary of the history and facsimiles of page(s) from the original manuscript, a handwritten copy, and an 1815 manuscript (without maps and drawings) by Sveinn Palsson on the same subject which he wrote for Rev. Ebenezer Henderson; an Editor's Introduction; 82 figures, including facsimiles of Sveinn Palsson's original maps and perspective drawings, maps, and photographs to illustrate the text; a comprehensive Index of Geographic Place-Names and Other Names in the treatise; References, and 415 Endnotes. Professional Paper 1746 (this book) is the second of the three books; it is being published in both English and Icelandic editions. This book provides information about all named glaciers in Iceland, historic and modern. Descriptions, with geographic coordinates, and bibliographic citations to all glacier place-names on published maps, books, and scientific articles are included. Maps, oblique aerial photographs, ground photographs, and satellite images document each of the 269 modern named glaciers of Iceland. The third book, Glaciers of Iceland, is Chapter D of the 11-chapter [volume] U.S. Geological Survey Professional Paper 1386-A-K. Chapter D includes a 1:500,000-scale Map of the Glaciers of Iceland; it is a comprehensive historical and modern review and assessment of what is currently known about glaciers in Iceland's eight Regional Glacier Groups from a review of the scientific literature and from analysis of maps and remotely sensed data (ground, airborne, and satellite); topics include geology and geography, climate and climate variability, types of glaciers, history of glacier variation (including the 21 surge-type glaciers), and frequency and magnitude of volcanic and lacustrine jokulhlaups.

Professional Paper↗
USGS2022

Paralytic shellfish toxins associated with Arctic Tern mortalities in Alaska

Harmful algal blooms produce biotoxins that can injure or kill fish, wildlife, and humans. These blooms occur naturally but have intensified in many locations globally due to recent climatic changes, including ocean warming. Such changes are especially pronounced in northern regions, where the effects of paralytic shellfish toxins (PSTs) on marine wildlife are of growing concern. In Alaska, seabird mortality events have increased in frequency, magnitude, and duration since 2015 alongside anomalously high ocean temperatures. Although starvation has been implicated as the apparent cause of death in many of these die-offs, saxitoxin (STX) and other PSTs have been identified as possible contributing factors. Here, we describe a mortality event at a nesting colony of Arctic Terns ( Sterna paradisaea ) near Juneau, Alaska in 2019 and report elevated concentrations of PSTs in bird, forage fish, and mussel samples. Concentrations of STX and other PSTs in tern tissues (2.5–51.2 µg 100g −1 STX-equivalents [STX-eq]) were of similar magnitude to those reported from other PST-induced bird die-offs. We documented high PST concentrations in blue mussels (>11,000 µg 100g −1 STX-eq; Mytilus edulis spp.) collected from nearby beaches, as well as in forage fish (up to 494 µg 100g −1 STX-eq) retrieved from Arctic Tern nests, thereby providing direct evidence of PST exposure via the terns’ prey. At maximum concentrations measured in this study, a single 5 g Pacific Sand Lance ( Ammodytes personatus ) could exceed the median lethal STX dose (LD 50 ) currently estimated for birds, offering strong support for PSTs as a likely source of tern mortality. In addition to describing this localized bird mortality event, we used existing energetics data from adult and nestling Arctic Terns to calculate estimated cumulative daily PST exposure based on ecologically relevant concentrations in forage fish. Our estimates revealed potentially lethal levels of PST exposure even at relatively low (≤30 ug 100g −1 STX-eq) toxin concentrations in prey. These findings suggest that PSTs present a significant hazard to Arctic Terns and other northern seabirds and should be included in future investigations of avian mortality events as well as assessments of population health.

Alaska↗
USGS2016

Assessing wildlife benefits and carbon storage from restored and natural coastal marshes in the Nisqually River Delta: Determining marsh net ecosystem carbon balance

Working in partnership since 1996, the U.S. Fish and Wildlife Service and the Nisqually Indian Tribe have restored 902 acres of tidally influenced coastal marsh in the Nisqually River Delta (NRD), making it the largest estuary-restoration project in the Pacific Northwest to date. Marsh restoration increases the capacity of the estuary to support a diversity of wildlife species. Restoration also increases carbon (C) production of marsh plant communities that support food webs for wildlife and can help mitigate climate change through long-term C storage in marsh soils. In 2015, an interdisciplinary team of U.S. Geological Survey (USGS) researchers began to study the benefits of carbon for wetland wildlife and storage in the NRD. Our primary goals are (1) to identify the relative importance of the different carbon sources that support juvenile chinook ( Oncorhynchus tshawytscha ) food webs and contribute to current and historic peat formation, (2) to determine the net ecosystem carbon balance (NECB) in a reference marsh and a restoration marsh site, and (3) to model the sustainability of the reference and restoration marshes under projected sea-level rise conditions along with historical vegetation change. In this fact sheet, we focus on the main C sources and exchanges to determine NECB, including carbon dioxide (CO 2 ) uptake through plant photosynthesis, the loss of CO 2 through plant and soil respiration, emissions of methane (CH 4 ), and the lateral movement or leaching loss of C in tidal waters.

Washington↗
USGS2009

Hurricane Ike: Observations and analysis of coastal change

Understanding storm-induced coastal change and forecasting these changes require knowledge of the physical processes associated with the storm and the geomorphology of the impacted coastline. The primary physical processes of interest are the wind field, storm surge, and wave climate. Not only does wind cause direct damage to structures along the coast, but it is ultimately responsible for much of the energy that is transferred to the ocean and expressed as storm surge, mean currents, and large waves. Waves and currents are the processes most responsible for moving sediments in the coastal zone during extreme storm events. Storm surge, the rise in water level due to the wind, barometric pressure, and other factors, allows both waves and currents to attack parts of the coast not normally exposed to those processes. Coastal geomorphology, including shapes of the shoreline, beaches, and dunes, is equally important to the coastal change observed during extreme storm events. Relevant geomorphic variables include sand dune elevation, beach width, shoreline position, sediment grain size, and foreshore beach slope. These variables, in addition to hydrodynamic processes, can be used to predict coastal vulnerability to storms The U.S. Geological Survey's (USGS) National Assessment of Coastal Change Hazards Project (http://coastal.er.usgs.gov/hurricanes), strives to provide hazard information to those interested in the Nation's coastlines, including residents of coastal areas, government agencies responsible for coastal management, and coastal researchers. As part of the National Assessment, observations were collected to measure coastal changes associated with Hurricane Ike, which made landfall near Galveston, Texas, on September 13, 2008. Methods of observation included aerial photography and airborne topographic surveys. This report documents these data-collection efforts and presents qualitative and quantitative descriptions of hurricane-induced changes to the shoreline, beaches, dunes, and infrastructure in the region that was heavily impacted by Hurricane Ike.

Texas↗
USGS2012

Plague

Plague offers readers an overview of this highly complex disease caused by the bacteria Yersinia pestis . The history of the disease, as well as information about Yersinia pestis and its transmission by fleas, is described. The section Geographic Distribution presents areas of the world and United States where plague occurs most commonly in rodents and humans. Species Susceptibility describes infection and disease rates in rodents, humans, and other animals. Disease Ecology considers the complex relationship among rodents, domestic and wild animals, and humans and explores possible routes of transmission and maintenance of the organism in the environment. The effects of climate change, the potential for Y. pestis to be used as a bioweapon, and the impact of plague on conservation of wildlife are considered in Points to Ponder . Disease Prevention and Control outlines methods of prevention and treatment including vaccination for prairie dogs and black-footed ferrets. A glossary of technical terms is included. Tonie E. Rocke, the senior author and an epizootiologist at the USGS National Wildlife Health Center (NWHC), is a prominent researcher on oral vaccination of prairie dogs to prevent plague. She is currently working to transfer her success in the laboratory to the field to control plague in prairie dogs. Rachel C. Abbott, a biologist at the NWHC, is assisting Dr. Rocke in this process and will coordinate field trials of the vaccine. Milt Friend, first director of the NWHC, wrote the foreword. Plague is intended for scholars and the general public. The material is presented in a simple, straightforward manner that serves both audiences. Numerous illustrations and tables provide easily understood summaries of key points and information.

Circular↗
USGS1986

Review of the hydrologic data-collection network in the St. Joseph River basin, Indiana

The St. Joseph River Basin data-collection network in the St. Joseph River for streamflow, lake, ground water, and climatic stations was reviewed. The network review included only the 1700 sq mi part of the basin in Indiana. The streamflow network includes 11 continuous-record gaging stations and one partial-record station. Based on areal distribution, lake effect , contributing drainage area, and flow-record ratio, six of these stations can be used to describe regional hydrology. Gaging stations on lakes are used to collect long-term lake-level data on which to base legal lake levels, and to monitor lake-level fluctuations after legal levels are established. More hydrogeologic data are needed for determining the degree to which grouhd water affects lake levels. The current groundwater network comprises 15 observation wells and has four purposes: (1) to determine the interaction between groundwater and lakes; (2) to measure changes in groundwater levels near irrigation wells; (3) to measure water levels in wells at special purpose sites; and (4) to measure long-term changes in water levels in areas not affected by pumping. Seven wells near three lakes have provided sufficient information for correlating water levels in wells and lakes but are not adequate to quantify the effect of groundwater on lake levels. Water levels in five observation wells located in the vicinity of intensive irrigation are not noticeably affected by seasonal withdrawals. The National Weather Sevice operates eight climatic stations in the basin primarily to characterize regional climatic conditions and to aid in flood forecasting. The network meets network-density guidelines established by the World Meterological Organization for collection of precipitation and evaporation data but not guidelines suggested by the National Weather Service for density of precipitation gages in areas of significant convective rainfalls. (Author 's abstract)

Indiana↗
USGS1982

A field study of large-scale oscillation ripples in a very coarse-grained, high-energy marine environment

Monastery Beach, Carmel, California is a pocket beach that sits within 200 m of the head of Carmel Submarine Canyon. Coarse to very coarse sand covers both the beach and adjacent shelf; in the latter area incoming waves have shaped the sand into large oscillation ripples. The accessibility of this area and a variable wave climate produce a unique opportunity to study large-scale coarse-grained ripples in a high-energy environment. These ripples, which only occur in very coarse sand, form under the intense, wave-generated currents that exist during storm conditions. Once formed, these ripples do not significantly change under lower energy waves. On three separate occasions scuba divers measured ripples and collected sand samples from ripple crests near fixed reference stakes along three transects. Ripple wavelength and grain size decreased with an increase in water depth. Sediment sorting was best closest to the surf zone and poorest at the rim of Carmel Canyon. Cobbles and gravel observed in ripple troughs represent lag deposits. Carmel Canyon refracts waves approaching Monastery Beach such that wave energy is focused towards the northern and southern portions of the beach, leaving the central part of the beach lower in energy. This energy distribution causes spatial variations in the ripples and grain sizes with the shortest wavelengths and smallest grain sizes being in the central part of the shelf.

Open-File Report↗
USGS2019

Groundwater availability in the Ozark Plateaus aquifer system

Executive Summary The study described in this report, initiated by the U.S. Geological Survey in 2014, was designed to evaluate fresh groundwater resources within the Ozark Plateaus, central United States, as an area within a broader national assessment of groundwater availability. The goals of the Ozark study were to evaluate historical effects of human activities on water levels and groundwater availability, quantify groundwater resources now and under probable future pumping and climate conditions, and evaluate existing monitoring networks for their value in making better predictions of future groundwater resources. Previous studies include simulation of local-scale groundwater flow under varying temporal scales, or simulation of the regional system under steady-state conditions. While these studies are useful, particularly for the problem for which they were designed, there is a need to look at the larger regional system under transient conditions to fully evaluate the water resource over time. This study focused on multiple spatial and temporal scales to examine changes in groundwater pumping, storage, and water-level declines. The regional scale provides a broad view of the sources and demands on the system with time. The study area covers approximately 68,000 square miles in the central United States in parts of Missouri, Arkansas, Kansas, and Oklahoma and encompasses the Ozark Plateaus Physiographic Province (Ozark Plateaus), including the Salem Plateau, Springfield Plateau, and Boston Mountains. Groundwater is withdrawn from the Ozark Plateaus aquifer system (Ozark system) for public supply and for domestic, agriculture (including irrigation and aquaculture), livestock, and non-agricultural use (including industrial, thermoelectric power generation, mining, and commercial). The Ozark system provides an important drinking-water supply for people living in the Ozark Plateaus because public supply and domestic use combined constitute the largest groundwater use. Precipitation is the ultimate source of freshwater to the Ozark system; most rainfall occurs during April, May, and June, and precipitation increases generally from north to south across the study area. Groundwater use currently accounts for only 10 percent of the total water use in the areas overlying the Ozark system, but provides a critical drinking-water resource because public supply and domestic groundwater withdrawals are largely from groundwater resources. The 380 million gallons per day of groundwater withdrawn from the Ozark system in 2010 accounts for approximately 2 percent of recharge. Although groundwater use represents a small component of the hydrologic budget, because of low storage in aquifer units, cones of depression with steep water-level gradients can develop quickly around pumping centers. The amount of water entering and leaving the aquifer system from 1900 to about 1965 was relatively constant at a rate of about 13 billion gallons per day (Bgal/d). Much of this inflow of water is discharged through streams in the system to balance the hydrologic budget. Changes in storage over time (from outflows to inflows) reflect the large variability in recharge: if recharge decreases, water levels will decrease, resulting in less groundwater discharge to streams and more water released from aquifer storage. Conversely, when recharge increases, water levels increase, more groundwater discharges to streams, and aquifer storage is replenished. Although pumping generally increased from 1900 to 2016, it does not appear to correlate with the change in storage over the same time period. Regionally, simulated change in groundwater storage corresponds with changes in recharge, more so than with increases in pumping. Average recharge was 11.6 Bgal/d for the period 1900 to 2016. Recharge was generally above average from predevelopment to 1965, followed by a period of below-average recharge from 1965 to about 1980. Recharge remained consistently above average from 1980 to about 1988, after which there was a period of average or below-average recharge, reflected by a decline through the mid-2000s. The implications and potential effects of increased pumping and long-term climate change on the Ozark Plateaus hydrologic system and groundwater availability are a concern for communities and resource managers in the area. Pumping varies from year to year, but is generally expected to moderately increase with population, industrial, and agricultural needs. Most climate models predict warmer minimum and maximum air temperatures by midcentury in the Ozark Plateaus area, especially from midspring through early fall. Three scenarios were developed to simulate possible future conditions from 2016 to 2060 and assess the potential effects on the hydrologic system and availability of water resources. For each scenario, changes in water levels and hydrologic budget components were evaluated from predevelopment (1900) to present (2016) and 45 years into the future (2060). The baseline scenario represents an extension of the average (1996 to 2016) seasonal pumping and recharge values. The pumping scenario is an extension of the average (1996 to 2016) seasonal recharge values with increases in pumping following the historical trend for the period 2016–2060 of up to 120 percent of the 1996 to 2016 average seasonal pumping values. The general circulation model (GCM) scenario is an extension of the average (1996 to 2016) seasonal pumping values and variable recharge based on seasonal averages of soil water storage from a water-balance model using temperature and precipitation from multiple GCMs. The general patterns of water-level decline are similar for each scenario. The areas of water-level decline in southwest Missouri and northeast Oklahoma are only marginally different by 2060 from those of 2009. In one area south of Springfield, Mo., water-level declines are less in the baseline and GCM scenarios than in 2009. This may be the result of a transition from groundwater use to surface-water supplies for a larger percentage of the demand in the area. For all three scenarios, forecasted pumping, recharge, and aquifer properties play an important role in determining the uncertainty of water-level forecasts at 94 real-time observation wells. Simulated aquifer properties in the productive middle and lower Ozark aquifers and the St. Francois confining unit of the Ozark system contribute most to predictive uncertainty in water levels at approximately 35 percent of the real-time observation wells. Out of the 94 real-time observation wells, 82 are developed in the lower Ozark aquifer.

Arkansas, Kansas, Missouri, Oklahoma↗
USGS2002

Fate of carbon in Alaskan Landscapes Project: Database for soils from eddy covariance tower sites, Delta Junction, AK

Soils in Alaska, and in high latitude terrestrial ecosystems in general, contain significant amounts of organic carbon, most of which is believed to have accumulated since the start of the Holocene about 10 ky before present. High latitude soils are estimated to contain 30-40% of terrestrial soil carbon (Melillo et al., 1995; McGuire and Hobbie, 1997), or ~ 300-400 Gt C (Gt = 1015 g), which equals about half of the current atmospheric burden of carbon. Boreal forests in particular are estimated to have more soil carbon than any other terrestrial biome (Post et al., 1982; Chapin and Matthews, 1993). The relations among net primary production, soil carbon storage, recurrent fire disturbance, nutrients, the hydrologic cycle, permafrost and geomorphology are poorly understood in boreal forest. Fire disturbance has been suggested to play a key role in the interactions among the complex biogeochemical processes influencing carbon storage in boreal forest soils (Harden et al., 2000; Zhuang et al., 2002). There has been an observed increase in fire disturbance in North American boreal black spruce (Picea mariana) forests in recent decades (Murphy et al., 1999; Kasichke et al., 2000), concurrent with increases in Alaskan boreal and arctic surface temperatures and warming of permafrost (Osterkamp and Romanofsky, 1999). Understanding the role of fire in long term carbon storage and how recent changes in fire frequency and severity may influence future high latitude soil carbon pools is necessary for those working to understand or mitigate the effects of global climate change.

Alaska↗
USGS2010

U.S. Geological Survey activities related to American Indians and Alaska Natives: Fiscal years 2007 and 2008

In the late 1800s, John Wesley Powell, the second director of the U.S. Geological Survey (USGS), followed his interest in the tribes of the Great Basin and Colorado Plateau and studied their cultures, languages, and surroundings. From that early time, the USGS has recognized the importance of Native knowledge and living in harmony with nature as complements to the USGS mission to better understand the Earth. Combining traditional ecological knowledge with empirical studies allows the USGS and Native American governments, organizations, and people to increase their mutual understanding and respect for this land. The USGS is the earth and natural science bureau within the U.S. Department of the Interior (DOI) and is not responsible for regulations or land management. Climate change is a major current issue affecting Native lives and traditions throughout the United States. Climate projections for the coming century indicate an increasing probability for more frequent and more severe droughts in the Southwest, including the Navajo Nation. Erosion has claimed Native homes in Alaska. Fish have become inedible due to diseases that turn their flesh mushy. Native people who rely on or who are culturally sustained by hunting, fishing, and using local plants are living with climate change now. The traditional knowledge of Native peoples enriches and confirms the work of USGS scientists. The results are truly synergistic-greater than the sum of their parts. Traditional ecological knowledge is respected and increasingly used in USGS studies-when the holders of that knowledge choose to share it. The USGS respects the rights of Native people to maintain their patrimony of traditional ecological knowledge. The USGS studies can help Tribes, Native organizations, and natural resource professionals manage Native lands and resources with the best available unbiased data and information that can be added to their traditional knowledge. Wise Native leaders have noted that traditional ecological knowledge includes the connections between Earth and her denizens. From this perspective, it is the connections among these ?relatives? that needs to be nurtured. This perspective on nature is finding new adherents among Natives and non-Natives as understanding of climate change and other environmental conditions deepens. Although this report uses the term ?resources,? the USGS, through its interdisciplinary research, acknowledges the interconnectedness of the Earth and the things that live upon it.

Circular↗
USGS2013

A model for evaluating effects of climate, water availability, and water management on wetland impoundments--a case study on Bowdoin, Long Lake, and Sand Lake National Wildlife Refuges

Many wetland impoundments managed by the U.S. Fish and Wildlife Service (USFWS) National Wildlife Refuge System throughout the northern Great Plains rely on rivers as a primary water source. A large number of these impoundments currently are being stressed from changes in water supplies and quality, and these problems are forecast to worsen because of projected changes to climate and land use. For example, many managed wetlands in arid regions have become degraded owing to the long-term accumulation of salts and increased salinity associated with evapotranspiration. A primary goal of the USFWS is to provide aquatic habitats for a diversity of waterbirds; thus, wetland managers would benefit from a tool that facilitates evaluation of wetland habitat quality in response to current and anticipated impacts of altered hydrology and salt balances caused by factors such as climate change, water availability, and management actions. A spreadsheet model that simulates the overall water and salinity balance (WSB model) of managed wetland impoundments is presented. The WSB model depicts various habitat metrics, such as water depth, salinity, and surface areas (inundated, dry), which can be used to evaluate alternative management actions under various water-availability and climate scenarios. The WSB model uses widely available spreadsheet software, is relatively simple to use, relies on widely available inputs, and is readily adaptable to specific locations. The WSB model was validated using data from three National Wildlife Refuges with direct and indirect connections to water resources associated with rivers, and common data limitations are highlighted. The WSB model also was used to conduct simulations based on hypothetical climate and management scenarios to demonstrate the utility of the model for evaluating alternative management strategies and climate futures. The WSB model worked well across a range of National Wildlife Refuges and could be a valuable tool for USFWS staff when evaluating system state and management alternatives and establishing long-term goals and objectives.

Bowdoin National Wildlife Refuge;Long Lake Nationa↗
USGS2018

Southern Great Plains Rapid Ecoregional Assessment—Volume II. Species and assemblages

The Southern Great Plains Rapid Ecoregional Assessment was conducted in partnership with the Bureau of Land Management (BLM) and the Great Plains Landscape Conservation Cooperative. The overall goal of the Rapid Ecoregional Assessments (REAs) is to compile and synthesize regional datasets to facilitate evaluation of the cumulative effects of change agents on priority ecological communities and species. In particular, the REAs identify and map the distribution of communities and wildlife habitats at broad spatial extents and provide assessments of ecological conditions. The REAs also identify where and to what degree ecological resources are currently at risk from change agents, such as development, fire, invasive species, and climate change. The REAs can help managers identify and prioritize potential areas for conservation or restoration, assess cumulative effects as required by the National Environmental Policy Act, and inform landscape-level planning and management decisions for multiple uses of public lands. Management questions form the basis for the REA framework and were developed in conjunction with the BLM and other stakeholders. Conservation elements are communities and species that are of regional management concern. Core management questions relate to the key ecological attributes and change agents associated with each conservation element. Integrated management questions synthesize the results of the primary core management questions into overall landscape-level ranks for each conservation element. The ecological communities evaluated as conservation elements are shortgrass, mixed-grass, and sand prairies; all grasslands; riparian and nonplaya wetlands; playa wetlands and saline lakes; and prairie streams and rivers. Species and species assemblages evaluated are the freshwater mussel assemblage, Arkansas River shiner ( Notropis girardi ), ferruginous hawk ( Buteo regalis ), lesser prairie chicken ( Tympanuchus pallidicinctus ), snowy plover ( Charadrius nivosus ), mountain plover ( Charadrius montanus ), long-billed curlew ( Numenius americanus ), interior least tern ( Sternula antillarum athalassos ), burrowing owl ( Athene cunicularia ), black-tailed prairie dog ( Cynomys ludovicianus ), bat assemblage, swift fox ( Vulpes velox ), and mule deer ( Odocoileus hemionus ). The Southern Great Plains REA is summarized in a series of three reports and associated datasets. The pre-assessment report (available online at https://doi.org/10.3133/ofr20151003 ) summarizes the process used by the REA stakeholders to select management questions, conservation elements, and change agents. It also provides background information for each conservation element. Volume I of the Southern Great Plains REA report addresses the ecological communities (available online at https://doi.org/10.3133/ofr20171100 ). Volume II (this volume) addresses the species and species assemblages. All source and derived datasets used to produce the maps and graphs for REAs are available online at the BLM Landscape Approach Data Portal ( https://landscape.blm.gov/geoportal/catalog/REAs/REAs.page ).

Colorado, Kansas, Nebraska, New Mexico, Oklahoma, ↗
USGS2011

Simulating daily water temperatures of the Klamath River under dam removal and climate change scenarios

A one-dimensional daily averaged water temperature model was used to simulate Klamath River temperatures for two management alternatives under historical climate conditions and six future climate scenarios. The analysis was conducted for the Secretarial Determination on removal of four hydroelectric dams on the Klamath River. In 2012, the Secretary of the Interior will determine if dam removal and implementation of the Klamath Basin Restoration Agreement (KBRA) (Klamath Basin Restoration Agreement, 2010) will advance restoration of salmonid fisheries and is in the public interest. If the Secretary decides dam removal is appropriate, then the four dams are scheduled for removal in 2020. Water temperature simulations were conducted to compare the effect of two management alternatives: the no-action alternative where dams remain in place, and the action alternative where dam removal occurs in 2020 along with habitat restoration. Each management alternative was simulated under historical climate conditions (1961-2010) and six 50-year (2012-2061) climate scenarios. The model selected for the study, River Basin Model-10 (RBM10), was used to simulate water temperatures over a 253-mile reach of the Klamath River located in south-central Oregon and northern California. RBM10 uses a simple equilibrium flow model, assuming discharge in each river segment on each day is transmitted downstream instantaneously. The model uses a heat budget formulation to quantify heat flux at the air-water interface. Inputs for the heat budget were calculated from daily-mean meteorological data, including net shortwave solar radiation, net longwave atmospheric radiation, air temperature, wind speed, vapor pressure, and a psychrometric constant needed to calculate the Bowen ratio. The modeling domain was divided into nine reaches ranging in length from 10.8 to 42.4 miles, which were calibrated and validated separately with measured water temperature data collected irregularly from 1961 to 2010. Calibration root mean square errors of observed versus simulated water temperatures for the nine reaches ranged from 0.8 to 1.5 degrees C. Mean absolute errors ranged from 0.6 to 1.2 degrees C. For model validation, a k-fold cross-validation technique was used. Validation root mean square error and mean absolute error for the nine reaches ranged from 0.8 to 1.4 degrees C and 0.8 to 1.2 degrees C, respectively. Input data for the six future climate scenarios (2012-2061) were derived from historical hydrological and meteorological data and simulated meteorological output from five Global Circulation Models. Total Maximum Daily Loads or other regulatory processes that might reduce future water temperatures were not included in the simulations. Under the current climate conditions scenario, impacts of dam removal on water temperatures were greatest near Iron Gate Dam (near Yreka, California) and were attenuated in the lower reaches of the Klamath River. May and October simulated mean water temperatures increased and decreased by approximately 1-2 degrees C and 2-4 degrees C, respectively, downstream of Iron Gate Dam after dam removal. Dam removal also resulted in an earlier annual temperature cycle shift of 18 days, 5 days, and 2 days, near Iron Gate Dam, Scott River, and Trinity River, respectively. Although the magnitude of precipitation and air temperature change predicted by the five Global Circulation Models varied, all five models resulted in progressive incremental increases in water temperatures with each decade from 2012 to 2061. However, dam removal under KBRA appeared to delay the effects of climate change to some extent near Iron Gate Dam. With dam removal under KBRA, annual-mean water temperatures exceeded the 49-year historical mean temperature beginning in 2045; whereas with dams, annual-mean temperatures exceeded the historical mean beginning in 2025. Potential changes in seasonal water temperatures resulting from dam removal, with or without future climat

Open-File Report↗