In extreme environments, retention of nutrients within stream ecosystems contributes to the persistence of aquatic biota and continuity of ecosystem function. In the McMurdo Dry Valleys, Antarctica, many glacial meltwater streams flow for only 5–12 weeks a year and yet support extensive benthic microbial communities. We investigated NO3− uptake and denitrification in Green Creek by analyzing small‐scale microbial mat dynamics in mesocosms and reach‐scale nutrient cycling in two whole‐stream NO3− enrichment experiments. Nitrate uptake results indicated that microbial mats were nitrogen (N)‐limited, with NO3− uptake rates as high as 16 nmol N cm−2 h−1. Denitrification potentials associated with microbial mats were also as high as 16 nmol N cm−2 h−1. During two whole‐stream NO3−−enrichment experiments, a simultaneous pulse of NO2− was observed in the stream water. The one‐dimensional solute transport model with inflow and storage was modified to simulate two storage zones: one to account for short time scale hydrologic exchange of stream water into and out of the benthic microbial mat, the other to account for longer time scale hydrologic exchange with the hyporheic zone. Simulations indicate that injected NO3− was removed both in the microbial mat and in the hyporheic zone and that as much as 20% of the NO3− that entered the microbial mat and hyporheic zone was transformed to NO2− by dissimilatory reduction. Because of the rapid hydrologic exchange in microbial mats, it is likely that denitrification is limited either by biotic assimilation, reductase limitation, or transport limitation (reduced NO2− is transported away from reducing microbes).
Theory is derived from the work of Urey (Urey H. C. [1947] The thermodynamic properties of isotopic substances. J. Chem. Soc. 562–581) to calculate equilibrium constants commonly used in geochemical equilibrium and reaction-transport models for reactions of individual isotopic species. Urey showed that equilibrium constants of isotope exchange reactions for molecules that contain two or more atoms of the same element in equivalent positions are related to isotope fractionation factors by α = (Kex)1/n, where n is the number of atoms exchanged. This relation is extended to include species containing multiple isotopes, for example 13C16O18O and 1H2H18O. The equilibrium constants of the isotope exchange reactions can be expressed as ratios of individual isotope equilibrium constants for geochemical reactions. Knowledge of the equilibrium constant for the dominant isotopic species can then be used to calculate the individual isotope equilibrium constants.
Individual isotope equilibrium constants are calculated for the reaction CO2g = CO2aq for all species that can be formed from 12C, 13C, 16O, and 18O; for the reaction between 12C18O2aqand 1H218Ol; and among the various 1H, 2H, 16O, and 18O species of H2O. This is a subset of a larger number of equilibrium constants calculated elsewhere (Thorstenson D. C. and Parkhurst D. L. [2002] Calculation of individual isotope equilibrium constants for implementation in geochemical models. Water-Resources Investigation Report 02-4172. U.S. Geological Survey). Activity coefficients, activity-concentration conventions for the isotopic variants of H2O in the solvent 1H216Ol, and salt effects on isotope fractionation have been included in the derivations. The effects of nonideality are small because of the chemical similarity of different isotopic species of the same molecule or ion. The temperature dependence of the individual isotope equilibrium constants can be calculated from the temperature dependence of the fractionation factors.
The derivations can be extended to calculation of individual isotope equilibrium constants for ion pairs and equilibrium constants for isotopic species of other chemical elements. The individual isotope approach calculates the same phase isotopic compositions as existing methods, but also provides concentrations of individual species, which are needed in calculations of mass-dependent effects in transport processes. The equilibrium constants derived in this paper are used to calculate the example of gas-water equilibrium for CO2 in an acidic aqueous solution.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.gca.2003.11.027","issn":"00167037","usgsCitation":"Thorstenson, D., and Parkhurst, D., 2004, Calculation of individual isotope equilibrium constants for geochemical reactions: Geochimica et Cosmochimica Acta, v. 68, no. 11, p. 2449-2465, https://doi.org/10.1016/j.gca.2003.11.027.","productDescription":"17 p.","startPage":"2449","endPage":"2465","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":234137,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":208406,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.gca.2003.11.027"}],"volume":"68","issue":"11","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f303e4b0c8380cd4b552","contributors":{"authors":[{"text":"Thorstenson, D.C.","contributorId":47377,"corporation":false,"usgs":true,"family":"Thorstenson","given":"D.C.","email":"","affiliations":[],"preferred":false,"id":410183,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Parkhurst, D.L.","contributorId":12474,"corporation":false,"usgs":true,"family":"Parkhurst","given":"D.L.","email":"","affiliations":[],"preferred":false,"id":410182,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70035346,"text":"70035346 - 2004 - Hydrology, metals, and aquatic physical habitat in the Upper Animas watershed, Colorado","interactions":[],"lastModifiedDate":"2012-03-12T17:21:54","indexId":"70035346","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Hydrology, metals, and aquatic physical habitat in the Upper Animas watershed, Colorado","docAbstract":"The Upper Animas River watershed in southwestern Colorado is a watershed with historic mining districts with many small mines and mills and a few larger mines and mills. The numbers of trout may be limited by high flows during the spring runoff period and by winter streamflows. In some locations there are large particles on the stream surface that may provide cover to trout. but the presence of fines in the substrate in some areas and the presence of large particles on the surface probably limits use of the subsurface by fish. During some parts of the year metals in the interstecial waters are toxic to many aquatic animas when the stream waters are much less toxic. The concentration of copper and zinc appear to be constant during streamflows that cause the bed material would be moved by the high discharges. Copyright 2004 ASCE.","largerWorkTitle":"Watershed Management and Operations Management 2000","conferenceTitle":"Watershed Management and Operations Management 2000","conferenceDate":"20 June 2000 through 24 June 2000","conferenceLocation":"Fort Collins, CO","language":"English","doi":"10.1061/40499(2000)5","isbn":"0784404992; 9780784404997","usgsCitation":"Milhous, R., 2004, Hydrology, metals, and aquatic physical habitat in the Upper Animas watershed, Colorado, in Watershed Management and Operations Management 2000, v. 105, Fort Collins, CO, 20 June 2000 through 24 June 2000, https://doi.org/10.1061/40499(2000)5.","costCenters":[],"links":[{"id":215403,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1061/40499(2000)5"},{"id":243205,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"105","noUsgsAuthors":false,"publicationDate":"2012-04-26","publicationStatus":"PW","scienceBaseUri":"505a377ce4b0c8380cd60f02","contributors":{"authors":[{"text":"Milhous, R.T.","contributorId":106845,"corporation":false,"usgs":true,"family":"Milhous","given":"R.T.","email":"","affiliations":[],"preferred":false,"id":450284,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70026609,"text":"70026609 - 2004 - Ground water chlorinated ethenes in tree trunks: Case studies, influence of recharge, and potential degradation mechanism","interactions":[],"lastModifiedDate":"2021-08-26T16:58:20.710865","indexId":"70026609","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1864,"text":"Ground Water Monitoring and Remediation","active":true,"publicationSubtype":{"id":10}},"title":"Ground water chlorinated ethenes in tree trunks: Case studies, influence of recharge, and potential degradation mechanism","docAbstract":"Trichloroethene (TCE) was detected in cores of trees growing above TCE-contaminated ground at three sites: the Carswell Golf Course in Texas, Air Force Plant PJKS in Colorado, and Naval Weapons Station Charleston in South Carolina. This was true even when the depth to water was 7.9 m or when the contaminated aquifer was confined beneath ∼3 m of clay. Additional ground water contaminants detected in the tree cores were cis-1,2-dichloroethene at two sites and tetrachloroethene at one site. Thus, tree coring can be a rapid and effective means of locating shallow subsurface chlorinated ethenes and possibly identifying zones of active TCE dechlorination. Tree cores collected over time were useful in identifying the onset of ground water contamination. Several factors affecting chlorinated ethene concentrations in tree cores were identified in this investigation. The factors include ground water chlorinated ethene concentrations and depth to ground water contamination. In addition, differing TCE concentrations around the trunk of some trees appear to be related to the roots deriving water from differing areas. Opportunistic uptake of infiltrating rainfall can dilute prerain TCE concentrations in the trunk. TCE concentrations in core headspace may differ among some tree species. In some trees, infestation of bacteria in decaying heartwood may provide a TCE dechlorination mechanism within the trunk.
","language":"English","publisher":"Wiley","doi":"10.1111/j.1745-6592.2004.tb01299.x","usgsCitation":"Vroblesky, D., Clinton, B., Vose, J., Casey, C., Harvey, G.J., and Bradley, P., 2004, Ground water chlorinated ethenes in tree trunks: Case studies, influence of recharge, and potential degradation mechanism: Ground Water Monitoring and Remediation, v. 24, no. 3, p. 124-138, https://doi.org/10.1111/j.1745-6592.2004.tb01299.x.","productDescription":"15 p.","startPage":"124","endPage":"138","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":234136,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"24","issue":"3","noUsgsAuthors":false,"publicationDate":"2010-08-24","publicationStatus":"PW","scienceBaseUri":"505a2aaae4b0c8380cd5b377","contributors":{"authors":[{"text":"Vroblesky, D.A.","contributorId":101691,"corporation":false,"usgs":true,"family":"Vroblesky","given":"D.A.","affiliations":[],"preferred":false,"id":410181,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Clinton, B.D.","contributorId":10204,"corporation":false,"usgs":true,"family":"Clinton","given":"B.D.","email":"","affiliations":[],"preferred":false,"id":410176,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Vose, J.M.","contributorId":22539,"corporation":false,"usgs":true,"family":"Vose","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":410178,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Casey, C.C.","contributorId":10206,"corporation":false,"usgs":true,"family":"Casey","given":"C.C.","email":"","affiliations":[],"preferred":false,"id":410177,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Harvey, G. J.","contributorId":72984,"corporation":false,"usgs":true,"family":"Harvey","given":"G.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":410180,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Bradley, P. M. 0000-0001-7522-8606","orcid":"https://orcid.org/0000-0001-7522-8606","contributorId":29465,"corporation":false,"usgs":true,"family":"Bradley","given":"P. M.","affiliations":[],"preferred":false,"id":410179,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70026595,"text":"70026595 - 2004 - Aquifer vulnerability to pesticide pollution: Combining soil, land-use and aquifer properties with molecular descriptors","interactions":[],"lastModifiedDate":"2018-11-14T08:51:49","indexId":"70026595","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2342,"text":"Journal of Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Aquifer vulnerability to pesticide pollution: Combining soil, land-use and aquifer properties with molecular descriptors","docAbstract":"This study uses an extensive survey of herbicides in groundwater across the midwest United States to predict occurrences of a range of compounds across the region from a combination of their molecular properties and the properties of the catchment of a borehole. The study covers 100 boreholes and eight pesticides. For each of the boreholes its catchment the soil, land-use and aquifer properties were characterized. Discriminating boreholes where pollution occurred from those where no pollution occurred gave a model that was 74% correct with organic carbon content, percentage sand content and depth to the water table being significant properties of the borehole catchment. Molecular topological descriptors as well as Koc, solubility and half-life were used to characterize each compound included in the study. Inclusion of molecular properties makes it possible to discriminate between occurrence and non-occurrence of each compound in each well. The best-fit model combines: organic carbon content, percentage sand content and depth to the water table with molecular descriptors representing molecular size, molecular branching and functional group composition of the herbicides.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.jhydrol.2004.01.013","issn":"00221694","usgsCitation":"Worrall, F., and Kolpin, D., 2004, Aquifer vulnerability to pesticide pollution: Combining soil, land-use and aquifer properties with molecular descriptors: Journal of Hydrology, v. 293, no. 1-4, p. 191-204, https://doi.org/10.1016/j.jhydrol.2004.01.013.","productDescription":"14 p.","startPage":"191","endPage":"204","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":351,"text":"Iowa Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":502536,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://durham-repository.worktribe.com/output/1576690","text":"External 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F.","contributorId":34687,"corporation":false,"usgs":true,"family":"Worrall","given":"F.","affiliations":[],"preferred":false,"id":410140,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kolpin, D.W.","contributorId":87565,"corporation":false,"usgs":true,"family":"Kolpin","given":"D.W.","email":"","affiliations":[],"preferred":false,"id":410141,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70035321,"text":"70035321 - 2004 - Simulating the effects of ground-water withdrawals on streamflow in a precipitation-runoff model","interactions":[],"lastModifiedDate":"2012-03-12T17:21:52","indexId":"70035321","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Simulating the effects of ground-water withdrawals on streamflow in a precipitation-runoff model","docAbstract":"Precipitation-runoff models are used to assess the effects of water use and management alternatives on streamflow. Often, ground-water withdrawals are a major water-use component that affect streamflow, but the ability of surface-water models to simulate ground-water withdrawals is limited. As part of a Hydrologic Simulation Program-FORTRAN (HSPF) precipitation-runoff model developed to analyze the effect of ground-water and surface-water withdrawals on streamflow in the Ipswich River in northeastern Massachusetts, an analytical technique (STRMDEPL) was developed for calculating the effects of pumped wells on streamflow. STRMDEPL is a FORTRAN program based on two analytical solutions that solve equations for ground-water flow to a well completed in a semi-infinite, homogeneous, and isotropic aquifer in direct hydraulic connection to a fully penetrating stream. One analytical method calculates unimpeded flow at the stream-aquifer boundary and the other method calculates the resistance to flow caused by semipervious streambed and streambank material. The principle of superposition is used with these analytical equations to calculate time-varying streamflow depletions due to daily pumping. The HSPF model can readily incorporate streamflow depletions caused by a well or surface-water withdrawal, or by multiple wells or surface-water withdrawals, or both, as a combined time-varying outflow demand from affected channel reaches. These demands are stored as a time series in the Watershed Data Management (WDM) file. This time-series data is read into the model as an external source used to specify flow from the first outflow gate in the reach where these withdrawals are located. Although the STRMDEPL program can be run independently of the HSPF model, an extension was developed to run this program within GenScn, a scenario generator and graphical user interface developed for use with the HSPF model. This extension requires that actual pumping rates for each well be stored in a unique WDM dataset identified by an attribute that associates each well with the model reach from which water is withdrawn. Other attributes identify the type and characteristics of the data. The interface allows users to easily add new pumping wells, delete exiting pumping wells, or change properties of the simulated aquifer or well. Development of this application enhanced the ability of the HSPF model to simulate complex water-use conditions in the Ipswich River Basin. The STRMDEPL program and the GenScn extension provide a valuable tool for water managers to evaluate the effects of pumped wells on streamflow and to test alternative water-use scenarios. Copyright ASCE 2004.","largerWorkTitle":"Bridging the Gap: Meeting the World's Water and Environmental Resources Challenges - Proceedings of the World Water and Environmental Resources Congress 2001","conferenceTitle":"World Water and Environmental Resources Congress 2001","conferenceDate":"20 May 2001 through 24 May 2001","conferenceLocation":"Orlando, FL","language":"English","doi":"10.1061/40569(2001)103","isbn":"0784405697; 9780784405697","usgsCitation":"Zarriello, P.J., Barlow, P.M., and Duda, P., 2004, Simulating the effects of ground-water withdrawals on streamflow in a precipitation-runoff model, in Bridging the Gap: Meeting the World's Water and Environmental Resources Challenges - Proceedings of the World Water and Environmental Resources Congress 2001, v. 111, Orlando, FL, 20 May 2001 through 24 May 2001, https://doi.org/10.1061/40569(2001)103.","costCenters":[],"links":[{"id":215550,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1061/40569(2001)103"},{"id":243362,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"111","noUsgsAuthors":false,"publicationDate":"2012-04-26","publicationStatus":"PW","scienceBaseUri":"505b8fd7e4b08c986b319184","contributors":{"authors":[{"text":"Zarriello, Philip J.","contributorId":21588,"corporation":false,"usgs":false,"family":"Zarriello","given":"Philip","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":450172,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Barlow, P. M.","contributorId":63022,"corporation":false,"usgs":true,"family":"Barlow","given":"P.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":450173,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Duda, P.B.","contributorId":8892,"corporation":false,"usgs":true,"family":"Duda","given":"P.B.","email":"","affiliations":[],"preferred":false,"id":450171,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70026583,"text":"70026583 - 2004 - Evaluating the source of streamwater nitrate using δ15N and δ18O in nitrate in two watersheds in New Hampshire, USA","interactions":[],"lastModifiedDate":"2015-05-06T10:12:29","indexId":"70026583","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"Evaluating the source of streamwater nitrate using δ15N and δ18O in nitrate in two watersheds in New Hampshire, USA","docAbstract":"The natural abundance of nitrogen and oxygen isotopes in nitrate can be a powerful tool for identifying the source of nitrate in streamwater in forested watersheds, because the two main sources of nitrate, atmospheric deposition and microbial nitrification, have distinct δ18O values. Using a simple mixing model, we estimated the relative fractions in streamwater derived from these sources for two forested watersheds with markedly different streamwater nitrate outputs. In this study, we monitored δ15N and δ18O of nitrate biweekly in atmospheric deposition and in streamwater for 20 months at the Hubbard Brook Experimental Forest, New Hampshire, USA (moderate nitrogen export), and monthly in streamwater at the Bowl Research Natural Area, New Hampshire, USA (high nitrogen export). For rain, δ18O values ranged from +47 to +77‰ (mean: +58‰) and δ15N from −5 to +1‰ (mean: −3‰); for snow, δ18O values ranged from +52 to +75‰ (mean: +67‰) and δ15N from −3 to +2‰ (mean: −1‰). Streamwater nitrate, in contrast to deposition, had δ18O values between +12 and +33‰ (mean: +18‰) and δ15N between −3 and +6‰ (mean: 0‰). Since nitrate produced by nitrification typically has δ18O values ranging from −5 to +15‰, our field data suggest that most of the nitrate lost from the watersheds in streamflow was nitrified within the catchment. Our results confirm the importance of microbial nitrogen transformations in regulating nitrogen losses from forested ecosystems and suggest that hydrologic storage may be a factor in controlling catchment nitrate losses.
","language":"English","publisher":"Wiley","doi":"10.1002/hyp.5576","issn":"08856087","usgsCitation":"Pardo, L.H., Kendall, C., Pett-Ridge, J., and Chang, C.C., 2004, Evaluating the source of streamwater nitrate using δ15N and δ18O in nitrate in two watersheds in New Hampshire, USA: Hydrological Processes, v. 18, no. 14, p. 2699-2712, https://doi.org/10.1002/hyp.5576.","productDescription":"14 p.","startPage":"2699","endPage":"2712","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":234345,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":208536,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/hyp.5576"}],"volume":"18","issue":"14","noUsgsAuthors":false,"publicationDate":"2004-10-11","publicationStatus":"PW","scienceBaseUri":"505a0c00e4b0c8380cd529b9","contributors":{"authors":[{"text":"Pardo, Linda H.","contributorId":53243,"corporation":false,"usgs":true,"family":"Pardo","given":"Linda","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":410102,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kendall, Carol 0000-0002-0247-3405 ckendall@usgs.gov","orcid":"https://orcid.org/0000-0002-0247-3405","contributorId":1462,"corporation":false,"usgs":true,"family":"Kendall","given":"Carol","email":"ckendall@usgs.gov","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":410099,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Pett-Ridge, Jennifer","contributorId":6726,"corporation":false,"usgs":true,"family":"Pett-Ridge","given":"Jennifer","email":"","affiliations":[],"preferred":false,"id":410100,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Chang, Cecily C.Y.","contributorId":68032,"corporation":false,"usgs":true,"family":"Chang","given":"Cecily","email":"","middleInitial":"C.Y.","affiliations":[],"preferred":false,"id":410101,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70026576,"text":"70026576 - 2004 - The application of an integrated biogeochemical model (PnET-BGC) to five forested watersheds in the Adirondack and Catskill regions of New York","interactions":[],"lastModifiedDate":"2012-03-12T17:20:23","indexId":"70026576","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"The application of an integrated biogeochemical model (PnET-BGC) to five forested watersheds in the Adirondack and Catskill regions of New York","docAbstract":"PnET-BGC is an integrated biogeochemical model formulated to simulate the response of soil and surface waters in northern forest ecosystems to changes in atmospheric deposition and land disturbances. In this study, the model was applied to five intensive study sites in the Adirondack and Catskill regions of New York. Four were in the Adirondacks: Constable Pond, an acid-sensitive watershed; Arbutus Pond, a relatively insensitive watershed; West Pond, an acid-sensitive watershed with extensive wetland coverage; and Willy's Pond, an acid-sensitive watershed with a mature forest. The fifth was Catskills: Biscuit Brook, an acid-sensitive watershed. Results indicated model-simulated surface water chemistry generally agreed with the measured data at all five sites. Model-simulated internal fluxes of major elements at the Arbutus watershed compared well with previously published measured values. In addition, based on the simulated fluxes, element and acid neutralizing capacity (ANC) budgets were developed for each site. Sulphur budgets at each site indicated little retention of inputs of sulphur. The sites also showed considerable variability in retention of NO3-. Land-disturbance history and in-lake processes were found to be important in regulating the output of NO3- via surface waters. Deposition inputs of base cations were generally similar at these sites. Various rates of base cation outputs reflected differences in rates of base cation supply at these sites. Atmospheric deposition was found to be the largest source of acidity, and cation exchange, mineral weathering and in-lake processes served as sources of ANC. ?? 2004 John Wiley and Sons, Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrological Processes","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1002/hyp.5571","issn":"08856087","usgsCitation":"LiJun, C., Driscoll, C.T., Gbondo-Tugbawa, S., Mitchell, M., and Murdoch, P., 2004, The application of an integrated biogeochemical model (PnET-BGC) to five forested watersheds in the Adirondack and Catskill regions of New York: Hydrological Processes, v. 18, no. 14, p. 2631-2650, https://doi.org/10.1002/hyp.5571.","startPage":"2631","endPage":"2650","numberOfPages":"20","costCenters":[],"links":[{"id":234206,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":208455,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/hyp.5571"}],"volume":"18","issue":"14","noUsgsAuthors":false,"publicationDate":"2004-10-11","publicationStatus":"PW","scienceBaseUri":"505ba9c3e4b08c986b3224cb","contributors":{"authors":[{"text":"LiJun, Chen","contributorId":95241,"corporation":false,"usgs":true,"family":"LiJun","given":"Chen","email":"","affiliations":[],"preferred":false,"id":410079,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Driscoll, C. T.","contributorId":47530,"corporation":false,"usgs":false,"family":"Driscoll","given":"C.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":410075,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gbondo-Tugbawa, S.","contributorId":84546,"corporation":false,"usgs":true,"family":"Gbondo-Tugbawa","given":"S.","email":"","affiliations":[],"preferred":false,"id":410078,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Mitchell, M.J.","contributorId":72940,"corporation":false,"usgs":true,"family":"Mitchell","given":"M.J.","email":"","affiliations":[],"preferred":false,"id":410076,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Murdoch, Peter S.","contributorId":73547,"corporation":false,"usgs":true,"family":"Murdoch","given":"Peter S.","affiliations":[],"preferred":false,"id":410077,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70026573,"text":"70026573 - 2004 - Field investigation into unsaturated flow and transport in a fault: Model analyses","interactions":[],"lastModifiedDate":"2012-03-12T17:20:38","indexId":"70026573","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2233,"text":"Journal of Contaminant Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Field investigation into unsaturated flow and transport in a fault: Model analyses","docAbstract":"Results of a fault test performed in the unsaturated zone of Yucca Mountain, Nevada, were analyzed using a three-dimensional numerical model. The fault was explicitly represented as a discrete feature and the surrounding rock was treated as a dual-continuum (fracture-matrix) system. Model calibration against seepage and water-travel-velocity data suggests that lithophysal cavities connected to fractures can considerably enhance the effective fracture porosity and therefore retard water flow in fractures. Comparisons between simulation results and tracer concentration data also indicate that matrix diffusion is an important mechanism for solute transport in unsaturated fractured rock. We found that an increased fault-matrix and fracture-matrix interface areas were needed to match the observed tracer data, which is consistent with previous studies. The study results suggest that the current site-scale model for the unsaturated zone of Yucca Mountain may underestimate radionuclide transport time within the unsaturated zone, because an increased fracture-matrix interface area and the increased effective fracture porosity arising from lithophysal cavities are not considered in the current site-scale model. ?? 2004 Published by Elsevier B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Contaminant Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jconhyd.2004.02.004","issn":"01697722","usgsCitation":"Liu, H., Salve, R., Wang, J., Bodvarsson, G., and Hudson, D., 2004, Field investigation into unsaturated flow and transport in a fault: Model analyses: Journal of Contaminant Hydrology, v. 74, no. 1-4, p. 39-59, https://doi.org/10.1016/j.jconhyd.2004.02.004.","startPage":"39","endPage":"59","numberOfPages":"21","costCenters":[],"links":[{"id":478070,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"http://www.escholarship.org/uc/item/3hq2q80m","text":"External Repository"},{"id":208429,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jconhyd.2004.02.004"},{"id":234170,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"74","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0fc1e4b0c8380cd539e1","contributors":{"authors":[{"text":"Liu, H.-H.","contributorId":14618,"corporation":false,"usgs":true,"family":"Liu","given":"H.-H.","email":"","affiliations":[],"preferred":false,"id":410062,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Salve, R.","contributorId":37516,"corporation":false,"usgs":true,"family":"Salve","given":"R.","affiliations":[],"preferred":false,"id":410063,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Wang, J.-S.","contributorId":67297,"corporation":false,"usgs":true,"family":"Wang","given":"J.-S.","email":"","affiliations":[],"preferred":false,"id":410064,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Bodvarsson, G.S.","contributorId":98045,"corporation":false,"usgs":true,"family":"Bodvarsson","given":"G.S.","email":"","affiliations":[],"preferred":false,"id":410065,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Hudson, D.","contributorId":101064,"corporation":false,"usgs":true,"family":"Hudson","given":"D.","email":"","affiliations":[],"preferred":false,"id":410066,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70026544,"text":"70026544 - 2004 - Airflows and turbulent flux measurements in mountainous terrain: Part 2: Mesoscale effects","interactions":[],"lastModifiedDate":"2018-11-14T07:30:55","indexId":"70026544","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":681,"text":"Agricultural and Forest Meteorology","active":true,"publicationSubtype":{"id":10}},"title":"Airflows and turbulent flux measurements in mountainous terrain: Part 2: Mesoscale effects","docAbstract":"The location of the Niwot Ridge Ameriflux site within the rocky mountains subjects it to airflows which are common in mountainous terrain. In this study, we examine the effects of some of these mesoscale features on local turbulent flux measurements; most notably, the formation of valley/mountain flows and mountain lee-side waves. The valley/mountain flows created local non-stationarities in the wind flow caused by the passage of a lee-side convergence zone (LCZ) in which upslope and downslope flows met in the vicinity of the measurement tower. During June–August, 2001, possible lee-side convergences were flagged for ∼26% of all half-hour daytime flux measurement periods. However, there was no apparent loss of flux during these periods. On some relatively stable, summer nights, turbulence (designated via σw), and scalar fluctuations (temperature and CO2, for example) exhibited periodicities that appeared congruent with passage of low frequency gravity waves (τ ∼ 20 min). Spectral peaks at 0.0008 Hz (20 min) in both vertical velocity and scalar spectra were observed and indicated that 25–50% of the total scalar covariances were accounted for by the low frequency waves. During some periods of strong westerly winds (predominantly in winter), large mountain gravity waves were observed to form. Typically, the flux tower resided within a region of downslope “shooting flow”, which created high turbulence, but had no detrimental effect on local flux measurements based on valid turbulence statistics and nearly complete energy budget closure. Periodically, we found evidence for re-circulating, rotor winds in the simultaneous time series of wind data from the Ameriflux tower site and a second meteorological site situated 8 km upslope and to the West. Only 14% of the half-hour time periods that we examined for a 4 month period in the winter of 2000–2001 indicated the possible existence of rotor winds. On average, energy budget closure was ∼20% less during periods with rotor occurrence compared to those without.
Results from this study demonstrate that the potential exists for relatively rare, yet significant influences of mesoscale wind flow patterns on the local half-hour flux measurements at this site. Occurrence of these events could be detected through examination of normal turbulence statistical parameters.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.agrformet.2004.04.007","issn":"01681923","usgsCitation":"Turnipseed, A., Anderson, D., Burns, S., Blanken, P., and Monson, R.K., 2004, Airflows and turbulent flux measurements in mountainous terrain: Part 2: Mesoscale effects: Agricultural and Forest Meteorology, v. 125, no. 3-4, p. 187-205, https://doi.org/10.1016/j.agrformet.2004.04.007.","productDescription":"19 p.","startPage":"187","endPage":"205","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":234237,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":208476,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.agrformet.2004.04.007"}],"volume":"125","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e92be4b0c8380cd48130","contributors":{"authors":[{"text":"Turnipseed, A.A.","contributorId":23726,"corporation":false,"usgs":true,"family":"Turnipseed","given":"A.A.","email":"","affiliations":[],"preferred":false,"id":409960,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Anderson, D.E.","contributorId":47320,"corporation":false,"usgs":true,"family":"Anderson","given":"D.E.","email":"","affiliations":[],"preferred":false,"id":409961,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Burns, S.","contributorId":50698,"corporation":false,"usgs":true,"family":"Burns","given":"S.","email":"","affiliations":[],"preferred":false,"id":409963,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Blanken, P.D.","contributorId":71354,"corporation":false,"usgs":true,"family":"Blanken","given":"P.D.","affiliations":[],"preferred":false,"id":409964,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Monson, Russell K.","contributorId":48136,"corporation":false,"usgs":true,"family":"Monson","given":"Russell","email":"","middleInitial":"K.","affiliations":[],"preferred":false,"id":409962,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70026540,"text":"70026540 - 2004 - Comparison of in situ uranium KD values with a laboratory determined surface complexation model","interactions":[],"lastModifiedDate":"2012-03-12T17:20:38","indexId":"70026540","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":835,"text":"Applied Geochemistry","active":true,"publicationSubtype":{"id":10}},"title":"Comparison of in situ uranium KD values with a laboratory determined surface complexation model","docAbstract":"Reactive solute transport simulations in groundwater require a large number of parameters to describe hydrologic and chemical reaction processes. Appropriate methods for determining chemical reaction parameters required for reactive solute transport simulations are still under investigation. This work compares U(VI) distribution coefficients (i.e. KD values) measured under field conditions with KD values calculated from a surface complexation model developed in the laboratory. Field studies were conducted in an alluvial aquifer at a former U mill tailings site near the town of Naturita, CO, USA, by suspending approximately 10 g samples of Naturita aquifer background sediments (NABS) in 17-5.1-cm diameter wells for periods of 3 to 15 months. Adsorbed U(VI) on these samples was determined by extraction with a pH 9.45 NaHCO3/Na2CO3 solution. In wells where the chemical conditions in groundwater were nearly constant, adsorbed U concentrations for samples taken after 3 months of exposure to groundwater were indistinguishable from samples taken after 15 months. Measured in situ K D values calculated from the measurements of adsorbed and dissolved U(VI) ranged from 0.50 to 10.6 mL/g and the KD values decreased with increasing groundwater alkalinity, consistent with increased formation of soluble U(VI)-carbonate complexes at higher alkalinities. The in situ K D values were compared with KD values predicted from a surface complexation model (SCM) developed under laboratory conditions in a separate study. A good agreement between the predicted and measured in situ KD values was observed. The demonstration that the laboratory derived SCM can predict U(VI) adsorption in the field provides a critical independent test of a submodel used in a reactive transport model. ?? 2004 Elsevier Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Applied Geochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.apgeochem.2004.03.004","issn":"08832927","usgsCitation":"Curtis, G., Fox, P., Kohler, M., and Davis, J., 2004, Comparison of in situ uranium KD values with a laboratory determined surface complexation model: Applied Geochemistry, v. 19, no. 10, p. 1643-1653, https://doi.org/10.1016/j.apgeochem.2004.03.004.","startPage":"1643","endPage":"1653","numberOfPages":"11","costCenters":[],"links":[{"id":208427,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.apgeochem.2004.03.004"},{"id":234168,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"19","issue":"10","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f86be4b0c8380cd4d0bf","contributors":{"authors":[{"text":"Curtis, G.P.","contributorId":65619,"corporation":false,"usgs":true,"family":"Curtis","given":"G.P.","email":"","affiliations":[],"preferred":false,"id":409948,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fox, P.","contributorId":59213,"corporation":false,"usgs":true,"family":"Fox","given":"P.","email":"","affiliations":[],"preferred":false,"id":409947,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kohler, M.","contributorId":32694,"corporation":false,"usgs":true,"family":"Kohler","given":"M.","affiliations":[],"preferred":false,"id":409946,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Davis, J.A.","contributorId":71694,"corporation":false,"usgs":true,"family":"Davis","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":409949,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70035287,"text":"70035287 - 2004 - Monograph for using paleoflood data in Water Resources Applications","interactions":[],"lastModifiedDate":"2012-03-12T17:21:57","indexId":"70035287","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Monograph for using paleoflood data in Water Resources Applications","docAbstract":"The Environmental and Water Resources Institute (EWRI) Technical Committee on Surface Water Hydrology is sponsoring a Task Committee on Paleoflood Hydrology to prepare a monograph entitled, \"Use of Paleoflood and Historical Data in Water Resources Applications.\" This paper introduces the subject of paleoflood hydrology and discusses the topics, which are expected to be included in the monograph. The procedure for preparing and reviewing the monograph will also be discussed. The paleoflood hydrology monograph will include a discussion of types of hydrologic and paleoflood data, paleostage indicators, flood chronology, modeling methods, interpretation issues, water resources applications and case studies, and research needs. Paleoflood data collection and analysis techniques will be presented, and various applications in water-resources investigations will be provided. An overview of several flood frequency analysis approaches, which consider historical and paleoflood data along with systematic streamflow records, will be presented. The monograph is scheduled for completion and publication in 2001. Copyright ASCE 2004.","largerWorkTitle":"Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships","conferenceTitle":"Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000","conferenceDate":"30 July 2000 through 2 August 2000","conferenceLocation":"Minneapolis, MN","language":"English","doi":"10.1061/40517(2000)123","isbn":"0784405174; 9780784405178","usgsCitation":"Swain, R., and Jarrett, R., 2004, Monograph for using paleoflood data in Water Resources Applications, in Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships, v. 104, Minneapolis, MN, 30 July 2000 through 2 August 2000, https://doi.org/10.1061/40517(2000)123.","costCenters":[],"links":[{"id":215519,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1061/40517(2000)123"},{"id":243330,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"104","noUsgsAuthors":false,"publicationDate":"2012-04-26","publicationStatus":"PW","scienceBaseUri":"505a5e04e4b0c8380cd70760","contributors":{"authors":[{"text":"Swain, R.E.","contributorId":11079,"corporation":false,"usgs":true,"family":"Swain","given":"R.E.","email":"","affiliations":[],"preferred":false,"id":450025,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Jarrett, R.D.","contributorId":36551,"corporation":false,"usgs":true,"family":"Jarrett","given":"R.D.","email":"","affiliations":[],"preferred":false,"id":450026,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70035161,"text":"70035161 - 2004 - Flood hydrology for Dry Creek, Lake County, Northwestern Montana","interactions":[],"lastModifiedDate":"2012-03-12T17:21:54","indexId":"70035161","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Flood hydrology for Dry Creek, Lake County, Northwestern Montana","docAbstract":"Dry Creek drains about 22.6 square kilometers of rugged mountainous terrain upstream from Tabor Dam in the Mission Range near St. Ignatius, Montana. Because of uncertainty about plausible peak discharges and concerns regarding the ability of the Tabor Dam spillway to safely convey these discharges, the flood hydrology for Dry Creek was evaluated on the basis of three hydrologic and geologic methods. The first method involved determining an envelope line relating flood discharge to drainage area on the basis of regional historical data and calculating a 500-year flood for Dry Creek using a regression equation. The second method involved paleoflood methods to estimate the maximum plausible discharge for 35 sites in the study area. The third method involved rainfall-runoff modeling for the Dry Creek basin in conjunction with regional precipitation information to determine plausible peak discharges. All of these methods resulted in estimates of plausible peak discharges that are substantially less than those predicted by the more generally applied probable maximum flood technique. Copyright ASCE 2004.","largerWorkTitle":"Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships","conferenceTitle":"Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000","conferenceDate":"30 July 2000 through 2 August 2000","conferenceLocation":"Minneapolis, MN","language":"English","doi":"10.1061/40517(2000)52","isbn":"0784405174; 9780784405178","usgsCitation":"Parrett, C., and Jarrett, R., 2004, Flood hydrology for Dry Creek, Lake County, Northwestern Montana, in Joint Conference on Water Resource Engineering and Water Resources Planning and Management 2000: Building Partnerships, v. 104, Minneapolis, MN, 30 July 2000 through 2 August 2000, https://doi.org/10.1061/40517(2000)52.","costCenters":[],"links":[{"id":215118,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1061/40517(2000)52"},{"id":242894,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"104","noUsgsAuthors":false,"publicationDate":"2012-04-26","publicationStatus":"PW","scienceBaseUri":"505a10f1e4b0c8380cd53e76","contributors":{"authors":[{"text":"Parrett, C.","contributorId":43400,"corporation":false,"usgs":true,"family":"Parrett","given":"C.","email":"","affiliations":[],"preferred":false,"id":449542,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Jarrett, R.D.","contributorId":36551,"corporation":false,"usgs":true,"family":"Jarrett","given":"R.D.","email":"","affiliations":[],"preferred":false,"id":449541,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70035157,"text":"70035157 - 2004 - The Modular Modeling System (MMS): A modeling framework for water- and environmental-resources management","interactions":[],"lastModifiedDate":"2012-03-12T17:21:56","indexId":"70035157","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"The Modular Modeling System (MMS): A modeling framework for water- and environmental-resources management","docAbstract":"The interdisciplinary nature and increasing complexity of water- and environmental-resource problems require the use of modeling approaches that can incorporate knowledge from a broad range of scientific disciplines. The large number of distributed hydrological and ecosystem models currently available are composed of a variety of different conceptualizations of the associated processes they simulate. Assessment of the capabilities of these distributed models requires evaluation of the conceptualizations of the individual processes, and the identification of which conceptualizations are most appropriate for various combinations of criteria, such as problem objectives, data constraints, and spatial and temporal scales of application. With this knowledge, \"optimal\" models for specific sets of criteria can be created and applied. The U.S. Geological Survey (USGS) Modular Modeling System (MMS) is an integrated system of computer software that has been developed to provide these model development and application capabilities. MMS supports the integration of models and tools at a variety of levels of modular design. These include individual process models, tightly coupled models, loosely coupled models, and fully-integrated decision support systems. A variety of visualization and statistical tools are also provided. MMS has been coupled with the Bureau of Reclamation (BOR) object-oriented reservoir and river-system modeling framework, RiverWare, under a joint USGS-BOR program called the Watershed and River System Management Program. MMS and RiverWare are linked using a shared relational database. The resulting database-centered decision support system provides tools for evaluating and applying optimal resource-allocation and management strategies to complex, operational decisions on multipurpose reservoir systems and watersheds. Management issues being addressed include efficiency of water-resources management, environmental concerns such as meeting flow needs for endangered species, and optimizing operations within the constraints of multiple objectives such as power generation, irrigation, and water conservation. This decision support system approach is being developed, tested, and implemented in the Gunni-son, Yakima, San Juan, Rio Grande, and Truckee River basins of the western United States. Copyright ASCE 2004.","largerWorkTitle":"Bridging the Gap: Meeting the World's Water and Environmental Resources Challenges - Proceedings of the World Water and Environmental Resources Congress 2001","conferenceTitle":"World Water and Environmental Resources Congress 2001","conferenceDate":"20 May 2001 through 24 May 2001","conferenceLocation":"Orlando, FL","language":"English","doi":"10.1061/40569(2001)24","isbn":"0784405697; 9780784405697","usgsCitation":"Leavesley, G., Markstrom, S., and Viger, R., 2004, The Modular Modeling System (MMS): A modeling framework for water- and environmental-resources management, in Bridging the Gap: Meeting the World's Water and Environmental Resources Challenges - Proceedings of the World Water and Environmental Resources Congress 2001, v. 111, Orlando, FL, 20 May 2001 through 24 May 2001, https://doi.org/10.1061/40569(2001)24.","costCenters":[],"links":[{"id":215542,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1061/40569(2001)24"},{"id":243353,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"111","noUsgsAuthors":false,"publicationDate":"2012-04-26","publicationStatus":"PW","scienceBaseUri":"505ba7fae4b08c986b321917","contributors":{"authors":[{"text":"Leavesley, G.H.","contributorId":93895,"corporation":false,"usgs":true,"family":"Leavesley","given":"G.H.","email":"","affiliations":[],"preferred":false,"id":449530,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Markstrom, S.L.","contributorId":76807,"corporation":false,"usgs":true,"family":"Markstrom","given":"S.L.","email":"","affiliations":[],"preferred":false,"id":449528,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Viger, Roland J. 0000-0003-2520-714X","orcid":"https://orcid.org/0000-0003-2520-714X","contributorId":80711,"corporation":false,"usgs":true,"family":"Viger","given":"Roland J.","affiliations":[],"preferred":false,"id":449529,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70026527,"text":"70026527 - 2004 - Use of qualitative and quantitative information in neural networks for assessing agricultural chemical contamination of domestic wells","interactions":[],"lastModifiedDate":"2018-11-14T07:35:41","indexId":"70026527","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2341,"text":"Journal of Hydrologic Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Use of qualitative and quantitative information in neural networks for assessing agricultural chemical contamination of domestic wells","docAbstract":"A neural network analysis of agrichemical occurrence in groundwater was conducted using data from a pilot study of 192 small-diameter drilled and driven wells and 115 dug and bored wells in Illinois, a regional reconnaissance network of 303 wells across 12 Midwestern states, and a study of 687 domestic wells across Iowa. Potential factors contributing to well contamination (e.g., depth to aquifer material, well depth, and distance to cropland) were investigated. These contributing factors were available in either numeric (actual or categorical) or descriptive (yes or no) format. A method was devised to use the numeric and descriptive values simultaneously. Training of the network was conducted using a standard backpropagation algorithm. Approximately 15% of the data was used for testing. Analysis indicated that training error was quite low for most data. Testing results indicated that it was possible to predict the contamination potential of a well with pesticides. However, predicting the actual level of contamination was more difficult. For pesticide occurrence in drilled and driven wells, the network predictions were good. The performance of the network was poorer for predicting nitrate occurrence in dug and bored wells. Although the data set for Iowa was large, the prediction ability of the trained network was poor, due to descriptive or categorical input parameters, compared with smaller data sets such as that for Illinois, which contained more numeric information.
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A.","contributorId":53129,"corporation":false,"usgs":true,"family":"Mishra","given":"A.","email":"","affiliations":[],"preferred":false,"id":409896,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ray, C.","contributorId":40758,"corporation":false,"usgs":true,"family":"Ray","given":"C.","email":"","affiliations":[],"preferred":false,"id":409895,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kolpin, D.W.","contributorId":87565,"corporation":false,"usgs":true,"family":"Kolpin","given":"D.W.","email":"","affiliations":[],"preferred":false,"id":409897,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70026526,"text":"70026526 - 2004 - Effects of nutrient enrichment on the decomposition of wood and associated microbial activity in streams","interactions":[],"lastModifiedDate":"2012-03-12T17:20:39","indexId":"70026526","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1696,"text":"Freshwater Biology","active":true,"publicationSubtype":{"id":10}},"title":"Effects of nutrient enrichment on the decomposition of wood and associated microbial activity in streams","docAbstract":"1. We determined the effects of nutrient enrichment on wood decomposition rates and microbial activity during a 3-year study in two headwater streams at Coweeta Hydrologic Laboratory, NC, U.S.A. After a 1-year pretreatment period, one of the streams was continuously enriched with inorganic nutrients (nitrogen and phosphorus) for 2 years while the other stream served as a reference. We determined the effects of enrichment on both wood veneers and sticks, which have similar carbon quality but differ in physical characteristics (e.g. surface area to volume ratios, presence of bark) that potentially affect microbial colonisation and activity. 2. Oak wood veneers (0.5 mm thick) were placed in streams monthly and allowed to decompose for approximately 90 days. Nutrient addition stimulated ash-free dry mass loss and increased mean nitrogen content, fungal biomass and microbial respiration on veneers in the treatment stream compared with the reference. The magnitude of the response to enrichment was great, with mass loss 6.1 times, and per cent N, fungal biomass and microbial respiration approximately four times greater in the treatment versus reference stream. 3. Decomposition rate and nitrogen content of maple sticks (ca. 1-2 cm diameter) also increased; however, the effect was less pronounced than for veneers. Wood response overall was greater than that determined for leaves in a comparable study, supporting the hypothesis that response to enrichment may be greater for lower quality organic matter (high C:N) than for higher quality (low C:N) substrates. 4. Our results show that moderate nutrient enrichment can profoundly affect decomposition rate and microbial activity on wood in streams. Thus, the timing and availability of wood that provides retention, structure, attachment sites and food in stream ecosystems may be affected by nutrient concentrations raised by human activities.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Freshwater Biology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1365-2427.2004.01281.x","issn":"00465070","usgsCitation":"Gulis, V., Rosemond, A., Suberkropp, K., Weyers, H., and Benstead, J., 2004, Effects of nutrient enrichment on the decomposition of wood and associated microbial activity in streams: Freshwater Biology, v. 49, no. 11, p. 1437-1447, https://doi.org/10.1111/j.1365-2427.2004.01281.x.","startPage":"1437","endPage":"1447","numberOfPages":"11","costCenters":[],"links":[{"id":233945,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":208293,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1365-2427.2004.01281.x"}],"volume":"49","issue":"11","noUsgsAuthors":false,"publicationDate":"2004-10-04","publicationStatus":"PW","scienceBaseUri":"505a076ee4b0c8380cd516c9","contributors":{"authors":[{"text":"Gulis, V.","contributorId":94071,"corporation":false,"usgs":true,"family":"Gulis","given":"V.","email":"","affiliations":[],"preferred":false,"id":409892,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rosemond, A.D.","contributorId":96621,"corporation":false,"usgs":true,"family":"Rosemond","given":"A.D.","affiliations":[],"preferred":false,"id":409893,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Suberkropp, K.","contributorId":10203,"corporation":false,"usgs":true,"family":"Suberkropp","given":"K.","email":"","affiliations":[],"preferred":false,"id":409891,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Weyers, H.S.","contributorId":8592,"corporation":false,"usgs":true,"family":"Weyers","given":"H.S.","email":"","affiliations":[],"preferred":false,"id":409890,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Benstead, J.P.","contributorId":107892,"corporation":false,"usgs":true,"family":"Benstead","given":"J.P.","email":"","affiliations":[],"preferred":false,"id":409894,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70026522,"text":"70026522 - 2004 - Estimation of hydraulic conductivity in an alluvial system using temperatures","interactions":[],"lastModifiedDate":"2018-11-14T08:54:54","indexId":"70026522","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1861,"text":"Ground Water","active":true,"publicationSubtype":{"id":10}},"title":"Estimation of hydraulic conductivity in an alluvial system using temperatures","docAbstract":"Well water temperatures are often collected simultaneously with water levels; however, temperature data are generally considered only as a water quality parameter and are not utilized as an environmental tracer. In this paper, water levels and seasonal temperatures are used to estimate hydraulic conductivities in a stream-aquifer system. To demonstrate this method, temperatures and water levels are analyzed from six observation wells along an example study site, the Russian River in Sonoma County, California. The range in seasonal ground water temperatures in these wells varied from < 0.2??C in two wells to ???8??C in the other four wells from June to October 2000. The temperature probes in the six wells are located at depths between 3.5 and 7.1 m relative to the river channel. Hydraulic conductivities are estimated by matching simulated ground water temperatures to the observed ground water temperatures. An anisotropy of 5 (horizontal to vertical hydraulic conductivity) generally gives the best fit to the observed temperatures. Estimated conductivities vary over an order of magnitude in the six locations analyzed. In some locations, a change in the observed temperature profile occurred during the study, most likely due to deposition of fine-grained sediment and organic matter plugging the streambed. A reasonable fit to this change in the temperature profile is obtained by decreasing the hydraulic conductivity in the simulations. This study demonstrates that seasonal ground water temperatures monitored in observation wells provide an effective means of estimating hydraulic conductivities in alluvial aquifers.","language":"English","publisher":"Wiley","doi":"10.1111/j.1745-6584.2004.t01-7-.x","issn":"0017467X","usgsCitation":"Su, G., Jasperse, J., Seymour, D., and Constantz, J., 2004, Estimation of hydraulic conductivity in an alluvial system using temperatures: Ground Water, v. 42, no. 6, p. 890-901, https://doi.org/10.1111/j.1745-6584.2004.t01-7-.x.","productDescription":"12 ","startPage":"890","endPage":"901","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":234447,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"42","issue":"6","noUsgsAuthors":false,"publicationDate":"2008-10-09","publicationStatus":"PW","scienceBaseUri":"505a0b92e4b0c8380cd527a1","contributors":{"authors":[{"text":"Su, G.W.","contributorId":23314,"corporation":false,"usgs":true,"family":"Su","given":"G.W.","email":"","affiliations":[],"preferred":false,"id":409874,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Jasperse, James","contributorId":64857,"corporation":false,"usgs":false,"family":"Jasperse","given":"James","email":"","affiliations":[],"preferred":false,"id":409877,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Seymour, D.","contributorId":61610,"corporation":false,"usgs":true,"family":"Seymour","given":"D.","email":"","affiliations":[],"preferred":false,"id":409876,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Constantz, J.","contributorId":29953,"corporation":false,"usgs":true,"family":"Constantz","given":"J.","email":"","affiliations":[],"preferred":false,"id":409875,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70026509,"text":"70026509 - 2004 - Stable metal isotopes reveal copper accumulation and loss dynamics in the freshwater bivalve Corbucula","interactions":[],"lastModifiedDate":"2018-11-14T10:13:15","indexId":"70026509","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1565,"text":"Environmental Science & Technology","onlineIssn":"1520-5851","printIssn":"0013-936X","active":true,"publicationSubtype":{"id":10}},"title":"Stable metal isotopes reveal copper accumulation and loss dynamics in the freshwater bivalve Corbucula","docAbstract":"Characterization of uptake and loss dynamics is critical to understanding risks associated with contaminant exposure in aquatic animals. Dynamics are especially important in addressing questions such as why coexisting species in nature accumulate different levels of a contaminant. Here we manipulated copper (Cu) stable isotopic ratios (as an alternative to radioisotopes) to describe for the first time Cu dynamics in a freshwater invertebrate, the bivalve Corbicula fluminea. In the laboratory, Corbicula uptake and loss rate constants were determined from an environmentally realistic waterborne exposure to 65Cu (5.7 μg L-1). That is, we spiked deionized water with Cu that was 99.4% 65Cu. Net tracer uptake was detectable after 1 day and strongly evident after 4 days. Thus, short-term exposures necessary to determine uptake dynamics are feasible with stable isotopes of Cu. In Corbicula, 65Cu depuration was biphasic. An unusually low rate constant of loss (0.0038 d-1) characterized the slow component of efflux, explaining why Corbicula strongly accumulates copper in nature. We incorporated our estimates of rate constants for dissolved 65Cu uptake and physiological efflux into a bioaccumulation model and showed that dietary exposure to Cu is likely an important bioaccumulation pathway for Corbicula.
Water samples from short-screen monitoring wells installed along a 90-km transect in southwestern Kansas were analyzed for major ions, trace elements, isotopes (H, B, C, N, O, S, Sr), and dissolved gases (He, Ne, N2, Ar, O2, CH4) to evaluate the geochemistry, radiocarbon ages, and paleorecharge conditions in the unconfined central High Plains aquifer. The primary reactions controlling water chemistry were dedolomitization, cation exchange, feldspar weathering, and O2 reduction and denitrification. Radiocarbon ages adjusted for C mass transfers ranged from <2.6 ka (14C) B.P. near the water table to 12.8 ± 0.9 ka (14C) B.P. at the base of the aquifer, indicating the unconfined central High Plains aquifer contained a stratified sequence of ground water spanning Holocene time. A cross-sectional model of steady-state ground-water flow, calibrated using radiocarbon ages, is consistent with recharge rates ranging from 0.8 mm/a in areas overlain by loess to 8 mm/a in areas overlain by dune sand. Paleorecharge temperatures ranged from an average of 15.2 ± 0.7 °C for the most recently recharged waters to 11.6 ± 0.4 °C for the oldest waters. The temperature difference between Early and Late Holocene recharge was estimated to be 2.4 ± 0.7 °C, after taking into account variable recharge elevations. Nitrogen isotope data indicate NO3 in paleorecharge (average concentration=193 μM) was derived from a relatively uniform source such as soil N, whereas NO3 in recent recharge (average concentration=885 μM) contained N from varying proportions of fertilizer, manure, and soil N. Deep water samples contained components of N2 derived from atmospheric, denitrification, and deep natural gas sources. Denitrification rates in the aquifer were slow (5 ± 2× 10−3 μmol N L−1 a−1), indicating this process would require >10 ka to reduce the average NO3 concentration in recent recharge to the Holocene background concentration.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.apgeochem.2004.05.003","issn":"08832927","usgsCitation":"McMahon, P., Böhlke, J., and Christenson, S.C., 2004, Geochemistry, radiocarbon ages, and paleorecharge conditions along a transect in the central High Plains aquifer, southwestern Kansas, USA: Applied Geochemistry, v. 19, no. 11, p. 1655-1686, https://doi.org/10.1016/j.apgeochem.2004.05.003.","productDescription":"32 p.","startPage":"1655","endPage":"1686","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":234201,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":208451,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.apgeochem.2004.05.003"}],"country":"United States","state":"Kansas","otherGeospatial":"High Plains Aquifer","volume":"19","issue":"11","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a172de4b0c8380cd553f2","contributors":{"authors":[{"text":"McMahon, P.B. 0000-0001-7452-2379","orcid":"https://orcid.org/0000-0001-7452-2379","contributorId":10762,"corporation":false,"usgs":true,"family":"McMahon","given":"P.B.","affiliations":[],"preferred":false,"id":409798,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Böhlke, J.K. 0000-0001-5693-6455","orcid":"https://orcid.org/0000-0001-5693-6455","contributorId":96696,"corporation":false,"usgs":true,"family":"Böhlke","given":"J.K.","affiliations":[],"preferred":false,"id":409799,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Christenson, S. C.","contributorId":98320,"corporation":false,"usgs":true,"family":"Christenson","given":"S.","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":409800,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70026491,"text":"70026491 - 2004 - Identifying storm flow pathways in a rainforest catchment using hydrological and geochemical modelling","interactions":[],"lastModifiedDate":"2012-03-12T17:20:39","indexId":"70026491","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"Identifying storm flow pathways in a rainforest catchment using hydrological and geochemical modelling","docAbstract":"The hydrological model TOPMODEL is used to assess the water balance and describe flow paths for the 9??73 ha Lutz Creek Catchment in Central Panama. Monte Carlo results are evaluated based on their fit to the observed hydrograph, catchment-averaged soil moisture and stream chemistry. TOPMODEL, with a direct-flow mechanism that is intended to route water through rapid shallow-soil flow, matched observed chemistry and discharge better than the basic version of TOPMODEL and provided a reasonable fit to observed soil moisture and wet-season discharge at both 15-min and daily time-steps. The improvement of simulations with the implementation of a direct-flow component indicates that a storm flow path not represented in the original version of TOPMODEL plays a primary role in the response of Lutz Creek Catchment. This flow path may be consistent with the active and abundant pipeflow that is observed or delayed saturation overland flow. The 'best-accepted' simulations from 1991 to 1997 indicate that around 41% of precipitation becomes direct flow and around 10% is saturation overland flow. Other field observations are needed to constrain evaporative and groundwater losses in the model and to characterize chemical end-members posited in this paper. Published in 2004 by John Wiley and Sons, Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrological Processes","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1002/hyp.1498","issn":"08856087","usgsCitation":"Kinner, D., and Stallard, R., 2004, Identifying storm flow pathways in a rainforest catchment using hydrological and geochemical modelling: Hydrological Processes, v. 18, no. 15, p. 2851-2875, https://doi.org/10.1002/hyp.1498.","startPage":"2851","endPage":"2875","numberOfPages":"25","costCenters":[],"links":[{"id":233942,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":208290,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/hyp.1498"}],"volume":"18","issue":"15","noUsgsAuthors":false,"publicationDate":"2004-06-30","publicationStatus":"PW","scienceBaseUri":"505a385ae4b0c8380cd61538","contributors":{"authors":[{"text":"Kinner, D.A.","contributorId":99265,"corporation":false,"usgs":true,"family":"Kinner","given":"D.A.","email":"","affiliations":[],"preferred":false,"id":409718,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Stallard, R.F.","contributorId":30247,"corporation":false,"usgs":true,"family":"Stallard","given":"R.F.","email":"","affiliations":[],"preferred":false,"id":409717,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70026467,"text":"70026467 - 2004 - Decomposition and organic matter quality in continental peatlands: The ghost of permafrost past","interactions":[],"lastModifiedDate":"2012-03-12T17:20:22","indexId":"70026467","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1478,"text":"Ecosystems","active":true,"publicationSubtype":{"id":10}},"title":"Decomposition and organic matter quality in continental peatlands: The ghost of permafrost past","docAbstract":"Permafrost patterning in boreal peatlands contributes to landscape heterogeneity, as peat plateaus, palsas, and localized permafrost mounds are interspersed among unfrozen bogs and fens. The degradation of localized permafrost in peatlands alters local topography, hydrology, thermal regimes, and plant communities, and creates unique peatland features called \"internal lawns.\" I used laboratory incubations to quantify carbon dioxide (CO 2) production in peat formed under different permafrost regimes (with permafrost, without permafrost, melted permafrost), and explored the relationships among proximate organic matter fractions, nutrient concentrations, and decomposition. Peat within each feature (internal lawn, bog, permafrost mound) is more chemically similar than peat collected within the same province (Alberta, Saskatchewan) or within depth intervals (surface, deep). Internal lawn peat produces more CO2 than the other peatland types. Across peatland features, acid-insoluble material (AIM) and AIM/nitrogen are significant predictors of decomposition. However, within each peatland feature, soluble proximate fractions are better predictors of CO2 production. Permafrost stability in peatlands influences plant and soil environments, which control litter inputs, organic matter quality, and decomposition rates. Spatial patterns of permafrost, as well as ecosystem processes within various permafrost features, should be considered when assessing the fate of soil carbon in northern ecosystems. ?? 2004 Springer Science+Business Media, Inc.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecosystems","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10021-004-0247-z","issn":"14329840","usgsCitation":"Turetsky, M., 2004, Decomposition and organic matter quality in continental peatlands: The ghost of permafrost past: Ecosystems, v. 7, no. 7, p. 740-750, https://doi.org/10.1007/s10021-004-0247-z.","startPage":"740","endPage":"750","numberOfPages":"11","costCenters":[],"links":[{"id":234199,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":208449,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10021-004-0247-z"}],"volume":"7","issue":"7","noUsgsAuthors":false,"publicationDate":"2004-07-21","publicationStatus":"PW","scienceBaseUri":"5059fe13e4b0c8380cd4eae0","contributors":{"authors":[{"text":"Turetsky, M.R.","contributorId":107470,"corporation":false,"usgs":true,"family":"Turetsky","given":"M.R.","email":"","affiliations":[],"preferred":false,"id":409637,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70026460,"text":"70026460 - 2004 - Persistence of pharmaceutical compounds and other organic wastewater contaminants in a conventional drinking-water-treatment plant","interactions":[],"lastModifiedDate":"2018-11-14T10:20:42","indexId":"70026460","displayToPublicDate":"2004-01-01T00:00:00","publicationYear":"2004","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3352,"text":"Science of the Total Environment","active":true,"publicationSubtype":{"id":10}},"title":"Persistence of pharmaceutical compounds and other organic wastewater contaminants in a conventional drinking-water-treatment plant","docAbstract":"In a study conducted by the US Geological Survey and the Centers for Disease Control and Prevention, 24 water samples were collected at selected locations within a drinking-water-treatment (DWT) facility and from the two streams that serve the facility to evaluate the potential for wastewater-related organic contaminants to survive a conventional treatment process and persist in potable-water supplies. Stream-water samples as well as samples of raw, settled, filtered, and finished water were collected during low-flow conditions, when the discharge of effluent from upstream municipal sewage-treatment plants accounted for 37–67% of flow in stream 1 and 10–20% of flow in stream 2. Each sample was analyzed for 106 organic wastewater-related contaminants (OWCs) that represent a diverse group of extensively used chemicals. Forty OWCs were detected in one or more samples of stream water or raw-water supplies in the treatment plant; 34 were detected in more than 10% of these samples. Several of these compounds also were frequently detected in samples of finished water; these compounds include selected prescription and non-prescription drugs and their metabolites, fragrance compounds, flame retardants and plasticizers, cosmetic compounds, and a solvent. The detection of these compounds suggests that they resist removal through conventional water-treatment processes. Other compounds that also were frequently detected in samples of stream water and raw-water supplies were not detected in samples of finished water; these include selected prescription and non-prescription drugs and their metabolites, disinfectants, detergent metabolites, and plant and animal steroids. The non-detection of these compounds indicates that their concentrations are reduced to levels less than analytical detection limits or that they are transformed to degradates through conventional DWT processes. Concentrations of OWCs detected in finished water generally were low and did not exceed Federal drinking-water standards or lifetime health advisories, although such standards or advisories have not been established for most of these compounds. Also, at least 11 and as many as 17 OWCs were detected in samples of finished water. Drinking-water criteria currently are based on the toxicity of individual compounds and not combinations of compounds. Little is known about potential human-health effects associated with chronic exposure to trace levels of multiple OWCs through routes such as drinking water. The occurrence in drinking-water supplies of many of the OWCs analyzed for during this study is unregulated and most of these compounds have not been routinely monitored for in the Nation's source- or potable-water supplies. This study provides the first documentation that many of these compounds can survive conventional water-treatment processes and occur in potable-water supplies. It thereby provides information that can be used in setting research and regulatory priorities and in designing future monitoring programs. The results of this study also indicate that improvements in water-treatment processes may benefit from consideration of the response of OWCs and other trace organic contaminants to specific physical and chemical treatments.
The influences of spiked Zn concentrations (1–40 μmol/g) and equilibration time (˜ 95 d) on the partitioning of Zn between pore water (PW) and sediment were evaluated with estuarine sediments containing two levels (5 and 15 μmol/g) of acid volatile sulfides (AVS). Their influence on Zn bioavailability was also evaluated by a parallel, 10‐d amphipod (Leptocheirus plumulosus) mortality test at 5, 20, and 85 d of equilibration. During the equilibration, AVS increased (up to twofold) with spiked Zn concentration ([Zn]), whereas Zn‐simultaneously extracted metals ([SEM]; Zn with AVS) remained relatively constant. Concentrations of Zn in PW decreased most rapidly during the initial 30 d and by 11‐ to 23‐fold during the whole 95‐d equilibration period. The apparent partitioning coefficient (Kpw, ratio of [Zn] in SEM to PW) increased by 10‐ to 20‐fold with time and decreased with spiked [Zn] in sediments. The decrease of PW [Zn] could be explained by a combination of changes in AVS and redistribution of Zn into more insoluble phases as the sediment aged. Amphipod mortality decreased significantly with the equilibration time, consistent with decrease in dissolved [Zn]. The median lethal concentration (LC50) value (33 μM) in the second bioassay, conducted after 20 d of equilibration, was twofold the LC50 in the initial bioassay at 5 d of equilibration, probably because of the change of dissolved Zn speciation. Sediment bioassay protocols employing a short equilibration time and high spiked metal concentrations could accentuate partitioning of metals to the dissolved phase and shift the pathway for metal exposure toward the dissolved phase.