USGS Science⌕ Search

SEARCH · USGS Science

Results for “Natural Resources Research”

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 1,351 records · Page 75Linked to original sources
USGS2020

Fundamental hydraulics of cross sections in natural rivers: Preliminary analysis of a large data set of acoustic doppler flow measurements

We have assembled a comprehensive and publicly accessible U.S. Geological Survey (USGS) streamflow measurement data set, called HYDRoSWOT, from a USGS National Water Information System archive of acoustic Doppler current profiler river discharge measurements collected from a wide range of rivers throughout the United States. The data set provides a wealth of information on the range of hydraulic characteristics of river cross sections in the United States. Preliminary exploration of the data set, filtered for quality control, indicates that rivers tend toward consistent and predictable forms as discharge increases. The ratio of maximum-to-mean depth is highly predictable and is remarkably consistent across all river sizes and discharges. Distributions of hydraulic characteristics provide a large-scale perspective on the general hydraulic characteristics of rivers. The data set affords the opportunity to analyze hydraulic relations for individual rivers as a function of stage, geomorphic setting, and energy environments and, combined with additional information contained in this data set, might yield predictive relations that could help constrain and parameterize river hydraulic models.

Water Resource Research↗
USGS1967

Swatara Creek basin of southeastern Pennsylvania: An evaluation of its hydrologic system

Local concentrations of population in the Swatara Creek basin of Pennsylvania find it necessary to store, transport, and treat water because local supplies are either deficient or have been contaminated by disposal of wastes in upstream areas. Water in the basin is available for the deficient areas and for dilution of the coal-mine drainage in the northern parts and the sewage wastes in the southern parts. Swatara Creek drains 576 square miles just east of Harrisburg, Pa., and is the largest tributary to the Susquehanna River from the north side below Harrisburg. It rises in the southern Pocono Mountains and flows southwestward across the Lebanon Plateau. On an average day Swatara Creek discharges more than 630 million gallons into the Susquehanna River at Middletown, Pa. In a year this amounts to about 23 inches of water over the entire basin and is the residual from an average annual precipitation of 45.5 inches. During an average year the flow in Swatara Creek from the upper third of the basin above Harper Tavern is always greater than 1,300 mgd (million gallons per day) for at least 15 days and is always greater than 25 mgd for at least 350 days. The daily streamflow from the basin averages 1.1 mgd per sq mi, but yields from different areas range from 0.97 to 1.22 mgd per sq mi. These variations are caused chiefly by differences in precipitation and land cover. The area of lowest yield is in the valleys west of Tremont, and the highest yields are in the Upper and Lower Little Swatara Creek subbasins. At high and medium stages the chemical character of the water in the streams is suitable for public and private supplies. At lower stages, defending on the areas and the amounts of contamination by coal-mine drainage and sewage pollution, the natural flow may require some treatment. At low stages the chemical characteristics of the natural flow not affected by man is almost identical with that of the ground water in the area drained by the stream. In general, the total dissolved solids range from about 25 to 400 parts per million and the hardness is as much as about 300 parts per million. The ground-water increment to the base flow of Swatara Creek averages about 240 mgd, or about 8.8 inches annually, for the basin. Generally, ground-water supplies in amounts of less than 0.5 mgd can be developed south of Blue Mountain. Supplies of several million gallons per day have been developed for industrial use from the permeable limestones in the south-central part of the basin. More intensive investigation in other parts of the basin would indicate areas where supplies of more than 0.5 mgd could be developed from properly spaced wells. The chemical character of water from wells depends largely on the host rock. In highly soluble rocks water contains large amount of dissolved solids; in more resistant rocks concentrations are lower. The chemical character of unpolluted ground water generally reflects the composition of the more readily soluble minerals in the local geologic environment. Areas contaminated by septic- tank effluent may have above normal amounts of nitrate and detergent products. Except where polluted, most ground water is suitable for public and industrial uses without extensive treatment. Sites for storage of surface water exist in the part of the basin lying in the valley and ridge area. As much as 30 to 40 percent of the annual flow could be impounded for release as low-flow augmentation for dilution of mine drainage and other wastes in the basin. Low sediment yields of supplying drainage areas would ensure a long life expectancy of reservoirs at these sites. Overbank flooding of the main stem of the Swatara Creek and its tributaries has occurred many times in the past. However, it has not been a hazard because urban development has not encroached on the flood plain. An inundation map of the August 1933 flood provides a basis that urban planners may use to avoid future damage. As water in the Swatara Creek moves downstream to the Susquehanna River, the flow is influenced consecutively by a large annual rainfall on the northern valley and ridge area, the wastes of surface and subsurface coal-mining activities, and less annual rainfall on the part of the basin lying in the Lebanon Plateau area; the flow is supplemented and further influenced by many tributaries and by the industrial and domestic wastes that are carried by these secondary streams. The annual precipitation ranges from 52 inches at the east edge and 49 inches at the west edge of the mountainous part of the basin to about 41 inches at the southwestern part at Middletown. The rainfall generally is adequate during the growing season to mature the crops. The mean annual temperature at Lebanon is about 52°F, and the growing season is about 180 days. In this report the basin has been divided into eight hydrologic zones, leased on runoff, natural use of water, and chemical character of water. Four zones lie in the valley and ridge area, three lie in the Lebanon Plateau area, and one lies in the highland along the southeastern basin boundary. In each of the zones the hydrologic characteristics are virtually the same, but they may be completely different from those in adjacent zones. The boundaries of the zones generally coincide with boundaries between geologic formations, and the areas in each zone include rocks of similar influence on water. Streams in zone 4 at the northeast edge of the plateau have the highest average surface runoff from 1.2 to 1.1 mgd per sq mi whereas those in zone 2 at the northwest edge of the valley and ridge area have the lowest, about 1.0 mgd. Streams in zone 8, along the southeast edge of the basin, have the largest sustained low-flow yield, about 0.26 to 0.19 mgd per sq mi; those in zone 5 overlying the Martinsburg Shale east of Harrisburg have the smallest sustained low-flow yields, 0.03 to 0.01 mgd. Streams in the limestone area of zone 7 have the greatest range in low-flow yields in any one zone from 0.60 to 0 mgd per sq mi. Low-flow yields in zones 1 through 4 range from 0.13 to 0.03 mgd per sq mi. Surface flows from zones 1 and 2 are generally acidic and contain high concentrations of sulfate, iron, and total dissolved solids especially where contaminated with mine wastes. Surface flows from zones 3 and 4 are dilute, slightly alkaline, and suitable for public water supplies. Surface flows from zones 5, 6, and 7 are alkaline and contain moderate concentrations of dissolved solids with waters of highest hardness occurring in zone 7. Surface flows from zone 8 are dilute to moderately mineralized and are relatively high in silica concentration. Nitrate concentrations are high in surf Fee flows below sewage outfalls and in ground water contaminated by septic tank effluent and industrial wastes. Average annual sediment yields of 550 to 650 tons per square mile are characteristic of zones 1 and 2 where strip mining has destroyed the forest cover and coal culm is carried into the streams. From agricultural lands on the Martinsburg Shale in zones 5 and 6, annual sediment yields range from 300 to 350 tons per square mile; but from agricultural lands on the siliceous rocks in zone 8 and zones 3 and 4 in the valley and ridge area, the sediment yield ranges from 200 to 250 tons annually per square mile. Lowest annual sediment yields in the basin are in the forested areas of siliceous rocks in zones 2, 3, 4, and 5, and in the sinkhole topography of the limestones in zone 7 where the yield ranges from 30 to 35 tons and 50 to 60 tons per square mile, respectively. The amount of ground water that can be developed in the basin is dependent on the ability of the underlying rocks to yield water to wells. More than 300 gpm (gallons per minute) can be obtained from wells in alluvial materials in the valley bottoms and in some of the limestones where large solution channels and fractures are penetrated by the wells. From 50 to 300 gpm can be obtained from wells in loosely cemented sandstones and in fractured limestones. From 10 to 50 gpm can be developed from wells in the shales and harder sandstones. The most dense rocks will yield from 1 to 10 gpm from fractures and crevices. Most wells yield water from the upper 350 feet of the formation, for this part contains the most fractures or solution channels. Studies show that the velocity at which a contaminant will move downstream in the basin is related to the discharge of the stream at the time. At a stream discharge of about 400 mgd at Pine Grove, a contaminant in Swatara Creek would require about 40 hours to move from Pine Grove to Middletown. As a result of dispersion and dilution, the maximum concentration of the contaminant at Middletown would be less than 20 percent the concentration at Pine Grove under these conditions. An evaluation of the availability of water in the basin indicates that about I,239 mgd enters as precipitation, 630 mgd leaves as streamflow, 580 mgd is evaporated and transpired, and 56 mgd is diverted for use by man. Not all the diversions for man's use are lost to the basin, as about 27 mgd is returned as sewage for reuse. About one-fourth of the waste water is returned to the ground and the remainder to stream drainageways. Of that diverted by man, 11.6 mgd is used for public supply and 44.4 mgd for industrial and private supplies. Diversions of streamflow furnish 86 percent of the public supply and 27 percent of the industrial supply, and ground-water sources yield the remainder. Municipal and private sewage treatment plants are upgrading the waste water in many places, but no provisions are being made for treatment other than natural dilution and assimilation for the 15 mgd of coal-nine drainage in the northern part of the basin. Technology for economic treatment of mine water is not available at this time, although research in this field is being done. Urbanization eastward from Harrisburg and around Lebanon has increased the population density of the basin. Densities of 500 people per square mile and water use exceeding 2.0 mgd per sq mi can be expected in the future. By the year 2000 the population of the basin may increase 60 percent; and if the per capita rate of use increases 0.5 percent per year the domestic requirements for water will be about two times the present use, or 23 mgd. Similarly, if the present 1:4 ratio of domestic use to industrial use of water continues, at least 89 mgd will be needed for industry in the future. Although an increase to twice the present use of water can be foreseen, or 112 mgd, water for the dilution and assimilation of wastes from treatment systems are not included. Providing water for dilution of wastes from treatment plants has not been a problem, but in the future the amounts needed for this purpose will be greater as the population increases. As water becomes more valuable, treatment of sewage wastes to reduce the biochemical-oxygen-demand load by at least 80 to 90 percent will be necessary to conserve water for more productive uses. As much as 100 mgd may be needed for waste dilution in the basin by year 2000. The present trends in suburban and light industrial development will probably persist in the basin. Problems arising through changes in economic value of water, conflicts in use, and alternatives in development are typical of those confronting the manager of a water-resource system.

Pennsylvania↗
USGS2010

Measurement and computation of bed-material discharge in a shallow sand-bed stream, Muddy Creek, Wyoming

Both the measurement and computation of the bed-material discharge of a stream involve large uncertainties because of the difficulties in determining bedload discharge. Measurements of bedload discharge are rare and frequently of unknown accuracy because no bedload sampler has been extensively tested and calibrated over a wide range of hydraulic conditions. Bed-material discharge equations have been derived primarily from laboratory flume data where the effects of channel pattern, alluvial banks, sediment availability, sediment sorting, and unsteady flow upon the sediment discharge of a natural stream have not been simulated. Bed-material discharge equations generally are applicable only within the range of flow conditions and sediment sizes for which the equations were derived. To compare the relative value of measuring versus computing bed-material discharges, the bed-material discharge of Muddy Creek, a shallow sand-bed stream in southwestern Wyoming, was determined on 35 occasions for water discharges ranging from 0.15 to 1.57 m 3 /s by separately sampling the suspended- and bedload-sediment discharges. Measured bed-material discharges were statistically indistinguishable, at an 0.02 level of significance, from flume data collected under the same flow conditions. This agreement indicates that the measured bed-material discharges are reasonable estimates of the true values. Bed-material discharges computed by Engelund-Hansen, Yang, Shen-Hung, and Ackers-White equations were compared with the measured values and found to be in good agreement. These equations predicted bed-material discharges of between 0.5 to 2 times the observed rates 60% to 79% of the time.

Wyoming↗
USGS1999

Improved method for the determination of nonpurgeable suspended organic carbon in natural water by silver filter filtration, wet chemical oxidation, and infrared spectrometry

Precision and accuracy are reported for the first time for the analysis of nonpurgeable suspended organic carbon by silver membrane filtration followed by wet chemical oxidation. A water sample is pressure filtered through a 0.45‐μm‐pore‐size, 47‐mm‐diameter silver membrane filter. The silver membrane filter then is cut into ribbons and placed in a flame‐sealable glass ampule. The organic material trapped on the membrane filter strips is acidified, purged with oxygen to remove inorganic carbonates and volatile organic compounds, and oxidized to carbon dioxide (CO 2 ) using phosphoric acid and potassium persulfate in the sealed glass ampule. The resulting CO 2 is measured by a nondispersive infrared CO 2 detector. The amount of CO 2 is proportional to the concentration of chemically oxidizable nonpurgeable organic carbon in the environmental water sample. The quantitation and method detection limit for routine analysis is 0.2 mg/L. The average percent recovery in five representative matrices was 97 ± 11%. The errors associated with sampling and sample preparation of nonpurgeable suspended organic carbon are also described.

Water Resources Research↗
USGS2009

Composition of the seed bank in drawdown areas of navigation pool 8 of the upper Mississippi river

In an effort to enhance aquatic plant production and habitat diversity on the Upper Mississippi River (UMR), resource managers considered water level reduction as a management tool to increase the area of emergent and submersed aquatic vegetation by natural seed germination. To quantify the availability of seed, we assessed the potential seed bank of selected areas of Navigation Pool 8 of the UMR from substrate samples collected in spring 2000. We tested these samples for viable seed content under four hydrologic conditions: dry, moist, shallow flooded and submerged. Forty-seven species were identified in the seed bank, including 27 obligate wetland, 10 facultative wetland and 7 upland species. Dominant taxa within the seed bank included Sagittaria spp., Lindernia dubia, Zosterella dubia, Cyperus spp., Eragrostis spp. and Leersia oryzoides. Of the four hydrologic treatments, moist substrates had the greatest species diversity and were the most productive, yielding an average density of 1420 seedlings m -2 . Emergent and submersed aquatic species were widely distributed, each type occurring in more than 90% of the samples. Timing of seedling germination varied among species and has implications for scheduling drawdowns to promote establishment of desired species. Seed bank results were correlated with the vegetation response on substrates exposed during a reduction of water levels of Pool 8 during summer 2001. Experimentally determining the composition and viability of seed banks from drawdown areas provides information useful in predicting the types of vegetation that may develop on exposed substrates. Further, these findings provide resource managers a better understanding of the potential for achieving desired vegetation response through water level reductions.

River Research and Applications↗
USGS2018

A multiscale investigation of habitat use and within-river distribution of sympatric sand darter species

The western sand darter Ammocrypta clara, and eastern sand darter Ammocrypta pellucida, are sand-dwelling fishes of conservation concern. Past research has emphasized the importance of studying individual populations of conservation concern, while recent research has revealed the importance of incorporating landscape scale processes that structure habitat mosaics and local populations. We examined habitat use and distributions of western and eastern sand darters in the lower Elk River of West Virginia. At the sandbar habitat use scale, western sand darters were detected in sandbars with greater area, higher proportions of coarse grain sand and faster bottom current velocity, while the eastern sand darter used a wider range of sandbar habitats. The landscape scale analysis revealed that contributing drainage area was an important predictor for both species, while sinuosity, which presumably represents valley type, also contributed to the western sand darter’s habitat suitability. Sandbar quality (area, grain size, and velocity) and fluvial geomorphic variables (drainage area and valley type) are likely key driving factors structuring sand darter distributions in the Elk River. This multiscale study of within-river species distribution and habitat use is unique, given that only a few sympatric populations are known of western and eastern sand darters.

West Virginia↗
USGS2000

Unsaturated‐zone wedge beneath a large, natural lake

Lake Belle Taine (480 ha) in north central Minnesota receives on average 76,000 m 3 d −1 of water from Little Sand Creek but has no outlet. Water seeps out of the lake, flows through glacial outwash, and discharges into three nearby lakes with stages 13–14 m lower than Belle Taine. Seepage‐meter data indicate water is seeping out of Belle Taine at velocities up to 263 cm d −1 . Hydraulic‐head measurements made in the lake bed indicate the sediments are unsaturated beneath a portion of the lake edge, and a wedge of unsaturated sediments extends beneath the lake bed as much as 20 m from the shoreline. At the shoreline the water table is as much as 6.7 m below the lake surface. Modeling results of a similar hypothetical setting indicate that the horizontal extent of an unsaturated zone beneath a lake depends on (1) the permeability contrast between the outwash and the lake bed, (2) anisotropy, (3) lake bed slope, and (4) thickness of the lower‐permeability lake bed sediments. Although rarely documented, unsaturated sediments beneath a lake may not be extremely uncommon. Similar, much smaller unsaturated‐zone areas also have been observed beneath two other lakes in Minnesota.

Minnesota↗
USGS2024

Reproduction of grass carp (Ctenopharyngodon idella) in the Maumee River, Ohio: Part 1—Spawning area identification using bidirectional drift modeling

Control of invasive grass carp ( Ctenopharyngodon idella ) populations in the Western Lake Erie Basin merits adaptive management guided by the best available science. Presently (2024), capture of mature grass carp in rivers during spawning season is most efficient, so knowing when and where grass carp are spawning is essential information for natural resource agencies. Using bidirectional drift modeling and grass carp ichthyoplankton samples captured in the Maumee River during the 2017–2019 spawning seasons, this study identified 12 probable grass carp spawning areas in the lower 96.5-kilometers of the Maumee River. These spawning areas were located both above and below the Grand Rapids/Providence low-head dams. Three areas showed evidence of multiyear use, while nine had multi-event use. Spawning activity had no definitive diel variation and occurred at an average photoperiod of 15.15 h. The maturation metric ADD15, or annual degree days above 15 degrees Celsius, generally exceeded the 655 threshold for spawning; however, some spawning occurred when ADD15 ≤235, indicating spawners likely matured in a warmwater discharge. The probable spawning areas were generally characterized by mean velocities between 0.4 and 2.1 m per second (with locally higher velocities possible), areas of high turbulence produced by dam spillways or bedrock outcroppings, channel constrictions, confluences, islands, and bridges with piers in the water. Spawning suitability indices (SSI), based on velocity, varied considerably between spawning areas and SSI models. These results could be used to inform control efforts and predict potential grass carp spawning locations in other rivers under threat of invasion.

Ohio↗
USGS2008

Large-scale natural gradient tracer test in sand and gravel, Cape Cod, Massachusetts: 1. Experimental design and observed tracer movement

A large-scale natural gradient tracer experiment was conducted on Cape Cod, Massachusetts, to examine the transport and dispersion of solutes in a sand and gravel aquifer. The nonreactive tracer, bromide, and the reactive tracers, lithium and molybdate, were injected as a pulse in July 1985 and monitored in three dimensions as they moved as far as 280 m down-gradient through an array of multilevel samplers. The bromide cloud moved horizontally at a rate of 0.42 m per day. It also moved downward about 4 m because of density-induced sinking early in the test and accretion of areal recharge from precipitation. After 200 m of transport, the bromide cloud had spread more than 80 m in the direction of flow, but was only 14 m wide and 4–6 m thick. The lithium and molybdate clouds followed the same path as the bromide cloud, but their rates of movement were retarded about 50% relative to bromide movement because of sorption onto the sediments.

Massachusetts↗
USGS2007

Global impacts of conversions from natural to agricultural ecosystems on water resources: Quantity versus quality

Past land use changes have greatly impacted global water resources, with often opposing effects on water quantity and quality. Increases in rain‐fed cropland (460%) and pastureland (560%) during the past 300 years from forest and grasslands decreased evapotranspiration and increased recharge (two orders of magnitude) and streamflow (one order of magnitude). However, increased water quantity degraded water quality by mobilization of salts, salinization caused by shallow water tables, and fertilizer leaching into underlying aquifers that discharge to streams. Since the 1950s, irrigated agriculture has expanded globally by 174%, accounting for ∼90% of global freshwater consumption. Irrigation based on surface water reduced streamflow and raised water tables resulting in waterlogging in many areas (China, India, and United States). Marked increases in groundwater‐fed irrigation in the last few decades in these areas has lowered water tables (≤1 m/yr) and reduced streamflow. Degradation of water quality in irrigated areas has resulted from processes similar to those in rain‐fed agriculture: salt mobilization, salinization in waterlogged areas, and fertilizer leaching. Strategies for remediating water resource problems related to agriculture often have opposing effects on water quantity and quality. Long time lags (decades to centuries) between land use changes and system response (e.g., recharge, streamflow, and water quality), particularly in semiarid regions, mean that the full impact of land use changes has not been realized in many areas and remediation to reverse impacts will also take a long time. Future land use changes should consider potential impacts on water resources, particularly trade‐offs between water, salt, and nutrient balances, to develop sustainable water resources to meet human and ecosystem needs.

Water Resources Research↗
USGS2010

Biosecurity Plan for Palmyra Atoll

This Biosecurity Plan for Palmyra Atoll was developed for The Nature Conservancy (TNC) Palmyra Program to refine and expand goals and objectives developed through the Conservation Action Plan process. The Biosecurity Plan is one in a series of adaptive management plans designed to achieve TNC's mission toward the protection and enhancement of native wildlife and habitat. The Biosecurity Plan focuses on ecosystem security, and specifically identifies and addresses issues related to non-native and potentially invasive species. The Plan attempts to identify pathways of invasion and strategies for preventing or reducing new introductions. Overall, the Biosecurity Plan provides a framework to implement and track the progress of conservation and restoration goals related to non-native species on Palmyra Atoll. Palmyra Atoll is one of the Northern Line Islands in the Pacific Ocean southwest of the Hawai`ian Islands. It consists of many heavily vegetated islets arranged in a horseshoe pattern around four lagoons and surrounded by a coral reef. At present, Palmyra Atoll harbors various non-native or invasive species in the terrestrial and marine ecosystems. The most notable examples of terrestrial invasive species include coconut trees (Cocos nucifera) and black rats (Rattus rattus). Although it is unclear whether they are non-native, coconut trees are currently the most dominant plant across Palmyra Atoll. They compete with native plant species for space and resources, and are potentially detrimental to seabirds dependent on native vegetation. Black rats are known to predate ground-nesting seabirds and are likely responsible for the lack of burrowing seabird reproduction on Palmyra Atoll. The most notable example of a marine invasive species is the corallimorph (Rhodactis howsei). Although Rhodactis howsei is a native species, it can take advantage of human-altered habitat and significantly change the natural habitat by aggressively outcompeting native corals. Although the extent and impacts of these and other non-native and (or) invasive species are not fully understood, they are clearly a threat to the native species and overall ecosystem integrity of Palmyra Atoll. In fact, non-native invasive species have been considered the most important threat to ecosystems in Hawai`i and the second most important threat to biodiversity world-wide. Palmyra Atoll is somewhat protected because of its remote location, but there are still potential pathways for the introduction of non-native and possibly invasive species. With the continued influx of aircraft and ocean vessels and their contents to and around Palmyra Atoll, we anticipate many more concerns related to the import and spread of non-native invasive species in the future. In terms of ecosystem security, prevention is the most effective and efficient tool for managing invasive species. There are various potential pathways for introduction and spread of non-native species within Palmyra Atoll's terrestrial and marine ecosystems. Identification of these pathways provides a first step in preventing introductions. We also recommend establishing, enhancing, and enforcing quarantine protocols to prevent future non-native species invasions. Other critical steps to minimize the impacts and spread of invasive species include early detection through inventory and monitoring, as well as containment, control, and management of non-native species already established at Palmyra Atoll. These efforts in combination with research and education will serve to inform management decisions related to ecosystem integrity. Along with reinstating ecosystem security, this Biosecurity Plan aims to evaluate new risk factors related to non-native and potentially invasive species. To that end, an adaptive management process of audit and review is highly recommended to ensure the implementation and efficacy of the management practices outlined above. In addition, it will be important to identify high r

Open-File Report↗
USGS2012

Maximizing the utility of monitoring to the adaptive management of natural resources

Data collection is an important step in any investigation about the structure or processes related to a natural system. In a purely scientific investigation (experiments, quasi-experiments, observational studies), data collection is part of the scientific method, preceded by the identification of hypotheses and the design of any manipulations of the system to test those hypotheses. Data collection and the manipulations that precede it are ideally designed to maximize the information that is derived from the study. That is, such investigations should be designed for maximum power to evaluate the relative validity of the hypotheses posed. When data collection is intended to inform the management of ecological systems, we call it monitoring. Note that our definition of monitoring encompasses a broader range of data-collection efforts than some alternative definitions – e.g. Chapter 3. The purpose of monitoring as we use the term can vary, from surveillance or “thumb on the pulse” monitoring (see Nichols and Williams 2006), intended to detect changes in a system due to any non-specified source (e.g. the North American Breeding Bird Survey), to very specific and targeted monitoring of the results of specific management actions (e.g. banding and aerial survey efforts related to North American waterfowl harvest management). Although a role of surveillance monitoring is to detect unanticipated changes in a system, the same result is possible from a collection of targeted monitoring programs distributed across the same spatial range (Box 4.1). In the face of limited budgets and many specific management questions, tying monitoring as closely as possible to management needs is warranted (Nichols and Williams 2006). Adaptive resource management (ARM; Walters 1986, Williams 1997, Kendall 2001, Moore and Conroy 2006, McCarthy and Possingham 2007, Conroy et al. 2008a) provides a context and specific purpose for monitoring: to evaluate decisions with respect to achievement of specific management objectives; and to evaluate the relative validity of predictive system models. This latter purpose is analogous to the role of data collection within the scientific method, in a research context.

Book chapter↗
USGS2020

Timescales and processes of methane hydrate formation and breakdown, with application to geologic systems

Gas hydrate is an ice-like form of water and low molecular weight gas stable at temperatures of roughly -10ºC to 25ºC and pressures of ~3 to 30 MPa in geologic systems. Natural gas hydrates sequester an estimated one-sixth of Earth’s methane and are found primarily in deepwater marine sediments on continental margins, but also in permafrost areas and under continental ice sheets. When gas hydrate is removed from its stability field, its breakdown has implications for the global carbon cycle, ocean chemistry, marine geohazards, and interactions between the geosphere and the ocean-atmosphere system. Gas hydrate breakdown can also be artificially driven as a component of studies assessing the resource potential of these deposits. Furthermore, geologic processes and perturbations to the ocean-atmosphere system (e.g., warming temperatures) can cause not only dissociation, but also more widespread dissolution of hydrate or even formation of new hydrate in reservoirs. Linkages between gas hydrate and disparate aspects of Earth’s near-surface physical, chemical, and biological systems render an assessment of the rates and processes affecting the persistence of gas hydrate an appropriate Centennial Grand Challenge. This paper reviews the thermodynamic controls on methane hydrate stability and then describes the relative importance of kinetic, mass transfer, and heat transfer processes in the formation and breakdown (dissociation and dissolution) of gas hydrate. Results from numerical modeling, laboratory, and some fields studies are used to summarize the rates of hydrate formation and breakdown, followed by an extensive treatment of hydrate dynamics in marine and cryospheric gas hydrate systems.

Journal of Geophysical Research-Solid Earth↗
USGS2014

A synoptic examination of causes of land loss in southern Louisiana as related to the exploitation of subsurface geologic resources

During the last 80 years, Louisiana has been losing wetlands at an average rate of 62 km 2 /y (24 mi 2 /y) for an accumulated loss of approximately 4900 km 2 (1900 mi 2 ). The loss seems to be the combined result of natural and anthropogenic causes that are behind primarily land subsidence averaging about 10 mm/y (0.4 in/y) coinciding with a sea level rise now at 3 mm/y (0.1 in/y), both contributing to coastal inundation. Upon completing extensive review of often controversial and conflicting views only synoptically reported here, conclusions reached by applying Monte Carlo simulation include: (1) geodetic measurements are consistent with independently postulated causes of regional subsidence; (2) ranking of subsidence factors shows that the main contributor to the regional subsidence is adjustment to sediment load in the form of lithosphere flexure followed by normal faulting dipping basinward, which combined, account on average for 70% of the subsidence, with compaction accounting for another 23%; and (3) production of oil and gas plays a tertiary role. The literature supports the historical view that before experiencing engineering modifications across the catchment area, sedimentation from the Mississippi River system was able to build a prograding coastline by overcoming subsidence rates of similar magnitude with more generous sediment loads of coarser particle size. Sea level rise will become an increasingly dominant factor in land loss only if the acceleration predicted by simulation model scenarios materializes. Wetland losses most likely will continue for as long as there is no compensation to counterbalance the negative effects of land subsidence and sea level rise, with the latter determining the pace of future losses.

Louisiana↗
USGS2010

Modeling biotic uptake by periphyton and transient hyporrheic storage of nitrate in a natural stream

To a convection-dispersion hydrologic transport model we coupled a transient storage submodel (Bencala, 1984) and a biotic uptake submodel based on Michaelis-Menten kinetics (Kim et al., 1990). Our purpose was threefold: (1) to simulate nitrate retention in response to change in load in a third-order stream, (2) to differentiate biotic versus hydrologie factors in nitrate retention, and (3) to produce a research tool whose properties are consistent with laboratory and field observations. Hydrodynamic parameters were fitted from chloride concentration during a 20-day chloride-nitrate coinjection (Bencala, 1984), and biotic uptake kinetics were based on flume studies by Kim et al. (1990) and Triska et al. (1983). Nitrate concentration from the 20-day coinjection experiment served as a base for model validation. The complete transport retention model reasonably predicted the observed nitrate concentration. However, simulations which lacked either the transient storage submodel or the biotic uptake submodel poorly predicted the observed nitrate concentration. Model simulations indicated that transient storage in channel and hyporrheic interstices dominated nitrate retention within the first 24 hours, whereas biotic uptake dominated thereafter. A sawtooth function for V max ranging from 0.10 to 0.17 μg NO 3 -N s −1 gAFDM −1 (grams ash free dry mass) slightly underpredicted nitrate retention in simulations of 2–7 days. This result was reasonable since uptake by other nitrate-demanding processes were not included. The model demonstrated how ecosystem retention is an interaction between physical and biotic processes and supports the validity of coupling separate hydrodynamic and reactive submodels to established solute transport models in biological studies of fluvial ecosystems.

California↗
USGS2002

Evaluation of potential impacts on Great Lakes water resources based on climate scenarios of two GCMs

The results of general circulation model predictions of the effects of climate change from the Canadian Centre for Climate Modeling and Analysis (model CGCM1) and the United Kingdom Meteorological Office's Hadley Centre (model HadCM2) have been used to derive potential impacts on the water resources of the Great Lakes basin. These impacts can influence the levels of the Great Lakes and the volumes of channel flow among them, thus affecting their value for interests such as riparians, shippers, recreational boaters, and natural ecosystems. On one hand, a hydrological modeling suite using input data from the CGCM1 predicts large drops in lake levels, up to a maximum of 1.38 m on Lakes Michigan and Huron by 2090. This is due to a combination of a decrease in precipitation and an increase in air temperature that leads to an increase in evaporation. On the other hand, using input from HadCM2, rises in lake levels are predicted, up to a maximum of 0.35 m on Lakes Michigan and Huron by 2090, due to increased precipitation and a reduced increase in air temperature. An interest satisfaction model shows sharp decreases in the satisfaction of the interests of commercial navigation, recreational boating, riparians, and hydropower due to lake level decreases. Most interest satisfaction scores are also reduced by lake level increases. Drastic reductions in ice cover also result from the temperature increases such that under the CGCM1 predictions, most of Lake Erie has 96% of its winters ice-free by 2090. Assessment is also made of impacts on the groundwater-dependent region of Lansing, Michigan.

Great Lakes basin↗
USGS2014

An evaluation of the relations between flow regime components, stream characteristics, species traits and meta-demographic rates of warmwater stream fishes: Implications for aquatic resource management

Fishery biologists are increasingly recognizing the importance of considering the dynamic nature of streams when developing streamflow policies. Such approaches require information on how flow regimes influence the physical environment and how those factors, in turn, affect species-specific demographic rates. A more cost-effective alternative could be the use of dynamic occupancy models to predict how species are likely to respond to changes in flow. To appraise the efficacy of this approach, we evaluated relative support for hypothesized effects of seasonal streamflow components, stream channel characteristics, and fish species traits on local extinction, colonization, and recruitment (meta-demographic rates) of stream fishes. We used 4 years of seasonal fish collection data from 23 streams to fit multistate, multiseason occupancy models for 42 fish species in the lower Flint River Basin, Georgia. Modelling results suggested that meta-demographic rates were influenced by streamflows, particularly short-term (10-day) flows. Flow effects on meta-demographic rates also varied with stream size, channel morphology, and fish species traits. Small-bodied species with generalized life-history characteristics were more resilient to flow variability than large-bodied species with specialized life-history characteristics. Using this approach, we simplified the modelling framework, thereby facilitating the development of dynamic, spatially explicit evaluations of the ecological consequences of water resource development activities over broad geographic areas. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

Georgia↗
USGS2019

Cooperative Fish and Wildlife Research Units program—2018 year in review

The Cooperative Fish and Wildlife Research Units (CRU) program had an interesting and challenging year in 2018. We made significant strategic advances on many fronts and had setbacks in others. Our relationship with the U.S. Fish and Wildlife Service, the agency we belonged to from 1935 to the mid-1990s, was further reinforced through strategic efforts with the Service’s Science Applications senior staff. This is bearing fruit in terms of research collaborations and funding support. As part of a larger effort between the U.S. Geological Survey (USGS) Ecosystems Mission Area and the Service’s endangered species program, we are also collaborating to address science needs for species in pre-listing status. Barry Grand, Unit Supervisor (South), has been instrumental in this effort. Tom Edwards of the Utah Unit has met with representatives of the U.S. Fish and Wildlife Service and the Association of Fish and Wildlife Agencies to promote training of leaders and “hands dirty” biologists in species distribution modeling. The Association passed a unanimous resolution endorsing the training at their midyear meeting in March. Tom held a workshop at the annual meeting of the Association of Fish and Wildlife Agencies in September, and future workshops, supported by the U.S. Fish and Wildlife Service, will be held bringing State agency and U.S. Fish and Wildlife Service biologists together to work on species of common concern. Wyoming Unit Leader Matt Kauffman’s pioneering work in identifying and mapping big-game migration corridors has captured the attention of conservationists far and wide. In the spring, the Secretary of the Interior signed Secretarial Order No. 3362, "Improving Habitat Quality in Western Big-Game Winter Range and Migration Corridors" directing efforts of several U.S. Department of the Interior (DOI) bureaus to collaborate with States in identifying and protecting big-game corridors in 11 States. Matt has conducted several workshops that directly support the Secretarial order, and more are planned. Corridor mapping efforts supported by the USGS and the DOI, based in the States and coordinated by Matt, are unfolding. Unit Administrative Officer Shana Coulby and her staff hosted a training program for university support staff at USGS National Headquarters in March. Shana’s team did a superb job, and the camaraderie among all was evident. We co-sponsored the third in a series of workshops at the North American Wildlife and Natural Resources Conference in March on bridging the gap between science and management. The State Department requested that we coordinate a workshop that would bring CRU scientists and other U.S. representatives together with Brazilian, Colombian, and Peruvian scientists and decision makers to develop best practices to minimize environmental damage from infrastructure development in the Amazon and to collaborate on science needs. The workshop was held in Iquitos, Peru, in the heart of the Amazon during August. Our cooperator community, represented by the National Cooperators Coalition, was very active in response to the President’s budget proposal that would have redirected funding for the CRU program to other priorities. Their efforts are reflected in the House and Senate marks on the fiscal year 2019 budget that not only restored funding, but recommended increases. You will see in this report many other accomplishments of our individual scientists and students during 2018. It was an impressive and productive year! What you won’t see chronicled is the work of the CRU headquarters staff and University support staff. These folks are extraordinary in their dedication to working with cooperators and scientists to solve problems and ensure the important work gets accomplished with minimal interference. We are truly fortunate to have such skilled and dedicated folks in the trenches. I was fortunate to visit several units during 2018. For me, this is the most enriching part of my duties. I get to see firsthand the work our scientists do, the incredible students being mentored, and meet our cooperators on their turf. As we look forward towards the horizon, 2019 looks brighter for the CRU program. Efforts by our cooperators to generate support for filling our vacancies are materializing. Our cadre of scientists is second to none, and the breadth and depth of our work are nothing short of impressive. Thanks to all who are part of this cooperative endeavor—conservation is the ultimate winner in our efforts!

Circular↗