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At least 919 records · Page 51Linked to original sources
USGS2014

Relationships between water and gas chemistry in mature coalbed methane reservoirs of the Black Warrior Basin

Water and gas chemistry in coalbed methane reservoirs of the Black Warrior Basin reflects a complex interplay among burial processes, basin hydrodynamics, thermogenesis, and late-stage microbial methanogenesis. These factors are all important considerations for developing production and water management strategies. Produced water ranges from nearly potable sodium-bicarbonate water to hypersaline sodium-chloride brine. The hydrodynamic framework of the basin is dominated by structurally controlled fresh-water plumes that formed by meteoric recharge along the southeastern margin of the basin. The produced water contains significant quantities of hydrocarbons and nitrogen compounds, and the produced gas appears to be of mixed thermogenic-biogenic origin. Late-stage microbial methanogenesis began following unroofing of the basin, and stable isotopes in the produced gas and in mineral cements indicate that late-stage methanogenesis occurred along a CO 2 -reduction metabolic pathway. Hydrocarbons, as well as small amounts of nitrate in the formation water, probably helped nourish the microbial consortia, which were apparently active in fresh to hypersaline water. The produced water contains NH 4 + and NH 3 , which correlate strongly with brine concentration and are interpreted to be derived from silicate minerals. Denitrification reactions may have generated some N 2 , which is the only major impurity in the coalbed gas. Carbon dioxide is a minor component of the produced gas, but significant quantities are dissolved in the formation water. Degradation of organic compounds, augmented by deionization of NH 4 + , may have been the principal sources of hydrogen facilitating late-stage CO 2 reduction.

Alabama↗
USGS2011

First description of autumn migration of Sooty Falcon Falco concolor from the United Arab Emirates to Madagascar using satellite telemetry

The movement and migration pattern of the 'Near Threatened' Sooty Falcon Falco concolor is poorly known. Sooty Falcons breed on the islands of the Arabian Gulf after arriving from their non-breeding areas that are mainly in Madagascar. In the first satellite tracking of the species we fitted a 9.5 g Argos solar powered transmitter on an adult breeding Sooty Falcon off the western coast of Abu Dhabi in the United Arab Emirates. The bird successfully undertook autumn migration to Madagascar, a known wintering area for the species. We document the Sooty Falcon's autumn migration route and stop-over sites. The adult Sooty Falcon initiated its migration at night and with tailwinds, and travelled mainly during daytime hours for 13 days over an inland route of more than 5,656 km. The three stop-over sites in East Africa were characterised by moderate to sparse shrub cover associated with potential sources of water. We discuss the migration pattern of the tracked bird in relation to importance of non-breeding areas for Sooty Falcons and recent declines in numbers in their breeding range.

Bird Conservation International↗
USGS2010

Environmental tolerance of an invasive riparian tree and its potential for continued spread in the southwestern US

Questions: Exotic plant invasion may be aided by facilitation and broad tolerance of environmental conditions, yet these processes are poorly understood in species-rich ecosystems such as riparian zones. In the southwestern United States (US) two plant species have invaded riparian zones: tamarisk (Tamarix ramosissima, T. chinensis, and their hybrids) and Russian olive (Elaeagnus angustifolia). We addressed the following questions: (1) is Russian olive able to tolerate drier and shadier conditions than cottonwood and tamarisk? (2) Can tamarisk and cottonwood facilitate Russian olive invasion? Location: Arid riparian zones, southwestern US. Methods: We analyzed riparian tree seedling requirements in a controlled experiment, performed empirical field studies, and analyzed stable oxygen isotopes to determine the water sources used by Russian olive. Results: Russian olive survival was significantly higher in dense shade and low moisture conditions than tamarisk and cottonwood. Field observations indicated Russian olive established where flooding cannot occur, and under dense canopies of tamarisk, cottonwood, and Russian olive. Tamarisk and native riparian plant species seedlings cannot establish in these dry, shaded habitats. Russian olive can rely on upper soil water until 15 years of age, before utilizing groundwater. Conclusions: We demonstrate that even though there is little evidence of facilitation by cottonwood and tamarisk, Russian olive is able to tolerate dense shade and low moisture conditions better than tamarisk and cottonwood. There is great potential for continued spread of Russian olive throughout the southwestern US because large areas of suitable habitat exist that are not yet inhabited by this species. ?? 2010 International Association for Vegetation Science.

Journal of Vegetation Science↗
USGS2006

Storm-induced redistribution of deepwater sediments in Lake Ontario

High-resolution seismic reflection profiles, side-scan sonar profiles, and surface sediment analyses for grain size (% sand, silt & clay), total organic carbon content, and carbonate content along shore-perpendicular transects offshore of Olcott and Rochester in Lake Ontario were utilized to investigate cm-thick sands or absence of deep-water postglacial sediments in water depths of 130 to 165 m. These deepwater sands were observed as each transect approached and occupied the "sills," identified by earlier researchers, between the three deepest basins of the lake. The results reveal thin (0 to 5-cm) postglacial sediments, lake floor lineations, and sand-rich, organic, and carbonate poor sediments at the deepwater sites (> 130 m) along both transects at depths significantly below wave base, epilimnetic currents, and internal wave activity. These sediments are anomalous compared to shallower sediments observed in this study and deeper sediments reported by earlier research, and are interpreted to indicate winnowing and resuspension of the postglacial muds. We hypothesize that the mid-lake confluence of the two-gyre surface current system set up by strong storm events extends down to the lake floor when the lake is isothermal, and resuspends and winnows lake floor sediment at these locations. Furthermore, we believe that sedimentation is more likely to be influenced by bottom currents at these at these sites than in the deeper basins because these sites are located on bathymetric highs between deeper depositional basins of the lake, and the bathymetric constriction may intensify any bottom current activity at these sites.

Journal of Great Lakes Research↗
USGS1987

Sanctuaries for lake trout in the Great Lakes

Populations of lake trout, severely depleted in Lake Superior and virtually extirpated from the other Great Lakes because of sea lamprey predation and intense fishing, are now maintained by annual plantings of hatchery-reared fish in Lakes Michigan, Huron, and Ontario and parts of Lake Superior. The extensive coastal areas of the Great Lakes and proximity to large populations resulted in fishing pressure on planted lake trout heavy enough to push annual mortality associated with sport and commercial fisheries well above the critical level needed to reestablish self-sustaining stocks. The interagency, international program for rehabilitating lake trout includes controlling sea lamprey abundance, stocking hatchery-reared lake trout, managing the catch, and establishing sanctuaries where harvest is prohibited. Three lake trout sanctuaries have been established in Lake Michigan: the Fox Island Sanctuary of 121, 500 ha, in the Chippewa-Ottawa Treaty fishing zone in the northern region of the lake; the Milwaukee Reef Sanctuary of 160, 000 ha in midlake, in boundary waters of Michigan and Wisconsin; and Julian's Reef Sanctuary of 6, 500 ha, in Illinois waters. In northern Lake Huron, Drummond Island Sanctuary of 55, 000 ha is two thirds in Indian treaty-ceded waters in Michigan and one third in Ontario waters of Canada. A second sanctuary, Six Fathom Bank-Yankee Reef Sanctuary, in central Lake Huron contains 168, 000 ha. Sanctuary status for the Canadian areas remains to be approved by the Provincial government. In Lake Superior, sanctuaries protect the spawning grounds of Gull Island Shoal (70, 000 ha) and Devils Island Shoal (44, 000 ha) in Wisconsin's Apostle Island area. These seven sanctuaries, established by the several States and agreed upon by the States, Indian tribes, the U.S. Department of the Interior, and the Province of Ontario, contribute toward solving an interjurisdictional fishery problem.

Conference Paper↗
USGS2006

Future trends in transport and fate of diffuse contaminants in catchments, with special emphasis on stable isotope applications

A summary is provided of the first of a series of proposed Integrated Science Initiative workshops supported by the UNESCO International Hydrological Programme. The workshop brought together hydrologists, environmental chemists, microbiologists, stable isotope specialists and natural resource managers with the purpose of communicating new ideas on ways to assess microbial degradation processes and reactive transport at catchment scales. The focus was on diffuse contamination at catchment scales and the application of compound-specific isotope analysis (CSIA) in the assessment of biological degradation processes of agrochemicals. Major outcomes were identifying the linkage between water residence time distribution and rates of contaminant degradation, identifying the need for better information on compound specific microbial degradation isotope fractionation factors and the potential of CSIA in identifying key degradative processes. In the natural resource management context, a framework was developed where CSIA techniques were identified as practically unique in their capacity to serve as distributed integrating indicators of process across a range of scales (micro to diffuse) of relevance to the problem of diffuse pollution assessment. Copyright ?? 2006 John Wiley & Sons, Ltd.

Hydrological Processes↗
USGS2007

Pre-eruption recharge of the Bishop magma system

The 650 km 3 rhyolitic Bishop Tuff (eastern California, USA), which is stratigraphically zoned with respect to temperatures of mineral equilibration, reflects a corresponding thermal gradient in the source magma chamber. Consistent with previous work, application of the new TitaniQ (Ti-in-quartz) thermometer to quartz phenocryst rims documents an ∼100 °C temperature increase with chamber depth at the time of eruption. Application of TitaniQ to quartz phenocryst cores, however, reveals lower temperatures and an earlier gradient that was less steep, with temperature increasing with depth by only ∼30 °C. In many late-erupted crystals, sharp boundaries that separate low-temperature cores from high-temperature rims cut internal cathodoluminescent growth zoning, indicating partial phenocryst dissolution prior to crystallization of the high-temperature rims. Rimward jumps in Ti concentration across these boundaries are too abrupt (e.g., 40 ppm across a distance of <10 µm) to have survived magmatic temperatures for more than ∼100 yr. We interpret these observations to indicate heating-induced partial dissolution of quartz, followed by growth of high-temperature rims (made possible by lowering of water activity due to addition of CO 2 ) within 100 yr of the climactic 760 ka eruption. Hot mafic melts injected into deeper parts of the magma system were the likely source of heat and CO 2 , raising the possibility that eruption and caldera collapse owe their origin to a recharge event.

California↗
USGS2001

Geologic Maps of the Dardanus Sulcus (Jg-6), Misharu (Jg-10), Nabu (Jg-11), and Namtar (Jg-14) Quadrangles of Ganymede

Ganymede is the largest (~5,200 km diameter) of the Jovian satellites. Surficial features on Ganymede, as recorded by the Voyager 1 and 2 spacecraft (Smith and others, 1979a; 1979b), indicate a complex history of crustal formation. Several episodes of crustal modification led to the formation of curvilinear systems of furrows in dark terrain, the emplacement of light materials, and the creation of grooves in light terrain. Prior to exploration of the Jovian system by spacecraft, Earth-based observations established that the surface of Ganymede is dominated by water ice with various admixtures of fine silicate (rock) material (Pilcher and others, 1972; Sill and Clark, 1982). No agreement yet exists as to the amount of water in the near surface material; early estimates based on spectral reflectance data suggested that half the surface was covered by nearly pure water ice, whereas later studies by Clark (1981) indicated that up to 95% of the surface could be water ice and still be consistent with spectroscopic data. The Pioneer encounters with the Jovian system in 1973 and 1974 confirmed that Ganymede was made up of patches of light and dark terrain but did not have the spatial resolution needed to determine the percent cover of water ice, or geologic relations of surface materials. Not until the Voyager encounters was the surface seen with sufficient detail to enable geologic mapping. On the basis of albedo contrasts, surface morphology, crater density, and superposition relations, geologic mapping was done using principles and techniques that have been applied to the Earth, Moon, and other terrestrial planets (Wilhelms, 1972). Considerable uncertainty exists in applying such methods to bodies having icy crusts, as the internal processes that produce their surface configurations are poorly understood, and the resolution of the Voyager images is barely sufficient to show the detail required to interpret structural and stratigraphic relations. With the exception of the extreme southeastern portion of the Namtar quadrangle (Jg- 14), all images used for mapping were taken by Voyager 1. At the time of encounter, the eastern portion of the Misharu (Jg–10) and Namtar quadrangles were near the terminator, making it difficult to distinguish albedo variations best seen at high sun angles. The western quadrangles were imaged at resolutions of 2–5 km/pixel (Batson and others, 1980) from an oblique angle, so albedo variations can be seen, but topography and morphology are not well expressed in the images.

IMAP↗
USGS2003

Hydrological response to earthquakes in the Haibara well, central Japan - II. Possible mechanism inferred from time-varying hydraulic properties

28 coseismic groundwater level decreases have been observed at the Haibara well, Shizuoka prefecture, central Japan, from 1981 to 1997. These groundwater level changes cannot be explained as the poroelastic response to coseismic static strain. We use the atmospheric pressure and tidal responses of the well, rock properties measured on core samples from the same formation and pumping test results to characterize the hydraulic and mechanical properties of the aquifer. The responses of the Haibara well to the M2 Earth tide constituent and to atmospheric pressure have varied over time. In particular, increasing amplitude and decreasing phase lags were observed after the 1993 pumping test, as well as after earthquakes that caused coseismic water level changes. The tidal response, together with the surface load efficiency derived from the atmospheric pressure response, is used to estimate the mechanical properties of the aquifer. The largest amplitude of the M2 constituent, 2.2 mm, is small enough to imply that pore fluid in this system is approximately twice as compressible as water, possibly due to the presence of a small amount of exsolved gas. Diffusion of a coseismic pressure drop near the well could account for the observed time histories of the water level changes. The time histories of the water level drops are well matched by the decay of a coseismic pressure drop at least 80 m away from the well. Removal of a small amount of gas from the formation in that location might in turn explain the coseismic pressure drops.

Geophysical Journal International↗
USGS1995

Synthesis of natural flows at selected sites in and near the Milk River basin, Montana, 1928-89

Natural monthly streamflows were synthesized for the years 1928-89 at 2 sites in the St. Mary River Basin and 11 sites in the Milk River Basin in north- central Montana. The sites are represented as nodes in a streamflow accounting model being developed by the Bureau of Reclamation for the Milk River Basin. Recorded flows at most sites have been affected by human activities, including reservoir storage and irrigation diversions. The flows at the model nodes were corrected for the effects of these activities to obtain synthesized flows. The synthesized flows at nodes with seasonal and short-term records were extended using a statistical technique. The methods of synthesis varied, depending on upstream activities and information available. Flows at sites in the St. Mary River Basin and at the Milk River at Eastern Crossing of International Boundary pre- viously had been synthesized. The flows at mainstem sites downstream from the Milk River at Eastern Crossing were synthesized by adding synthesized natural runoff from intervening drainage areas to natural flows for Milk River at Eastern Crossing. Natural runoff from intervening drainage areas was estimated by multiplying recorded flows at selected index gaging stations on tributary streams by the ratio of the intervening drainage area to the combined drainage area of the index stations. The recorded flows for Milk River at Western Crossing of International Boundary and for Peoples Creek near Dodson, Montana, were assumed to be natural flows. The synthesized annual flows at the mouth of the Milk River compared favorably with the recorded flows near the mouth when the effects of upstream irrigation were considered.

Water-Resources Investigations Report↗
USGS2012

Thermal profiles for selected river reaches of the Methow and Chewuch Rivers, Washington, August 2011

Longitudinal profiles of near-streambed and near-surface temperatures were collected for selected reaches of the Methow and Chewuch Rivers, Washington, during August 2011 to facilitate development of a stream temperature model near the confluence of the Methow and Chewuch Rivers. Temperature was measured using a probe with an internal datalogger towed behind a watercraft moving downstream at ambient river velocity. For the Methow River, an additional temperature survey was completed using near-streambed and near-surface probes towed behind a second watercraft that traversed the channel to measure vertical and lateral temperature variability. All data were referenced to location that was concurrently measured with a Global Positioning System. Data are presented as Microsoft Excel® files consisting of date and time, water temperature, and Washington State Plane North easting and northing.

Washington↗
USGS2002

Rocky Mountain futures: An ecological perspective

The Rocky Mountain West is largely arid and steep, with ecological scars from past human use visible for hundreds of years. Just how damaging were the past 150 years of activity? How do current rates of disturbance compare with past mining, grazing, and water diversion activities? In the face of constant change, what constitutes a "natural" ecosystem? And can a high quality of life be achieved for both human and natural communities in this region. Rocky Mountain Futures presents a comprehensive and wide-ranging examination of the ecological consequences of past, current, and future human activities in the Rocky Mountain region of the United States and Canada. The book brings together 32 leading ecologists, geographers, and other scientists and researchers to present an objective assessment of the cumulative effects of human activity on the region's ecological health and to consider changes wrought by past human use. This combined view of past and present reveals where Rocky Mountain ecosystems are heading, and the authors project what the future holds based upon current economic and social trends and the patterns that emerge from them. The book: examines the biogeographic and paleoenvironmental setting and historical climate that have shaped Rocky Mountain ecosystems traces the direct human influences on landscapes and ecosystems over the past 150 years explores the cumulative effects of past, present, and projected future human activities on tundra, subalpine and montane forests, valleys, grasslands, and waters offers case studies that illustrate specific examples of human influence and current efforts to restore the environment Case studies focus on northern New Mexico; Summit County, Colorado; Flathead Valley, Montana; and Alberta, Canada. Among the contributors are Craig D. Allen, N. Thompson Hobbs, Linda L. Joyce, Robert E. Keane, David Schindler, Timothy R. Seastedt, David Theobald, Diana Tomback, William Travis, Cathy Whitlock, and Jack Stanford. The United Nations has proclaimed 2002 as the International Year of Mountains to increase international awareness of the global importance of mountain ecosystems. The case-based multidisciplinary approach of this book constitutes an important new model for understanding the implications of land-use practices and economic activity on mountains, and will serve a vital role in improving decisionmaking both in the Rocky Mountains and in other parts of the world that face similar challenges.

Book↗
USGS2009

Geologic Map of MTM 35337, 40337, and 45337 Quadrangles, Deuteronilus Mensae Region of Mars

Deuteronilus Mensae, first defined as an albedo feature at lat 35.0 deg N., long 5.0 deg E., by U.S. Geological Survey (USGS) and International Astronomical Union (IAU) nomenclature, is a gradational zone along the dichotomy boundary in the northern mid-latitudes of Mars. The boundary in this location includes the transition from the rugged cratered highlands of Arabia Terra to the northern lowland plains of Acidalia Planitia. Within Deuteronilus Mensae, polygonal mesas are prominent along with features diagnostic of Martian fretted terrain, including lobate debris aprons, lineated valley fill, and concentric crater fill. Lobate debris aprons, as well as the valley and crater fill deposits, are geomorphic indicators of ground ice, and their concentration in Deuteronilus Mensae is of great interest because of their potential association with Martian climate change. The paucity of impact craters on the surfaces of debris aprons and the presence of ice-cemented mantle material imply young (for example, Amazonian) surface ages that are consistent with recent climate change in this region of Mars. North of Deuteronilus Mensae are the northern lowlands, a potential depositional sink that may have had large standing bodies of water or an ocean in the past. The northern lowlands have elevations that are several kilometers below the ancient cratered highlands with significantly younger surface ages. The morphologic and topographic characteristics of the Deuteronilus Mensae region record a diverse geologic history, including significant modification of the ancient highland plateau and resurfacing of low-lying regions. Previous studies of this region have interpreted a complex array of geologic processes, including eolian, fluvial and glacial activity, coastal erosion, marine deposition, mass wasting, tectonic faulting, effusive volcanism, and hydrovolcanism. The origin and age of the Martian crustal dichotomy boundary are fundamental questions that remain unresolved at the present time. Several scenarios for its formation, including single and multiple large impact events, have been proposed and debated in the literature. Endogenic processes whereby crust is thinned by internal mantle convection and tectonic processes have also been proposed. Planetary accretion models and isotopic data from Martian meteorites suggest that the crust formed very early in Martian history. Using populations of quasi-circular depressions extracted from the topography of Mars, other studies suggest that the age difference between the highlands and lowlands could be ~100 m.y.. Furthermore, understanding the origin and age of the dichotomy boundary has been made more complicated due to significant erosion and deposition that have modified the boundary and its adjacent regions. The resulting diversity of terrains and features is likely a combined result of ancient and recent events. Detailed geologic analyses of dichotomy boundary zones are important for understanding the spatial and temporal variations in highland evolution. This information, and comparisons to other highland regions, can help elucidate the scale of potential environmental changes. Previous geomorphic and geologic mapping investigations of the Deuteronilus Mensae region have been completed at local to global scales. The regional geology was first mapped by Lucchitta (1978) at 1:5,000,000 scale using Mariner 9 data. This study concluded that high crater flux early in Martian history formed overlapping craters and basins that were later filled by voluminous lava flows that buried the impacted surface, creating the highlands. After this period of heavy bombardment, fluvial erosion of the highlands formed the canyons and valleys, followed by dissection that created the small mesas and buttes, and later, formation of the steep escarpment marking the present-day northern highland margin. After valley dissection, mass wasting and eolian processes caused lateral retreat of mesas and buttes

Scientific Investigations Map↗
USGS2009

Real-time decision support systems: the famine early warning system network

A multi-institutional partnership, the US Agency for International Development’s Famine Early Warning System Network (FEWS NET) provides routine monitoring of climatic, agricultural, market, and socioeconomic conditions in over 20 countries. FEWS NET supports and informs disaster relief decisions that impact millions of people and involve billions of dollars. In this chapter, we focus on some of FEWS NET’s hydrologic monitoring tools, with a specific emphasis on combining “low frequency” and “high frequency” assessment tools. Low frequency assessment tools, tied to water and food balance estimates, enable us to evaluate and map long-term tendencies in food security. High frequency assessments are supported by agrohydrologic models driven by satellite rainfall estimates, such as the Water Requirement Satisfaction Index (WRSI). Focusing on eastern Africa, we suggest that both these high and low frequency approaches are necessary to capture the interaction of slow variations in vulnerability and the relatively rapid onset of climatic shocks.

Book chapter↗
USGS2024

A framework for disaggregating remote-sensing cropland into rainfed and irrigated classes at continental scale

Agriculture consumes the largest share of freshwater globally; therefore, distinguishing between rainfed and irrigated croplands is essential for agricultural water management and food security. In this study, a framework incorporating the Budyko model was used to differentiate between rainfed and irrigated cropland areas in Africa for eight remote sensing landcover products and a high-confidence cropland map (HCCM). The HCCM was generated for calibration and validation of the crop partitioning framework as an alternative to individual cropland masks which exhibit high disagreement. The accuracy of the framework in partitioning the HCCM was evaluated using an independent validation dataset, yielding an overall accuracy rate of 73 %. The findings of this study indicate that out of the total area covered by the HCCM (2.36 million km 2 ), about 461,000 km 2 (19 %) is irrigated cropland. The partitioning framework was applied on eight landcover products, and the extent of irrigated areas varied between 19 % and 30 % of the total cropland area. The framework demonstrated high precision and specificity scores, indicating its effectiveness in correctly identifying irrigated areas while minimizing the misclassification of rainfed areas as irrigated. This study provides an enhanced understanding of rainfed and irrigation patterns across Africa, supporting efforts towards achieving sustainable and resilient agricultural systems. Consequently, the approach outlined expands on the suite of remote sensing landcover products that can be used for agricultural water studies in Africa by enabling the extraction of irrigated and rainfed cropland data from landcover products that do not have disaggregated cropland classes.

International Journal of Applied Earth Observation↗
USGS2009

The ecological limits of hydrologic alteration (ELOHA): A new framework for developing regional environmental flow standards

The flow regime is a primary determinant of the structure and function of aquatic and riparian ecosystems for streams and rivers. Hydrologic alteration has impaired riverine ecosystems on a global scale, and the pace and intensity of human development greatly exceeds the ability of scientists to assess the effects on a river-by-river basis. Current scientific understanding of hydrologic controls on riverine ecosystems and experience gained from individual river studies support development of environmental flow standards at the regional scale. 2. This paper presents a consensus view from a group of international scientists on a new framework for assessing environmental flow needs for many streams and rivers simultaneously to foster development and implementation of environmental flow standards at the regional scale. This framework, the ecological limits of hydrologic alteration (ELOHA), is a synthesis of a number of existing hydrologic techniques and environmental flow methods that are currently being used to various degrees and that can support comprehensive regional flow management. The flexible approach allows scientists, water-resource managers and stakeholders to analyse and synthesise available scientific information into ecologically based and socially acceptable goals and standards for management of environmental flows. 3. The ELOHA framework includes the synthesis of existing hydrologic and ecological databases from many rivers within a user-defined region to develop scientifically defensible and empirically testable relationships between flow alteration and ecological responses. These relationships serve as the basis for the societally driven process of developing regional flow standards. This is to be achieved by first using hydrologic modelling to build a 'hydrologic foundation' of baseline and current hydrographs for stream and river segments throughout the region. Second, using a set of ecologically relevant flow variables, river segments within the region are classified into a few distinctive flow regime types that are expected to have different ecological characteristics. These river types can be further subclassified according to important geomorphic features that define hydraulic habitat features. Third, the deviation of current-condition flows from baseline-condition flow is determined. Fourth, flow alteration-ecological response relationships are developed for each river type, based on a combination of existing hydroecological literature, expert knowledge and field studies across gradients of hydrologic alteration. 4. Scientific uncertainty will exist in the flow alteration-ecological response relationships, in part because of the confounding of hydrologic alteration with other important environmental determinants of river ecosystem condition (e.g. temperature). Application of the ELOHA framework should therefore occur in a consensus context where stakeholders and decision-makers explicitly evaluate acceptable risk as a balance between the perceived value of the ecological goals, the economic costs involved and the scientific uncertainties in functional relationships between ecological responses and flow alteration. 5. The ELOHA framework also should proceed in an adaptive management context, where collection of monitoring data or targeted field sampling data allows for testing of the proposed flow alteration-ecological response relationships. This empirical validation process allows for a fine-tuning of environmental flow management targets. The ELOHA framework can be used both to guide basic research in hydroecology and to further implementation of more comprehensive environmental flow management of freshwater sustainability on a global scale. ?? 2009 Blackwell Publishing Ltd.

Freshwater Biology↗
USGS2000

Publications of the Western Earth Surface Processes Team, 1999

The Western Earth Surfaces Processes Team (WESPT) of the U.S. Geological Survey, Geologic Division (USGS, GD), conducts geologic mapping and related topical earth- science studies in the western United States. This work is focused on areas where modern geologic maps and associated earth-science data are needed to address key societal and environmental issues such as ground-water quality, potential geologic hazards, and land-use decisions. Areas of primary emphasis currently include southern California, the San Francisco Bay region, and the Pacific Northwest. The team has its headquarters in Menlo Park, California, and maintains field offices at several other locations in the western United States. The results of research conducted by the WESPT are released to the public as a variety of databases, maps, text reports, and abstracts, both through the internal publication system of the USGS and in diverse external publications such as scientific journals and books. This report lists publications of the WESPT released in 1999 as well as additional 1997 and 1998 publications that were not included in the previous list (USGS Open-file Report 99-302). Most of the publications listed were authored or coauthored by WESPT staff. The list also includes some publications authored by non-USGS cooperators with the WESPT, as well as some authored by USGS staff outside the WESPT in cooperation with WESPT projects.

Open-File Report↗
USGS2011

Proceedings of the third USGS modeling conference, June 7-11, 2010, Broomfield, Colorado-Understanding and predicting for a changing world

The Third USGS Modeling Conference was held June 7th-11, 2010, in Broomfield, Colorado. The conference focused on the development and application of analytical and theoretical models and data availability that support managing the Nation's resources and help protect lives and property. Participants at the conference included scientists and managers from Department of the Interior (DOI) Bureaus; national and international Federal, State, and local agencies; academic institutions; and nongovernmental organizations. The conference was organized according to DOI priorities and the strategic directions of the USGS Science Strategy; the following themes were emphasized: (1) Understanding Ecosystems and Restoring America's Treasured Landscapes; (2) Climate Change and Impact; (3) New Energy Frontier and Minerals for America; (4) A National Hazards, Risk, and Resilience Assessment Program; (5) Role of Environment and Wildlife in Human Health; (6) A Water Census of the United States; and (7) New Methods of Investigation and Discovery. The conference theme-"Understanding and Predicting for a Changing World"-focused on the following goals: advance development and application of models; provide tools that address management issues; present state-of-the-art models ranging from individual phenomena to integrated systems; and foster a working community among scientists and managers.

Scientific Investigations Report↗