Ecosystem patterns and disturbance processes at one spatial scale often interact with processes at another scale, and the result of such cross-scale interactions can be nonlinear dynamics with thresholds. Examples of cross-scale pattern-process relationships and interactions among forest dieback, fire, and erosion are illustrated from northern New Mexico (USA) landscapes, where long-term studies have recently documented all of these disturbance processes. For example, environmental stress, operating on individual trees, can cause tree death that is amplified by insect mortality agents to propagate to patch and then landscape or even regional-scale forest dieback. Severe drought and unusual warmth in the southwestern USA since the late 1990s apparently exceeded species-specific physiological thresholds for multiple tree species, resulting in substantial vegetation mortality across millions of hectares of woodlands and forests in recent years. Predictions of forest dieback across spatial scales are constrained by uncertainties associated with: limited knowledge of species-specific physiological thresholds; individual and site-specific variation in these mortality thresholds; and positive feedback loops between rapidly-responding insect herbivore populations and their stressed plant hosts, sometimes resulting in nonlinear “pest” outbreak dynamics. Fire behavior also exhibits nonlinearities across spatial scales, illustrated by changes in historic fire regimes where patch-scale grazing disturbance led to regional-scale collapse of surface fire activity and subsequent recent increases in the scale of extreme fire events in New Mexico. Vegetation dieback interacts with fire activity by modifying fuel amounts and configurations at multiple spatial scales. Runoff and erosion processes are also subject to scale-dependent threshold behaviors, exemplified by ecohydrological work in semiarid New Mexico watersheds showing how declines in ground surface cover lead to non-linear increases in bare patch connectivity and thereby accelerated runoff and erosion at hillslope and watershed scales. Vegetation dieback, grazing, and fire can change land surface properties and cross-scale hydrologic connectivities, directly altering ecohydrological patterns of runoff and erosion. The interactions among disturbance processes across spatial scales can be key drivers in ecosystem dynamics, as illustrated by these studies of recent landscape changes in northern New Mexico. To better anticipate and mitigate accelerating human impacts to the planetary ecosystem at all spatial scales, improvements are needed in our conceptual and quantitative understanding of cross-scale interactions among disturbance processes.
","language":"English","publisher":"Springer","doi":"10.1007/s10021-007-9057-4","usgsCitation":"Allen, C.D., 2007, Interactions across spatial scales among forest dieback, fire, and erosion in northern New Mexico landscapes: Ecosystems, v. 10, no. 5, p. 797-808, https://doi.org/10.1007/s10021-007-9057-4.","productDescription":"12 p.","startPage":"797","endPage":"808","costCenters":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"links":[{"id":488068,"rank":1,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://digitalcommons.unl.edu/natrespapers/104","text":"External Repository"},{"id":238928,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"New Mexico","volume":"10","issue":"5","noUsgsAuthors":false,"publicationDate":"2007-06-20","publicationStatus":"PW","scienceBaseUri":"505a3cbce4b0c8380cd62fbc","contributors":{"authors":[{"text":"Allen, Craig D. 0000-0002-8777-5989 craig_allen@usgs.gov","orcid":"https://orcid.org/0000-0002-8777-5989","contributorId":2597,"corporation":false,"usgs":true,"family":"Allen","given":"Craig","email":"craig_allen@usgs.gov","middleInitial":"D.","affiliations":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true},{"id":290,"text":"Forest and Rangeland Ecosystem Science Center","active":false,"usgs":true}],"preferred":true,"id":428918,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70031421,"text":"70031421 - 2007 - Development of a mercury speciation, fate, and biotic uptake (BIOTRANSPEC) model: Application to Lahontan Reservoir (Nevada, USA)","interactions":[],"lastModifiedDate":"2023-07-18T11:08:19.537351","indexId":"70031421","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1571,"text":"Environmental Toxicology and Chemistry","active":true,"publicationSubtype":{"id":10}},"title":"Development of a mercury speciation, fate, and biotic uptake (BIOTRANSPEC) model: Application to Lahontan Reservoir (Nevada, USA)","docAbstract":"A mathematically linked mercury transport, speciation, kinetic, and simple biotic uptake (BIOTRANSPEC) model has been developed. An extension of the metal transport and speciation (TRANSPEC) model, BIOTRANSPEC estimates the fate and biotic uptake of inorganic (Hg(II)), elemental (Hg(0)) and organic (MeHg) forms of mercury and their species in the dissolved, colloidal (e.g., dissolved organic matter [DOM]), and particulate phases of surface aquatic systems. A pseudo-steady state version of the model was used to describe mercury dynamics in Lahontan Reservoir (near Carson City, NV, USA), where internal loading of the historically deposited mercury is remobilized, thereby maintaining elevated water concentrations. The Carson River is the main source of total mercury (THg), of which more than 90% is tightly bound in a gold-silver-mercury amalgam, to the system through loadings in the spring, with negligible input from the atmospheric deposition. The speciation results suggest that aqueous species are dominated by Hg-DOM, Hg(OH)2, and HgClOH. Sediment-to-water diffusion of MeHg and Hg-DOM accounts for approximately 10% of total loadings to the water column. The water column acts as a net sink for MeHg by reducing its levels through two competitive processes: Uptake by fish, and net MeHg demethylation. Although reservoir sediments produce significant amounts of MeHg (4 g/d), its transport from sediment to water is limited (1.6 g/d), possibly because of its adsorption on metal oxides of iron and manganese at the sediment-water interface. Fish accumulate approximately 45% of the total MeHg mass in the water column, and 9% of total MeHg uptake by fish leaves the system because of fishing. Results from this new model reiterate the previous conclusion that more than 90% of THg input is retained in sediment, which perpetuates elevated water concentrations.
","language":"English","publisher":"SETAC","doi":"10.1897/06-468R.1","issn":"07307268","usgsCitation":"Gandhi, N., Bhavsar, S., Diamond, M., Kuwabara, J.S., Marvin-DePasquale, M.C., and Krabbenhoft, D.P., 2007, Development of a mercury speciation, fate, and biotic uptake (BIOTRANSPEC) model: Application to Lahontan Reservoir (Nevada, USA): Environmental Toxicology and Chemistry, v. 26, no. 11, p. 2260-2273, https://doi.org/10.1897/06-468R.1.","productDescription":"14 p.","startPage":"2260","endPage":"2273","numberOfPages":"14","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":240065,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Nevada","otherGeospatial":"Lahontan Reservoir","volume":"26","issue":"11","noUsgsAuthors":false,"publicationDate":"2007-11-01","publicationStatus":"PW","scienceBaseUri":"505a003ce4b0c8380cd4f66a","contributors":{"authors":[{"text":"Gandhi, N.","contributorId":35543,"corporation":false,"usgs":true,"family":"Gandhi","given":"N.","email":"","affiliations":[],"preferred":false,"id":431436,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bhavsar, S.P.","contributorId":38779,"corporation":false,"usgs":true,"family":"Bhavsar","given":"S.P.","email":"","affiliations":[],"preferred":false,"id":431437,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Diamond, M.L.","contributorId":18578,"corporation":false,"usgs":true,"family":"Diamond","given":"M.L.","email":"","affiliations":[],"preferred":false,"id":431434,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kuwabara, James S. 0000-0003-2502-1601 kuwabara@usgs.gov","orcid":"https://orcid.org/0000-0003-2502-1601","contributorId":3374,"corporation":false,"usgs":true,"family":"Kuwabara","given":"James","email":"kuwabara@usgs.gov","middleInitial":"S.","affiliations":[{"id":651,"text":"Western Ecological Research Center","active":true,"usgs":true}],"preferred":true,"id":431438,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Marvin-DePasquale, Mark C.","contributorId":38655,"corporation":false,"usgs":true,"family":"Marvin-DePasquale","given":"Mark","email":"","middleInitial":"C.","affiliations":[],"preferred":false,"id":431435,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Krabbenhoft, David P. 0000-0003-1964-5020 dpkrabbe@usgs.gov","orcid":"https://orcid.org/0000-0003-1964-5020","contributorId":1658,"corporation":false,"usgs":true,"family":"Krabbenhoft","given":"David","email":"dpkrabbe@usgs.gov","middleInitial":"P.","affiliations":[{"id":37947,"text":"Upper Midwest Water Science Center","active":true,"usgs":true},{"id":677,"text":"Wisconsin Water Science Center","active":true,"usgs":true},{"id":37464,"text":"WMA - Laboratory & Analytical Services Division","active":true,"usgs":true},{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":431439,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70031412,"text":"70031412 - 2007 - Ammonia-oxidizing bacterial community composition in estuarine and oceanic environments assessed using a functional gene microarray","interactions":[],"lastModifiedDate":"2018-10-11T19:10:15","indexId":"70031412","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1548,"text":"Environmental Microbiology","active":true,"publicationSubtype":{"id":10}},"title":"Ammonia-oxidizing bacterial community composition in estuarine and oceanic environments assessed using a functional gene microarray","docAbstract":"The relationship between environmental factors and functional gene diversity of ammonia-oxidizing bacteria (AOB) was investigated across a transect from the freshwater portions of the Chesapeake Bay and Choptank River out into the Sargasso Sea. Oligonucleotide probes (70-bp) designed to represent the diversity of ammonia monooxygenase (amoA) genes from Chesapeake Bay clone libraries and cultivated AOB were used to construct a glass slide microarray. Hybridization patterns among the probes in 14 samples along the transect showed clear variations in amoA community composition. Probes representing uncultivated members of the Nitrosospira-like AOB dominated the probe signal, especially in the more marine samples. Of the cultivated species, only Nitrosospira briensis was detected at appreciable levels. Discrimination analysis of hybridization signals detected two guilds. Guild 1 was dominated by the marine Nitrosospira-like probe signal, and Guild 2???s largest contribution was from upper bay (freshwater) sediment probes. Principal components analysis showed that Guild 1 was positively correlated with salinity, temperature and chlorophyll a concentration, while Guild 2 was positively correlated with concentrations of oxygen, dissolved organic carbon, and particulate nitrogen and carbon, suggesting that different amoA sequences represent organisms that occupy different ecological niches within the estuarine/marine environment. The trend from most diversity of AOB in the upper estuary towards dominance of a single type in the polyhaline region of the Bay is consistent with the declining importance of AOB with increasing salinity, and with the idea that AO-Archaea are the more important ammonia oxidizers in the ocean.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Microbiology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1462-2920.2007.01371.x","issn":"14622912","usgsCitation":"Ward, B., Eveillard, D., Kirshtein, J.D., Nelson, J., Voytek, M.A., and Jackson, G.A., 2007, Ammonia-oxidizing bacterial community composition in estuarine and oceanic environments assessed using a functional gene microarray: Environmental Microbiology, v. 9, no. 10, p. 2522-2538, https://doi.org/10.1111/j.1462-2920.2007.01371.x.","productDescription":"17 p.","startPage":"2522","endPage":"2538","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":239923,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212435,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1462-2920.2007.01371.x"}],"country":"United States","volume":"9","issue":"10","noUsgsAuthors":false,"publicationDate":"2007-06-27","publicationStatus":"PW","scienceBaseUri":"5059e9bee4b0c8380cd48416","contributors":{"authors":[{"text":"Ward, B.B.","contributorId":7023,"corporation":false,"usgs":true,"family":"Ward","given":"B.B.","email":"","affiliations":[],"preferred":false,"id":431393,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Eveillard, D.","contributorId":78549,"corporation":false,"usgs":true,"family":"Eveillard","given":"D.","email":"","affiliations":[],"preferred":false,"id":431398,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kirshtein, Julie D.","contributorId":26033,"corporation":false,"usgs":true,"family":"Kirshtein","given":"Julie","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":431394,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Nelson, J.D.","contributorId":58101,"corporation":false,"usgs":true,"family":"Nelson","given":"J.D.","email":"","affiliations":[],"preferred":false,"id":431396,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Voytek, Mary A.","contributorId":91943,"corporation":false,"usgs":true,"family":"Voytek","given":"Mary","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":431395,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Jackson, G. A.","contributorId":73138,"corporation":false,"usgs":true,"family":"Jackson","given":"G.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":431397,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70031407,"text":"70031407 - 2007 - Ordination of breeding birds in relation to environmental gradients in three southeastern United States floodplain forests","interactions":[],"lastModifiedDate":"2012-03-12T17:21:14","indexId":"70031407","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3751,"text":"Wetlands Ecology and Management","active":true,"publicationSubtype":{"id":10}},"title":"Ordination of breeding birds in relation to environmental gradients in three southeastern United States floodplain forests","docAbstract":"We used an ordination approach to identify factors important to the organization of breeding bird communities in three floodplains: Cache River, Arkansas (AR), Iatt Creek, Louisiana (LA), and the Coosawhatchie River, South Carolina (SC), USA. We used 5-min point counts to sample birds in each study area each spring from 1995 to 1998, and measured ground-surface elevations and a suite of other habitat variables to investigate bird distributions and community characteristics in relation to important environmental gradients. In both AR and SC, the average number of Neotropical migrant species detected was lowest in semipermanently flooded Nyssa aquatica Linnaeus habitats and greatest in the highest elevation floodplain zone. Melanerpes carolinus Linnaeus, Protonotaria citrea Boddaert, Quiscalus quiscula Linnaeus, and other species were more abundant in N. aquatica habitats, whereas Wilsonia citrina Boddaert, Oporornis formosus Wilson, Vireo griseus Boddaert, and others were more abundant in drier floodplain zones. In LA, there were no significant differences in community metrics or bird species abundances among forest types. Canonical correspondence analyses revealed that structural development of understory vegetation was the most important factor affecting bird distributions in all three study areas; however, potential causes of these structural gradients differed. In AR and SC, differences in habitat structure were related to the hydrologic gradient, as indexed by ground-surface elevation. In LA, structural variations were related mainly to the frequency of canopy gaps. Thus, bird communities in all three areas appeared to be organized primarily in response to repeated localized disturbance. Our results suggest that regular disturbance due to flooding plays an important role in structuring breeding bird communities in floodplains subject to prolonged inundation, whereas other agents of disturbance (e.g., canopy gaps) may be more important in headwater systems subject to only short-duration flooding. Management for avian community integrity in these systems should strive to maintain forest zonation and natural disturbance regimes. ?? 2007 Springer Science+Business Media B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Wetlands Ecology and Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s11273-007-9040-z","issn":"09234861","usgsCitation":"Wakeley, J., Guilfoyle, M., Antrobus, T.J., Fischer, R., Barrow, W., and Hamel, P., 2007, Ordination of breeding birds in relation to environmental gradients in three southeastern United States floodplain forests: Wetlands Ecology and Management, v. 15, no. 5, p. 417-439, https://doi.org/10.1007/s11273-007-9040-z.","startPage":"417","endPage":"439","numberOfPages":"23","costCenters":[],"links":[{"id":212349,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s11273-007-9040-z"},{"id":239820,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"15","issue":"5","noUsgsAuthors":false,"publicationDate":"2007-05-22","publicationStatus":"PW","scienceBaseUri":"505a6f44e4b0c8380cd759f8","contributors":{"authors":[{"text":"Wakeley, J.S.","contributorId":103996,"corporation":false,"usgs":true,"family":"Wakeley","given":"J.S.","email":"","affiliations":[],"preferred":false,"id":431375,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Guilfoyle, M.P.","contributorId":59145,"corporation":false,"usgs":true,"family":"Guilfoyle","given":"M.P.","email":"","affiliations":[],"preferred":false,"id":431372,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Antrobus, T. J.","contributorId":63117,"corporation":false,"usgs":true,"family":"Antrobus","given":"T.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":431373,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Fischer, R.A.","contributorId":21763,"corporation":false,"usgs":true,"family":"Fischer","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":431371,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Barrow, W.C. Jr. 0000-0003-4671-2823","orcid":"https://orcid.org/0000-0003-4671-2823","contributorId":11183,"corporation":false,"usgs":true,"family":"Barrow","given":"W.C.","suffix":"Jr.","affiliations":[],"preferred":false,"id":431370,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Hamel, P.B.","contributorId":88444,"corporation":false,"usgs":true,"family":"Hamel","given":"P.B.","email":"","affiliations":[],"preferred":false,"id":431374,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70030804,"text":"70030804 - 2007 - Effects of imposed salinity gradients on dissimilatory arsenate reduction, sulfate reduction, and other microbial processes in sediments from two California soda lakes","interactions":[],"lastModifiedDate":"2023-07-28T11:57:59.353724","indexId":"70030804","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":850,"text":"Applied and Environmental Microbiology","active":true,"publicationSubtype":{"id":10}},"title":"Effects of imposed salinity gradients on dissimilatory arsenate reduction, sulfate reduction, and other microbial processes in sediments from two California soda lakes","docAbstract":"[1] Chemical conditions were perturbed in an aquifer with an ambient pH of 5.9 and wastewater-derived adsorbed zinc (Zn) and phosphate (P) contamination by injecting a pulse of amended groundwater. The injected groundwater had low concentrations of dissolved Zn and P, a pH value of 4.5 resulting from equilibration with carbon dioxide gas, and added potassium bromide (KBr). Downgradient of the injection, breakthrough of nonreactive Br and total dissolved carbonate concentrations in excess of ambient values (excess TCO2) were accompanied by a decrease in pH values and over twentyfold increases in dissolved Zn concentrations above preinjection values. Peak concentrations of Br and excess TCO2 were followed by slow increases in pH values accompanied by significant increases in dissolved P above preinjection concentrations. The injected tracers mobilized a significant mass of wastewater-derived Zn. Reactive transport simulations incorporating surface complexation models for adsorption of Zn, P, hydrogen ions, and major cations onto the aquifer sediments, calibrated using laboratory experimental data, captured most of the important trends observed during the experiment. These include increases in Zn concentrations in response to the pH perturbation, perturbations in major cation concentrations, attenuation of the pH perturbation with transport distance, and increases in alkalinity with transport distance. Observed desorption of P in response to chemical perturbations was not predicted, possibly because of a disparity between the range of chemical conditions in the calibration data set and those encountered during the field experiment. Zinc and P desorbed rapidly in response to changing chemical conditions despite decades of contact with the sediments. Surface complexation models with relatively few parameters in the form of logK values and site concentrations show considerable promise for describing the influence of variable chemistry on the transport of adsorbing contaminants.
We compared streamflow in basins under the combined impacts of an upland dam and groundwater pumping withdrawals, by examining streamflow in the presence and absence of each impact. As a qualitative analysis, inter-watershed streamflow comparisons were performed for several rivers flowing into the east side of the Central Valley, CA. Results suggest that, in the absence of upland dams supporting large reservoirs, some reaches of these rivers might develop ephemeral streamflow in late summer. As a quantitative analysis, we conducted a series of streamflow/groundwater simulations (using MODFLOW-2000 plus the streamflow routing package, SFR1) for a representative hypothetical watershed, with an upland dam and groundwater pumping in the downstream basin, under humid, semi-arid, and arid conditions. As a result of including the impact of groundwater pumping, post-dam removal simulated streamflow was significantly less than natural streamflow. The model predicts extensive ephemeral conditions in the basin during September for both the arid and semi-arid cases. The model predicts continued perennial conditions in the humid case, but spatially weighted, average streamflow of only 71% of natural September streamflow, as a result of continued pumping after dam removal.
Numerous models are in widespread use for the estimation of soil water retention from more easily measured textural data. Improved models are needed for better prediction and wider applicability. We developed a basic framework from which new and existing models can be derived to facilitate improvements. Starting from the assumption that every particle has a characteristic dimension R associated uniquely with a matric pressure ψ and that the form of the ψ–R relation is the defining characteristic of each model, this framework leads to particular models by specification of geometric relationships between pores and particles. Typical assumptions are that particles are spheres, pores are cylinders with volume equal to the associated particle volume times the void ratio, and that the capillary inverse proportionality between radius and matric pressure is valid. Examples include fixed-pore-shape and fixed-pore-length models. We also developed alternative versions of the model of Arya and Paris that eliminate its interval-size dependence and other problems. The alternative models are calculable by direct application of algebraic formulas rather than manipulation of data tables and intermediate results, and they easily combine with other models (e.g., incorporating structural effects) that are formulated on a continuous basis. Additionally, we developed a family of models based on the same pore geometry as the widely used unsaturated hydraulic conductivity model of Mualem. Predictions of measurements for different suitable media show that some of the models provide consistently good results and can be chosen based on ease of calculations and other factors.
","language":"English","publisher":"Soil Science Society of America","doi":"10.2136/vzj2007.0019","issn":"15391663","usgsCitation":"Nimmo, J.R., Herkelrath, W.N., and Laguna, L., 2007, Physically based estimation of soil water retention from textural data: General framework, new models, and streamlined existing models: Vadose Zone Journal, v. 6, no. 4, p. 766-773, https://doi.org/10.2136/vzj2007.0019.","productDescription":"8 p.","startPage":"766","endPage":"773","numberOfPages":"8","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":498910,"rank":2,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.2136/vzj2007.0019","text":"Publisher Index Page"},{"id":239755,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"6","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a7af0e4b0c8380cd7918e","contributors":{"authors":[{"text":"Nimmo, John R. 0000-0001-8191-1727 jrnimmo@usgs.gov","orcid":"https://orcid.org/0000-0001-8191-1727","contributorId":757,"corporation":false,"usgs":true,"family":"Nimmo","given":"John","email":"jrnimmo@usgs.gov","middleInitial":"R.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true},{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true}],"preferred":true,"id":431354,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Herkelrath, William N. 0000-0002-6149-5524 wnherkel@usgs.gov","orcid":"https://orcid.org/0000-0002-6149-5524","contributorId":2612,"corporation":false,"usgs":true,"family":"Herkelrath","given":"William","email":"wnherkel@usgs.gov","middleInitial":"N.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":431355,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Laguna, Luna","contributorId":12694,"corporation":false,"usgs":true,"family":"Laguna","given":"Luna","email":"","affiliations":[],"preferred":false,"id":431353,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70029838,"text":"70029838 - 2007 - Determining metal assimilation efficiency in aquatic invertebrates using enriched stable metal isotope tracers","interactions":[],"lastModifiedDate":"2023-08-03T11:54:24.514896","indexId":"70029838","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":874,"text":"Aquatic Toxicology","active":true,"publicationSubtype":{"id":10}},"title":"Determining metal assimilation efficiency in aquatic invertebrates using enriched stable metal isotope tracers","docAbstract":"We employ a novel approach that combines pulse-chase feeding and multi-labelled stable isotopes to determine gut passage time (GPT), gut retention time (GRT), food ingestion rate (IR) and assimilation efficiency (AE) of three trace elements for a freshwater gastropod. Lettuce isotopically enriched in 53Cr, 65Cu and 106Cd was fed for 2 h to Lymnaea stagnalis. The release of tracers in feces and water was monitored for 48 h, during which unlabelled lettuce was provided ad libidum. The first defecation of 53Cr occurred after 5 h of depuration (GPT), whereas 90% of the ingested 53Cr was recovered in the feces after 22.5 h of depuration (GRT). 53Chromium was not significantly accumulated in the soft tissues upon exposure. In contrast, 65Cu and 106Cd assimilation was detectable for most experimental snails, i.e., 65/63Cu and 106/114Cd ratios in exposed snails were higher than those for controls. Food IR during the labelled feeding phase was 0.16 ± 0.07 g g−1 d−1. IR was inferred from the amount of 53Cr egested in the feces during depuration and the concentration of 53Cr in the labelled lettuce. Assimilation efficiencies (±95% CI) determined using mass balance calculations were 84 ± 4% for Cu and 85 ± 3% for Cd. The ratio method yields similar AE estimates. Expanding the application of this novel stable isotope tracer technique to other metals in a wide variety of species will provide unique opportunities to evaluate the interplay between digestive processes and dietary influx of metals. Understanding the biological processes that modulate dietborne metal uptake is crucial to assess the toxicity of dietborne metals.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.aquatox.2007.03.016","issn":"0166445X","usgsCitation":"Croteau, M.N., Luoma, S.N., and Pellet, B., 2007, Determining metal assimilation efficiency in aquatic invertebrates using enriched stable metal isotope tracers: Aquatic Toxicology, v. 83, no. 2, p. 116-125, https://doi.org/10.1016/j.aquatox.2007.03.016.","productDescription":"10 p.","startPage":"116","endPage":"125","numberOfPages":"10","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":240315,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"83","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fff0e4b0c8380cd4f4b2","contributors":{"authors":[{"text":"Croteau, Marie Noele 0000-0003-0346-3580 mcroteau@usgs.gov","orcid":"https://orcid.org/0000-0003-0346-3580","contributorId":895,"corporation":false,"usgs":true,"family":"Croteau","given":"Marie","email":"mcroteau@usgs.gov","middleInitial":"Noele","affiliations":[{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true},{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":424540,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Luoma, Samuel N. 0000-0001-5443-5091 snluoma@usgs.gov","orcid":"https://orcid.org/0000-0001-5443-5091","contributorId":2287,"corporation":false,"usgs":true,"family":"Luoma","given":"Samuel","email":"snluoma@usgs.gov","middleInitial":"N.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":424541,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Pellet, B.","contributorId":99377,"corporation":false,"usgs":true,"family":"Pellet","given":"B.","email":"","affiliations":[],"preferred":false,"id":424542,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030743,"text":"70030743 - 2007 - A simulation-based approach for estimating premining water quality: Red Mountain Creek, Colorado","interactions":[],"lastModifiedDate":"2018-10-17T11:22:55","indexId":"70030743","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"A simulation-based approach for estimating premining water quality: Red Mountain Creek, Colorado","docAbstract":"Regulatory agencies are often charged with the task of setting site-specific numeric water quality standards for impaired streams. This task is particularly difficult for streams draining highly mineralized watersheds with past mining activity. Baseline water quality data obtained prior to mining are often non-existent and application of generic water quality standards developed for unmineralized watersheds is suspect given the geology of most watersheds affected by mining. Various approaches have been used to estimate premining conditions, but none of the existing approaches rigorously consider the physical and geochemical processes that ultimately determine instream water quality. An approach based on simulation modeling is therefore proposed herein. The approach utilizes synoptic data that provide spatially-detailed profiles of concentration, streamflow, and constituent load along the study reach. This field data set is used to calibrate a reactive stream transport model that considers the suite of physical and geochemical processes that affect constituent concentrations during instream transport. A key input to the model is the quality and quantity of waters entering the study reach. This input is based on chemical analyses available from synoptic sampling and observed increases in streamflow along the study reach. Given the calibrated model, additional simulations are conducted to estimate premining conditions. In these simulations, the chemistry of mining-affected sources is replaced with the chemistry of waters that are thought to be unaffected by mining (proximal, premining analogues). The resultant simulations provide estimates of premining water quality that reflect both the reduced loads that were present prior to mining and the processes that affect these loads as they are transported downstream. This simulation-based approach is demonstrated using data from Red Mountain Creek, Colorado, a small stream draining a heavily-mined watershed. Model application to the premining problem for Red Mountain Creek is based on limited field reconnaissance and chemical analyses; additional field work and analyses may be needed to develop definitive, quantitative estimates of premining water quality.","language":"English","publisher":"Elsevier","doi":"10.1016/j.apgeochem.2007.03.054","issn":"08832927","usgsCitation":"Runkel, R.L., Kimball, B.A., Walton-Day, K., and Verplanck, P.L., 2007, A simulation-based approach for estimating premining water quality: Red Mountain Creek, Colorado: Applied Geochemistry, v. 22, no. 9, p. 1899-1918, https://doi.org/10.1016/j.apgeochem.2007.03.054.","productDescription":"20 p.","startPage":"1899","endPage":"1918","numberOfPages":"20","costCenters":[{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":238855,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211552,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.apgeochem.2007.03.054"}],"country":"United States","state":"Colorado","otherGeospatial":"Red Mountain Creek","volume":"22","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e598e4b0c8380cd46e66","contributors":{"authors":[{"text":"Runkel, Robert L. 0000-0003-3220-481X runkel@usgs.gov","orcid":"https://orcid.org/0000-0003-3220-481X","contributorId":685,"corporation":false,"usgs":true,"family":"Runkel","given":"Robert","email":"runkel@usgs.gov","middleInitial":"L.","affiliations":[{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true}],"preferred":true,"id":428487,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kimball, Briant A","contributorId":118888,"corporation":false,"usgs":true,"family":"Kimball","given":"Briant","email":"","middleInitial":"A","affiliations":[],"preferred":false,"id":428486,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Walton-Day, Katherine 0000-0002-9146-6193 kwaltond@usgs.gov","orcid":"https://orcid.org/0000-0002-9146-6193","contributorId":1245,"corporation":false,"usgs":true,"family":"Walton-Day","given":"Katherine","email":"kwaltond@usgs.gov","affiliations":[{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true}],"preferred":false,"id":428485,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Verplanck, Philip L. 0000-0002-3653-6419 plv@usgs.gov","orcid":"https://orcid.org/0000-0002-3653-6419","contributorId":728,"corporation":false,"usgs":true,"family":"Verplanck","given":"Philip","email":"plv@usgs.gov","middleInitial":"L.","affiliations":[{"id":171,"text":"Central Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":428488,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70029699,"text":"70029699 - 2007 - Nitrification in the euphotic zone as evidenced by nitrate dual isotopic composition: Observations from Monterey Bay, California","interactions":[],"lastModifiedDate":"2018-10-17T12:30:04","indexId":"70029699","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1836,"text":"Global Biogeochemical Cycles","active":true,"publicationSubtype":{"id":10}},"title":"Nitrification in the euphotic zone as evidenced by nitrate dual isotopic composition: Observations from Monterey Bay, California","docAbstract":"Coupled measurements of nitrate (NO3−), nitrogen (N), and oxygen (O) isotopic composition (δ15NNO3 and δ18ONO3) were made in surface waters of Monterey Bay to investigate multiple N cycling processes occurring within surface waters. Profiles collected throughout the year at three sites exhibit a wide range of values, suggesting simultaneous and variable influence of both phytoplankton NO3− assimilation and nitrification within the euphotic zone. Specifically, increases in δ18ONO3 were consistently greater than those in δ15NNO3. A coupled isotope steady state box model was used to estimate the amount of NO3− supplied by nitrification in surface waters relative to that supplied from deeper water. The model highlights the importance of the branching reaction during ammonium (NH4+) consumption, in which NH4+ either serves as a substrate for regenerated production or for nitrification. Our observations indicate that a previously unrecognized proportion of nitrate‐based productivity, on average 15 to 27%, is supported by nitrification in surface waters and should not be considered new production. This work also highlights the need for a better understanding of isotope effects of NH4+ oxidation, NH4+ assimilation, and NO3− assimilation in marine environments.
Climate scientists have concluded that the earth’s surface air temperature warmed by 0.6 °C during the 20th century, and that warming induced by increasing concentrations of greenhouse gases is likely to continue in the 21st century, accompanied by changes in the hydrologic cycle. Climate change has important implications in the Catskill region of southeastern New York State, because the region is a source of water supply for New York City. We used the non-parametric Mann–Kendall test to evaluate annual, monthly, and multi-month trends in air temperature, precipitation amount, stream runoff, and potential evapotranspiration (PET) in the region during 1952–2005 based on data from 9 temperature sites, 12 precipitation sites, and 8 stream gages. A general pattern of warming temperatures and increased precipitation, runoff, and PET is evident in the region. Regional annual mean air temperature increased significantly by 0.6 °C per 50 years during the period; the greatest increases and largest number of significant upward trends were in daily minimum air temperature. Daily maximum air temperature showed the greatest increase during February through April, whereas minimum air temperature showed the greatest increase during May through September. Regional mean precipitation increased significantly by 136 mm per 50 years, nearly double that of the regional mean increase in runoff, which was not significant. Regional mean PET increased significantly by 19 mm per 50 years, about one-seventh that of the increase in precipitation amount, and broadly consistent with increased runoff during 1952–2005, despite the lack of significance in the mean regional runoff trend. Peak snowmelt as approximated by the winter–spring center of volume of stream runoff generally shifted from early April at the beginning of the record to late March at the end of the record, consistent with a decreasing trend in April runoff and an increasing trend in maximum March air temperature. This change indicates an increased supply of water to reservoirs earlier in the year. Additionally, the supply of water to reservoirs at the beginning of winter is greater as indicated by the timing of the greatest increases in precipitation and runoff—both occurred during summer and fall. The future balance between changes in air temperature and changes in the timing and amount of precipitation in the region will have important implications for the available water supply in the region.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.jhydrol.2006.12.019","issn":"00221694","usgsCitation":"Burns, D.A., Klaus, J., and McHale, M.R., 2007, Recent climate trends and implications for water resources in the Catskill Mountain region, New York, USA: Journal of Hydrology, v. 336, no. 1-2, p. 155-170, https://doi.org/10.1016/j.jhydrol.2006.12.019.","productDescription":"16 p.","startPage":"155","endPage":"170","numberOfPages":"16","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":240479,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"New York","otherGeospatial":"Catskill region","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n -75.3607177734375,\n 42.004407212963585\n ],\n [\n -75.3277587890625,\n 41.96357478222518\n ],\n [\n -75.26184082031249,\n 41.93088998442502\n ],\n [\n -75.2508544921875,\n 41.87774145109676\n ],\n [\n -75.1959228515625,\n 41.85319643776675\n ],\n [\n -75.157470703125,\n 41.84501267270692\n ],\n [\n -75.1080322265625,\n 41.832735062152615\n ],\n [\n -75.1025390625,\n 41.78769700539063\n ],\n [\n -75.047607421875,\n 41.73852846935917\n ],\n [\n -75.05859375,\n 41.66060124302088\n ],\n [\n -75.05859375,\n 41.60722821271717\n ],\n [\n -75.03662109375,\n 41.549700145132725\n ],\n [\n -74.9871826171875,\n 41.492120839687786\n ],\n [\n -74.937744140625,\n 41.47154438707647\n ],\n [\n -74.8883056640625,\n 41.45507852101139\n ],\n [\n -74.8388671875,\n 41.430371882652814\n ],\n [\n -74.77294921875,\n 41.42625319507272\n ],\n [\n -74.7344970703125,\n 41.413895564677304\n ],\n [\n -74.7015380859375,\n 41.372686481864655\n ],\n [\n -74.68505859374999,\n 41.35207214451295\n ],\n [\n -74.50927734375,\n 41.281934557995356\n ],\n [\n -74.3719482421875,\n 41.33970040774419\n ],\n [\n -74.102783203125,\n 41.430371882652814\n ],\n [\n -73.85009765625,\n 41.51680395810118\n ],\n [\n -73.7841796875,\n 41.590796851056005\n ],\n [\n -73.7017822265625,\n 41.70982942509964\n ],\n [\n -73.6468505859375,\n 41.83682786072714\n ],\n [\n -73.6138916015625,\n 42.04521345501039\n ],\n [\n -73.6688232421875,\n 42.313877566161864\n ],\n [\n -73.707275390625,\n 42.45588764197166\n ],\n [\n -73.7841796875,\n 42.742978093466434\n ],\n [\n -73.8885498046875,\n 42.867912483915305\n ],\n [\n -74.1522216796875,\n 42.93631775765237\n ],\n [\n -74.498291015625,\n 42.93631775765237\n ],\n [\n -74.86083984375,\n 42.93631775765237\n ],\n [\n -75.1409912109375,\n 42.81555136172695\n ],\n [\n -75.25634765625,\n 42.68243539838623\n ],\n [\n -75.35522460937499,\n 42.459940352216556\n ],\n [\n -75.3607177734375,\n 42.004407212963585\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"336","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a95f0e4b0c8380cd81d0b","contributors":{"authors":[{"text":"Burns, Douglas A. 0000-0001-6516-2869","orcid":"https://orcid.org/0000-0001-6516-2869","contributorId":29450,"corporation":false,"usgs":true,"family":"Burns","given":"Douglas","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":423932,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Klaus, Julian","contributorId":173770,"corporation":false,"usgs":false,"family":"Klaus","given":"Julian","email":"","affiliations":[{"id":7107,"text":"Univ. of Freiburg, Germany","active":true,"usgs":false}],"preferred":false,"id":423934,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"McHale, Michael R. 0000-0003-3780-1816 mmchale@usgs.gov","orcid":"https://orcid.org/0000-0003-3780-1816","contributorId":1735,"corporation":false,"usgs":true,"family":"McHale","given":"Michael","email":"mmchale@usgs.gov","middleInitial":"R.","affiliations":[{"id":474,"text":"New York Water Science Center","active":true,"usgs":true}],"preferred":true,"id":423933,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70029706,"text":"70029706 - 2007 - Isotopic characterization of three groundwater recharge sources and inferences for selected aquifers in the upper Klamath Basin of Oregon and California, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:21:05","indexId":"70029706","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Isotopic characterization of three groundwater recharge sources and inferences for selected aquifers in the upper Klamath Basin of Oregon and California, USA","docAbstract":"Stable isotope (??D and ??18O) signatures of three principal groundwater recharge areas in the 21,000-km2 upper Klamath Basin are used to infer recharge sources for aquifers in the interior parts of the basin. Two of the principal recharge areas, the Cascade Range on the western and southern margin of the basin and uplands along the eastern margin, are defined by mean annual precipitation that exceeds approximately 60 cm. A third recharge area coincides with the extensive irrigation canal system in the south central part of the basin. The stable isotope signature for Cascade Range groundwater falls near the global meteoric water line (GMWL). The stable isotope signature for the groundwater of the eastern basin uplands also falls near the GMWL, but is depleted in heavy isotopes relative to the Cascade Range groundwater. The stable isotope signature for water from the irrigation canal system deviates from the GMWL in a manner indicative of fractionation by evaporation. Groundwater provenance was previously unknown for two aquifers of interest: that supplying deep (225-792 m), large-capacity irrigation wells along the Oregon-California border, and that of the geothermal system near Klamath Falls. Groundwater produced by the deep irrigation wells along the Oregon-California border appears to be a mixture of eastern-basin groundwater and water with an evaporative isotopic signature. The component with an evaporative isotopic signature appears in some places to consist of infiltrated irrigation water. Chloride data suggest that much of the component with the evaporative isotopic signature may be coming from an adjacent subbasin. After accounting for the 18O shift common in geothermal waters, isotope data suggest that the geothermal groundwater in the upper Klamath Basin may emanate from the eastern basin uplands. Findings demonstrate that stable isotope and chloride data can illuminate certain details of a regional groundwater flow system in a complex geologic setting where other hydrologic data are ambiguous. ?? 2007 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jhydrol.2006.12.008","issn":"00221694","usgsCitation":"Palmer, P., Gannett, M.W., and Hinkle, S., 2007, Isotopic characterization of three groundwater recharge sources and inferences for selected aquifers in the upper Klamath Basin of Oregon and California, USA: Journal of Hydrology, v. 336, no. 1-2, p. 17-29, https://doi.org/10.1016/j.jhydrol.2006.12.008.","startPage":"17","endPage":"29","numberOfPages":"13","costCenters":[],"links":[{"id":212943,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2006.12.008"},{"id":240512,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"336","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3f9be4b0c8380cd64661","contributors":{"authors":[{"text":"Palmer, P.C.","contributorId":86972,"corporation":false,"usgs":true,"family":"Palmer","given":"P.C.","email":"","affiliations":[],"preferred":false,"id":423937,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gannett, M. W.","contributorId":75569,"corporation":false,"usgs":true,"family":"Gannett","given":"M.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":423936,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hinkle, S.R.","contributorId":74778,"corporation":false,"usgs":true,"family":"Hinkle","given":"S.R.","email":"","affiliations":[],"preferred":false,"id":423935,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70029710,"text":"70029710 - 2007 - Evidence for terrigenic SF6 in groundwater from basaltic aquifers, Jeju Island, Korea: Implications for groundwater dating","interactions":[],"lastModifiedDate":"2018-10-16T09:55:18","indexId":"70029710","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Evidence for terrigenic SF6 in groundwater from basaltic aquifers, Jeju Island, Korea: Implications for groundwater dating","docAbstract":"Measurements of the concentrations of dichlorodifluoromethane (CFC-12), tritium (3H), and sulfur hexafluoride (SF6) in groundwater from basaltic aquifers in Jeju Island, Korea, demonstrate a terrigenic source of SF6. Using a lumped-parameter dispersion model, groundwater was identified as young water (<15 years), old water with negligible CFC-12 and 3H, and binary mixtures of the two. Model calculations using dispersion models and binary mixing based on 3H and CFC-12 concentrations demonstrate a non-atmospheric excess of SF6 relative to CFC-12 and 3H concentrations for more than half of the samples. The non-atmospheric excess SF6 may have originated from terrigenic sources in relict volcanic fluids, which could have acquired SF6 from granites and basement rocks of the island during volcanic activity. Local excess anthropogenic sources of SF6 are unlikely. The SF6 age is biased young relative to the CFC-12 age, typically up to 20 years and as high as 30 years. This age bias is more pronounced in samples of groundwater older than 15 years. The presence of terrigenic SF6 can affect the entire dating range for groundwater in mixtures that contain a fraction of old water.
","language":"English","publisher":"Elsevier","doi":"10.1016/j.jhydrol.2007.03.011","issn":"00221694","usgsCitation":"Koh, D., Plummer, N., Busenberg, E., and Kim, Y., 2007, Evidence for terrigenic SF6 in groundwater from basaltic aquifers, Jeju Island, Korea: Implications for groundwater dating: Journal of Hydrology, v. 339, no. 1-2, p. 93-104, https://doi.org/10.1016/j.jhydrol.2007.03.011.","productDescription":"12 p.","startPage":"93","endPage":"104","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":240576,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212998,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2007.03.011"}],"country":"South Korea","otherGeospatial":"Jeju Island","volume":"339","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0d54e4b0c8380cd52f5b","contributors":{"authors":[{"text":"Koh, Dong-Chan","contributorId":167733,"corporation":false,"usgs":false,"family":"Koh","given":"Dong-Chan","email":"","affiliations":[{"id":24820,"text":"Korea Institute of Geoscience and Mineral Resources","active":true,"usgs":false}],"preferred":false,"id":423955,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Plummer, Niel 0000-0002-4020-1013 nplummer@usgs.gov","orcid":"https://orcid.org/0000-0002-4020-1013","contributorId":190100,"corporation":false,"usgs":true,"family":"Plummer","given":"Niel","email":"nplummer@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":423954,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Busenberg, Eurybiades ebusenbe@usgs.gov","contributorId":2271,"corporation":false,"usgs":true,"family":"Busenberg","given":"Eurybiades","email":"ebusenbe@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":423953,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Kim, Yongje","contributorId":203716,"corporation":false,"usgs":false,"family":"Kim","given":"Yongje","email":"","affiliations":[],"preferred":false,"id":423952,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70029712,"text":"70029712 - 2007 - Nitrate dynamics within the Pajaro River, a nutrient-rich, losing stream","interactions":[],"lastModifiedDate":"2023-08-09T11:21:29.048891","indexId":"70029712","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2564,"text":"Journal of the North American Benthological Society","onlineIssn":"1937-237X","printIssn":"0887-3593","active":true,"publicationSubtype":{"id":10}},"title":"Nitrate dynamics within the Pajaro River, a nutrient-rich, losing stream","docAbstract":"The major ion chemistry of water from an 11.42-km reach of the Pajaro River, a losing stream in central coastal California, shows a consistent pattern of higher concentrations during the 2nd (dry) half of the water year. Most solutes are conserved during flow along the reach, but [NO3−] decreases by ~30% and is accompanied by net loss of channel discharge and extensive surface–subsurface exchange. The corresponding net NO3− uptake length is 37 ± 13 km (42 ± 12 km when normalized to the conservative solute Cl−), and the areal NO3− uptake rate is 0.5 μmol m−2 s−1. The observed reduction in [NO3−] along the reach results from one or more internal sinks, not dilution by ground water, hill-slope water, or other water inputs. Observed reductions in [NO3−] and channel discharge along the experimental reach result in a net loss of 200–400 kg/d of NO3−-N, ~50% of the input load. High-resolution (temporal and spatial) sampling indicates that most of the NO3− loss occurs along the lower part of the reach, where there is the greatest seepage loss and surface–subsurface exchange of water. Stable isotopes of NO3−, total dissolved P concentrations, and streambed chemical profiles suggest that denitrification is the most significant NO3− sink along the reach. Denitrification efficiency, as expressed through downstream enrichment in 15N-NO3−, varies considerably during the water year. When discharge is greater (typically earlier in the water year), denitrification is least efficient and downstream enrichment in 15N-NO3− is greatest. When discharge is lower, denitrification in the streambed appears to occur with greater efficiency, resulting in lower downstream enrichment in 15N-NO3−.
","language":"English","publisher":"University of Chicago Press","doi":"10.1899/0887-3593(2007)26[191:NDWTPR]2.0.CO;2","issn":"08873593","usgsCitation":"Ruehl, C., Fisher, A., Los, H.M., Wankel, S.D., Wheat, C., Kendall, C., Hatch, C., and Shennan, C., 2007, Nitrate dynamics within the Pajaro River, a nutrient-rich, losing stream: Journal of the North American Benthological Society, v. 26, no. 2, p. 191-206, https://doi.org/10.1899/0887-3593(2007)26[191:NDWTPR]2.0.CO;2.","productDescription":"16 p.","startPage":"191","endPage":"206","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":240609,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Pajaro River","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"coordinates\": [\n [\n [\n -122.98626284071494,\n 37.37078225360888\n ],\n [\n -122.98626284071494,\n 35.694360455569424\n ],\n [\n -119.69177791118913,\n 35.694360455569424\n ],\n [\n -119.69177791118913,\n 37.37078225360888\n ],\n [\n -122.98626284071494,\n 37.37078225360888\n ]\n ]\n ],\n \"type\": \"Polygon\"\n }\n }\n ]\n}","volume":"26","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a669ee4b0c8380cd72ea2","contributors":{"authors":[{"text":"Ruehl, C.R.","contributorId":30826,"corporation":false,"usgs":true,"family":"Ruehl","given":"C.R.","affiliations":[],"preferred":false,"id":423964,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fisher, A.T.","contributorId":51528,"corporation":false,"usgs":true,"family":"Fisher","given":"A.T.","email":"","affiliations":[],"preferred":false,"id":423966,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Los, Huertos M.","contributorId":92872,"corporation":false,"usgs":true,"family":"Los","given":"Huertos","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":423969,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wankel, Scott D.","contributorId":98076,"corporation":false,"usgs":true,"family":"Wankel","given":"Scott","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":423970,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Wheat, C.G.","contributorId":59249,"corporation":false,"usgs":true,"family":"Wheat","given":"C.G.","email":"","affiliations":[],"preferred":false,"id":423967,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"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":423965,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Hatch, C.E.","contributorId":11402,"corporation":false,"usgs":true,"family":"Hatch","given":"C.E.","email":"","affiliations":[],"preferred":false,"id":423963,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Shennan, C.","contributorId":65671,"corporation":false,"usgs":true,"family":"Shennan","given":"C.","email":"","affiliations":[],"preferred":false,"id":423968,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ,{"id":70029714,"text":"70029714 - 2007 - Correcting acoustic Doppler current profiler discharge measurement bias from moving-bed conditions without global positioning during the 2004 Glen Canyon Dam controlled flood on the Colorado River","interactions":[],"lastModifiedDate":"2012-03-12T17:21:38","indexId":"70029714","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2622,"text":"Limnology and Oceanography: Methods","active":true,"publicationSubtype":{"id":10}},"title":"Correcting acoustic Doppler current profiler discharge measurement bias from moving-bed conditions without global positioning during the 2004 Glen Canyon Dam controlled flood on the Colorado River","docAbstract":"Discharge measurements were made by acoustic Doppler current profiler at two locations on the Colorado River during the 2004 controlled flood from Glen Canyon Dam, Arizona. Measurement hardware and software have constantly improved from the 1980s such that discharge measurements by acoustic profiling instruments are now routinely made over a wide range of hydrologic conditions. However, measurements made with instruments deployed from moving boats require reliable boat velocity data for accurate measurements of discharge. This is normally accomplished by using special acoustic bottom track pings that sense instrument motion over bottom. While this method is suitable for most conditions, high current flows that produce downstream bed sediment movement create a condition known as moving bed that will bias velocities and discharge to lower than actual values. When this situation exists, one solution is to determine boat velocity with satellite positioning information. Another solution is to use a lower frequency instrument. Discharge measurements made during the 2004 Glen Canyon controlled flood were subject to moving-bed conditions and frequent loss of bottom track. Due to site conditions and equipment availability, the measurements were conducted without benefit of external positioning information or lower frequency instruments. This paper documents and evaluates several techniques used to correct the resulting underestimated discharge measurements. One technique produces discharge values in good agreement with estimates from numerical model and measured hydrographs during the flood. ?? 2007, by the American Society of Limnology and Oceanography, Inc.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Limnology and Oceanography: Methods","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","issn":"15415856","usgsCitation":"Gartner, J.W., and Ganju, N., 2007, Correcting acoustic Doppler current profiler discharge measurement bias from moving-bed conditions without global positioning during the 2004 Glen Canyon Dam controlled flood on the Colorado River: Limnology and Oceanography: Methods, v. 5, no. JUN, p. 156-162.","startPage":"156","endPage":"162","numberOfPages":"7","costCenters":[],"links":[{"id":240641,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"5","issue":"JUN","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059fc1ee4b0c8380cd4e11d","contributors":{"authors":[{"text":"Gartner, J. W.","contributorId":81903,"corporation":false,"usgs":false,"family":"Gartner","given":"J.","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":423973,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ganju, N. K. 0000-0002-1096-0465","orcid":"https://orcid.org/0000-0002-1096-0465","contributorId":64782,"corporation":false,"usgs":true,"family":"Ganju","given":"N. K.","affiliations":[],"preferred":false,"id":423972,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70029723,"text":"70029723 - 2007 - Flux and age of dissolved organic carbon exported to the Arctic Ocean: A carbon isotopic study of the five largest arctic rivers","interactions":[],"lastModifiedDate":"2018-01-31T10:46:19","indexId":"70029723","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1836,"text":"Global Biogeochemical Cycles","active":true,"publicationSubtype":{"id":10}},"title":"Flux and age of dissolved organic carbon exported to the Arctic Ocean: A carbon isotopic study of the five largest arctic rivers","docAbstract":"The export and Δ14C-age of dissolved organic carbon (DOC) was determined for the Yenisey, Lena, Ob', Mackenzie, and Yukon rivers for 2004–2005. Concentrations of DOC elevate significantly with increasing discharge in these rivers, causing approximately 60% of the annual export to occur during a 2-month period following spring ice breakup. We present a total annual flux from the five rivers of ∼16 teragrams (Tg), and conservatively estimate that the total input of DOC to the Arctic Ocean is 25–36 Tg, which is ∼5–20% greater than previous fluxes. These fluxes are also ∼2.5× greater than temperate rivers with similar watershed sizes and water discharge. Δ14C-DOC shows a clear relationship with hydrology. A small pool of DOC slightly depleted in Δ14C is exported with base flow. The large pool exported with spring thaw is enriched in Δ14C with respect to current-day atmospheric Δ14C-CO2 values. A simple model predicts that ∼50% of DOC exported during the arctic spring thaw is 1–5 years old, ∼25% is 6–10 years in age, and 15% is 11–20 years old. The dominant spring melt period, a historically undersampled period, exports a large amount of young and presumably semilabile DOC to the Arctic Ocean.
","language":"English","publisher":"AGU","doi":"10.1029/2007GB002934","issn":"08866236","usgsCitation":"Raymond, P., McClelland, J., Holmes, R., Zhulidov, A., Mull, K., Peterson, B.J., Striegl, R.G., Aiken, G., and Gurtovaya, T., 2007, Flux and age of dissolved organic carbon exported to the Arctic Ocean: A carbon isotopic study of the five largest arctic rivers: Global Biogeochemical Cycles, v. 21, no. 4, https://doi.org/10.1029/2007GB002934.","costCenters":[],"links":[{"id":240235,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212708,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2007GB002934"}],"volume":"21","issue":"4","noUsgsAuthors":false,"publicationDate":"2007-11-02","publicationStatus":"PW","scienceBaseUri":"505a12a7e4b0c8380cd543b0","contributors":{"authors":[{"text":"Raymond, P.A.","contributorId":62013,"corporation":false,"usgs":true,"family":"Raymond","given":"P.A.","affiliations":[],"preferred":false,"id":424010,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McClelland, J.W.","contributorId":62015,"corporation":false,"usgs":true,"family":"McClelland","given":"J.W.","email":"","affiliations":[],"preferred":false,"id":424011,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Holmes, R.M.","contributorId":66485,"corporation":false,"usgs":true,"family":"Holmes","given":"R.M.","email":"","affiliations":[],"preferred":false,"id":424012,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Zhulidov, A.V.","contributorId":60020,"corporation":false,"usgs":true,"family":"Zhulidov","given":"A.V.","email":"","affiliations":[],"preferred":false,"id":424009,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Mull, K.","contributorId":17045,"corporation":false,"usgs":true,"family":"Mull","given":"K.","email":"","affiliations":[],"preferred":false,"id":424006,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Peterson, B. J.","contributorId":53749,"corporation":false,"usgs":false,"family":"Peterson","given":"B.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":424008,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Striegl, Robert G. 0000-0002-8251-4659 rstriegl@usgs.gov","orcid":"https://orcid.org/0000-0002-8251-4659","contributorId":1630,"corporation":false,"usgs":true,"family":"Striegl","given":"Robert","email":"rstriegl@usgs.gov","middleInitial":"G.","affiliations":[{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true},{"id":36183,"text":"Hydro-Ecological Interactions Branch","active":true,"usgs":true},{"id":200,"text":"Coop Res Unit Seattle","active":true,"usgs":true},{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":false,"id":424013,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Aiken, G. R. 0000-0001-8454-0984","orcid":"https://orcid.org/0000-0001-8454-0984","contributorId":14452,"corporation":false,"usgs":true,"family":"Aiken","given":"G. R.","affiliations":[],"preferred":false,"id":424005,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Gurtovaya, T.Y.","contributorId":53604,"corporation":false,"usgs":true,"family":"Gurtovaya","given":"T.Y.","email":"","affiliations":[],"preferred":false,"id":424007,"contributorType":{"id":1,"text":"Authors"},"rank":9}]}} ,{"id":70029730,"text":"70029730 - 2007 - Phosphorus budgets in Everglades wetland ecosystems: The effects of hydrology and nutrient enrichment","interactions":[],"lastModifiedDate":"2012-03-12T17:21:06","indexId":"70029730","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3751,"text":"Wetlands Ecology and Management","active":true,"publicationSubtype":{"id":10}},"title":"Phosphorus budgets in Everglades wetland ecosystems: The effects of hydrology and nutrient enrichment","docAbstract":"The Florida Everglades is a naturally oligotrophic hydroscape that has experienced large changes in ecosystem structure and function as the result of increased anthropogenic phosphorus (P) loading and hydrologic changes. We present whole-ecosystem models of P cycling for Everglades wetlands with differing hydrology and P enrichment with the goal of synthesizing existing information into ecosystem P budgets. Budgets were developed for deeper water oligotrophic wet prairie/slough ('Slough'), shallower water oligotrophic Cladium jamaicense ('Cladium'), partially enriched C. jamaicense/Typha spp. mixture ('Cladium/Typha'), and enriched Typha spp. ('Typha') marshes. The majority of ecosystem P was stored in the soil in all four ecosystem types, with the flocculent detrital organic matter (floc) layer at the bottom of the water column storing the next largest proportion of ecosystem P pools. However, most P cycling involved ecosystem components in the water column (periphyton, floc, and consumers) in deeper water, oligotrophic Slough marsh. Fluxes of P associated with macrophytes were more important in the shallower water, oligotrophic Cladium marsh. The two oligotrophic ecosystem types had similar total ecosystem P stocks and cycling rates, and low rates of P cycling associated with soils. Phosphorus flux rates cannot be estimated for ecosystem components residing in the water column in Cladium/Typha or Typha marshes due to insufficient data. Enrichment caused a large increase in the importance of macrophytes to P cycling in Everglades wetlands. The flux of P from soil to the water column, via roots to live aboveground tissues to macrophyte detritus, increased from 0.03 and 0.2 g P m-2 yr-1 in oligotrophic Slough and Cladium marsh, respectively, to 1.1 g P m-2 yr -1 in partially enriched Cladium/Typha, and 1.6 g P m-2 yr-1 in enriched Typha marsh. This macrophyte translocation P flux represents a large source of internal eutrophication to surface waters in P-enriched areas of the Everglades. ?? 2007 Springer Science+Business Media, Inc.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Wetlands Ecology and Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s11273-006-9023-5","issn":"09234861","usgsCitation":"Noe, G., and Childers, D., 2007, Phosphorus budgets in Everglades wetland ecosystems: The effects of hydrology and nutrient enrichment: Wetlands Ecology and Management, v. 15, no. 3, p. 189-205, https://doi.org/10.1007/s11273-006-9023-5.","startPage":"189","endPage":"205","numberOfPages":"17","costCenters":[],"links":[{"id":212800,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s11273-006-9023-5"},{"id":240342,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"15","issue":"3","noUsgsAuthors":false,"publicationDate":"2007-01-16","publicationStatus":"PW","scienceBaseUri":"505a78b4e4b0c8380cd7876a","contributors":{"authors":[{"text":"Noe, G.B.","contributorId":66464,"corporation":false,"usgs":true,"family":"Noe","given":"G.B.","email":"","affiliations":[],"preferred":false,"id":424039,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Childers, D.L.","contributorId":44334,"corporation":false,"usgs":true,"family":"Childers","given":"D.L.","email":"","affiliations":[],"preferred":false,"id":424038,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70029731,"text":"70029731 - 2007 - Bedrock aquifers and population growth in the Denver Basin, Colorado, USA","interactions":[],"lastModifiedDate":"2018-04-10T11:05:50","indexId":"70029731","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1582,"text":"Episodes","active":true,"publicationSubtype":{"id":10}},"title":"Bedrock aquifers and population growth in the Denver Basin, Colorado, USA","docAbstract":"The Denver Basin bedrock aquifer system consists of Tertiary and Cretaceous age sedimentary rocks known as the Dawson, Denver, Arapahoe and Laramie-Fox Hills aquifers. The number of bedrock wells has increased from 12,000 in 1985 to over 33,700 in 2001 and the withdrawal of groundwater has caused water level declines in excess of 75 meters. Water level declines now range from 3 to 12 meters per year in the critical Arapahoe Aquifer. The groundwater supplies were once thought to be sufficient for 100 years but there is concern that they may be depleted in 10 to 15 years in areas on the west side of the basin. Groundwater is being mined from the aquifer system because the withdrawal through wells exceeds the rate of recharge. Increased groundwater withdrawal will cause further water level declines, increased costs to pump groundwater, and reduced yield from existing wells. In the Denver Basin, hydrologists have some capability to monitor declines in water levels for the Arapaho Aquifer, but generally have a limited ability to monitor water use. More complete and accurate water use data are needed to predict groundwater longevity for the Arapahoe Aquifer. The life of the Arapahoe Aquifer can be extended with artificial recharge using imported surface water, water reuse, restrictions on lawn watering, well permit restrictions and other conservation measures. Availability of groundwater may limit growth in the Denver Basin over the next 20 years unless residents are willing to pay for additional new sources of supply.","language":"English","publisher":"International Union of Geological Sciences","issn":"07053797","usgsCitation":"Moore, J., Raynolds, R., and Dechesne, M., 2007, Bedrock aquifers and population growth in the Denver Basin, Colorado, USA: Episodes, v. 30, no. 2, p. 115-118.","productDescription":"4 p.","startPage":"115","endPage":"118","numberOfPages":"4","costCenters":[],"links":[{"id":240343,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":265825,"type":{"id":15,"text":"Index Page"},"url":"https://www.episodes.org/journalArchive.do"}],"volume":"30","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f048e4b0c8380cd4a6bf","contributors":{"authors":[{"text":"Moore, J.E.","contributorId":34927,"corporation":false,"usgs":true,"family":"Moore","given":"J.E.","email":"","affiliations":[],"preferred":false,"id":424040,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Raynolds, R.G.","contributorId":39006,"corporation":false,"usgs":true,"family":"Raynolds","given":"R.G.","email":"","affiliations":[],"preferred":false,"id":424041,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dechesne, M.","contributorId":72207,"corporation":false,"usgs":true,"family":"Dechesne","given":"M.","affiliations":[],"preferred":false,"id":424042,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70029740,"text":"70029740 - 2007 - Formation of mixed Al-Fe colloidal sorbent and dissolved-colloidal partitioning of Cu and Zn in the Cement Creek - Animas River Confluence, Silverton, Colorado","interactions":[],"lastModifiedDate":"2023-08-02T11:33:46.512511","indexId":"70029740","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Formation of mixed Al-Fe colloidal sorbent and dissolved-colloidal partitioning of Cu and Zn in the Cement Creek - Animas River Confluence, Silverton, Colorado","docAbstract":"Transport and chemical transformations of dissolved and colloidal Al, Fe, Cu and Zn were studied by detailed sampling in the mixing zone downstream from the confluence of Cement Creek (pH 4.1) with the Animas River (pH 7.6). Complete mixing resulted in circumneutral pH in the downstream reach of the 1300 m study area. All four metals were transported through this mixing zone without significant losses to the streambed, and they exhibited transformations from dissolved to colloidal forms to varying degrees during the mixing process. Nearly all of the Al formed colloidal hydrous Al oxides (HAO) as pH increased (4.8–6.5), whereas colloidal hydrous Fe oxides (HFO) were supplied by Cement Creek as well as formed in the mixing zone primarily at higher pH (>6.5). The short travel time through the mixing zone (approx. 40 min) and pH limited the formation of HFO from dissolved Fe2+ supplied by Cement Creek. Although the proportions of HAO and HFO varied as the streams mixed, the colloidal sorbent typically was enriched in HAO relative to HFO by a factor of 1.5–2.1 (by mole) in the pH range where dissolved-to-colloidal partitioning of Cu and Zn was observed. Model simulations of sorption by HFO (alone) greatly underestimated the dissolved-to-colloidal partitioning of Zn. Previous studies have shown that HAO–HFO mixtures can sorb greater amounts of Zn than HFO alone, but the high Zn-to-sorbent ratio in this mixing zone could also account for greater partitioning. In contrast to Zn, comparisons with model simulations did not show that Cu sorption was greater than that for HFO alone, and also indicated that sorption was possibly less than what would be expected for a non-interactive mixture of these two sorbents. These field results for Cu, however, might be influenced by (organic) complexation or other factors in this natural system. Laboratory mixing experiments using natural source waters (upstream of the confluence) showed that the presence of HFO in the mixed sorbent resulted in greater Cu partitioning than for HAO alone, and that the effect was greater with increasing (mole fraction) HFO. This was consistent with field results that showed greater Cu sorption when additional HFO was formed in the downstream reach of the mixing zone. Further research is needed to identify the significance of surface-related mechanisms specific to HAO–HFO mixtures that could affect the partitioning of Cu in natural systems.
Populations of chemotactic bacteria are able to sense and respond to chemical gradients in their surroundings and direct their migration toward increasing concentrations of chemicals that they perceive to be beneficial to their survival. It has been suggested that this phenomenon may facilitate bioremediation processes by bringing bacteria into closer proximity to the chemical contaminants that they degrade. To determine the significance of chemotaxis in these processes it is necessary to quantify the magnitude of the response and compare it to other groundwater processes that affect the fate and transport of bacteria. We present a systematic approach toward quantifying the chemotactic response of bacteria in laboratory scale experiments by starting with simple, well-defined systems and gradually increasing their complexity. Swimming properties of individual cells were assessed from trajectories recorded by a tracking microscope. These properties were used to calculate motility and chemotaxis coefficients of bacterial populations in bulk aqueous media which were compared to experimental results of diffusion studies. Then effective values of motility and chemotaxis coefficients in single pores, pore networks and packed columns were analyzed. These were used to estimate the magnitude of the chemotactic response in porous media and to compare with dispersion coefficients reported in the field. This represents a compilation of many studies over a number of years. While there are certainly limitations with this approach for ultimately quantifying motility and chemotaxis in granular aquifer media, it does provide insight into what order of magnitude responses are possible and which characteristics of the bacteria and media are expected to be important.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Advances in Water Resources","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/j.advwatres.2006.05.019","issn":"03091708","usgsCitation":"Ford, R., and Harvey, R.W., 2007, Role of chemotaxis in the transport of bacteria through saturated porous media: Advances in Water Resources, v. 30, no. 6-7, p. 1608-1617, https://doi.org/10.1016/j.advwatres.2006.05.019.","productDescription":"10 p.","startPage":"1608","endPage":"1617","numberOfPages":"10","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":213030,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.advwatres.2006.05.019"},{"id":240610,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"30","issue":"6-7","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aae49e4b0c8380cd87072","contributors":{"authors":[{"text":"Ford, R.M.","contributorId":95689,"corporation":false,"usgs":true,"family":"Ford","given":"R.M.","email":"","affiliations":[],"preferred":false,"id":424118,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Harvey, Ronald W. 0000-0002-2791-8503 rwharvey@usgs.gov","orcid":"https://orcid.org/0000-0002-2791-8503","contributorId":564,"corporation":false,"usgs":true,"family":"Harvey","given":"Ronald","email":"rwharvey@usgs.gov","middleInitial":"W.","affiliations":[{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":true,"id":424117,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70029774,"text":"70029774 - 2007 - The science and practice of environmental flows and the role of hydrogeologists","interactions":[],"lastModifiedDate":"2012-03-12T17:21:06","indexId":"70029774","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"The science and practice of environmental flows and the role of hydrogeologists","docAbstract":"Conflicts between ecosystems and human needs for fresh water are increasing. The purpose of this paper is to raise awareness in the hydrogeologic community of environmental flows (EFs) and to address the major challenges involved in their protection. Ground water is a key component of EFs, and therefore hydrogeologists are called upon to get involved in the ongoing debates about maintaining healthy riverine ecosystems. Promising opportunities for achieving EFs in both underallocated and overallocated basins as well as new methods for protecting fresh water ecosystems developed in different countries are outlined. EF protection measures include private water trusts, \"upside-down instream flow water rights,\" the \"public trust\" doctrine, and water markets, among other measures. A number of knowledge gaps are identified, to which hydrogeologists could contribute, such as our rudimentary knowledge about ground water-dependent ecosystems, aspects of stream-aquifer interactions, and the impacts of land-use changes. The values that society places on the different uses of water ultimately determine where the water is allocated. EF requirements can be legitimately recognized and addressed by basing the environmental needs of hydrologic systems on robust science, focusing on increasing the productivity of water use, engaging society in understanding the benefits and costs of decisions that affect ecosystems, and taking advantage of various opportunities for achieving EF goals. ?? 2007 National Ground Water Association.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ground Water","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1745-6584.2007.00322.x","issn":"0017467X","usgsCitation":"Sophocleous, M., 2007, The science and practice of environmental flows and the role of hydrogeologists: Ground Water, v. 45, no. 4, p. 393-401, https://doi.org/10.1111/j.1745-6584.2007.00322.x.","startPage":"393","endPage":"401","numberOfPages":"9","costCenters":[],"links":[{"id":212834,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1745-6584.2007.00322.x"},{"id":240383,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"45","issue":"4","noUsgsAuthors":false,"publicationDate":"2007-05-04","publicationStatus":"PW","scienceBaseUri":"505bafb6e4b08c986b3249c4","contributors":{"authors":[{"text":"Sophocleous, M.","contributorId":13373,"corporation":false,"usgs":true,"family":"Sophocleous","given":"M.","email":"","affiliations":[],"preferred":false,"id":424236,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}} ,{"id":70029792,"text":"70029792 - 2007 - Origin of halite brine in the Onondaga Trough near Syracuse, New York State, USA: Modeling geochemistry and variable-density flow","interactions":[],"lastModifiedDate":"2018-10-17T11:35:25","indexId":"70029792","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1923,"text":"Hydrogeology Journal","active":true,"publicationSubtype":{"id":10}},"title":"Origin of halite brine in the Onondaga Trough near Syracuse, New York State, USA: Modeling geochemistry and variable-density flow","docAbstract":"Halite brine (saturation ranging from 45 to 80%) lies within glacial sediments that fill the Onondaga Trough, a bedrock valley deepened by Pleistocene glaciation near Syracuse, New York State, USA. The most concentrated brine occupies the northern end of the trough, about 10 km downgradient of the northern limit of halite beds in the Silurian Salina Group, the assumed source of salt. The chemical composition of the brine and its radiocarbon age suggest that the brine originally formed about 16,700 years ago through dissolution of halite by glacial melt water and later mixed with saline bedrock water. Two hypotheses regarding the formation of the brine pool were tested through variable-density flow simulations using SEAWAT. Simulation results supported the first hypothesis that the brine pool was derived from a source in the glacial sediments and then migrated to its current position, where it has persisted for over 16,000 years. A second hypothesis that the brine pool formed through steady accumulation of brine from upward flow of a source in the underlying bedrock was not supported by simulation results, because the simulated age distribution was much younger than the age estimated from geochemical modeling.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrogeology Journal","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Springer-Verlag","doi":"10.1007/s10040-007-0186-9","issn":"14312174","usgsCitation":"Yager, R.M., Kappel, W.M., and Plummer, N., 2007, Origin of halite brine in the Onondaga Trough near Syracuse, New York State, USA: Modeling geochemistry and variable-density flow: Hydrogeology Journal, v. 15, no. 7, p. 1321-1339, https://doi.org/10.1007/s10040-007-0186-9.","productDescription":"19 p.","startPage":"1321","endPage":"1339","numberOfPages":"19","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":477062,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://zenodo.org/record/1232767","text":"External Repository"},{"id":240677,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213088,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10040-007-0186-9"}],"country":"United States","state":"New York","city":"Syracuse","otherGeospatial":"Onondaga Trough","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -76.33333333333333,42.75 ], [ -76.33333333333333,43.166666666666664 ], [ -76.08333333333333,43.166666666666664 ], [ -76.08333333333333,42.75 ], [ -76.33333333333333,42.75 ] ] ] } } ] }","volume":"15","issue":"7","noUsgsAuthors":false,"publicationDate":"2007-05-24","publicationStatus":"PW","scienceBaseUri":"505a70d7e4b0c8380cd762a8","contributors":{"authors":[{"text":"Yager, Richard M. 0000-0001-7725-1148 ryager@usgs.gov","orcid":"https://orcid.org/0000-0001-7725-1148","contributorId":950,"corporation":false,"usgs":true,"family":"Yager","given":"Richard","email":"ryager@usgs.gov","middleInitial":"M.","affiliations":[{"id":614,"text":"Virginia Water Science Center","active":true,"usgs":true},{"id":474,"text":"New York Water Science Center","active":true,"usgs":true}],"preferred":true,"id":424357,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kappel, William M. 0000-0002-2382-9757 wkappel@usgs.gov","orcid":"https://orcid.org/0000-0002-2382-9757","contributorId":1074,"corporation":false,"usgs":true,"family":"Kappel","given":"William","email":"wkappel@usgs.gov","middleInitial":"M.","affiliations":[{"id":474,"text":"New York Water Science Center","active":true,"usgs":true}],"preferred":true,"id":424358,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Plummer, Niel 0000-0002-4020-1013 nplummer@usgs.gov","orcid":"https://orcid.org/0000-0002-4020-1013","contributorId":190100,"corporation":false,"usgs":true,"family":"Plummer","given":"Niel","email":"nplummer@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":424359,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70029795,"text":"70029795 - 2007 - Altered stream-flow regimes and invasive plant species: The Tamarix case","interactions":[],"lastModifiedDate":"2012-03-12T17:21:08","indexId":"70029795","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1839,"text":"Global Ecology and Biogeography","active":true,"publicationSubtype":{"id":10}},"title":"Altered stream-flow regimes and invasive plant species: The Tamarix case","docAbstract":"Aim: To test the hypothesis that anthropogenic alteration of stream-flow regimes is a key driver of compositional shifts from native to introduced riparian plant species. Location: The arid south-western United States; 24 river reaches in the Gila and Lower Colorado drainage basins of Arizona. Methods: We compared the abundance of three dominant woody riparian taxa (native Populus fremontii and Salix gooddingii, and introduced Tamarix) between river reaches that varied in stream-flow permanence (perennial vs. intermittent), presence or absence of an upstream flow-regulating dam, and presence or absence of municipal effluent as a stream water source. Results: Populus and Salix were the dominant pioneer trees along the reaches with perennial flow and a natural flood regime. In contrast, Tamarix had high abundance (patch area and basal area) along reaches with intermittent stream flows (caused by natural and cultural factors), as well as those with dam-regulated flows. Main conclusions: Stream-flow regimes are strong determinants of riparian vegetation structure, and hydrological alterations can drive dominance shifts to introduced species that have an adaptive suite of traits. Deep alluvial groundwater on intermittent rivers favours the deep-rooted, stress-adapted Tamarix over the shallower-rooted and more competitive Populus and Salix. On flow-regulated rivers, shifts in flood timing favour the reproductively opportunistic Tamarix over Populus and Salix, both of which have narrow germination windows. The prevailing hydrological conditions thus favour a new dominant pioneer species in the riparian corridors of the American Southwest. These results reaffirm the importance of reinstating stream-flow regimes (inclusive of groundwater flows) for re-establishing the native pioneer trees as the dominant forest type. ?? 2007 The Authors Journal compilation ?? 2007 Blackwell Publishing Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Global Ecology and Biogeography","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1466-8238.2007.00297.x","issn":"1466822X","usgsCitation":"Stromberg, J., Lite, S., Marler, R., Paradzick, C., Shafroth, P., Shorrock, D., White, J.M., and White, M., 2007, Altered stream-flow regimes and invasive plant species: The Tamarix case: Global Ecology and Biogeography, v. 16, no. 3, p. 381-393, https://doi.org/10.1111/j.1466-8238.2007.00297.x.","startPage":"381","endPage":"393","numberOfPages":"13","costCenters":[],"links":[{"id":212653,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1466-8238.2007.00297.x"},{"id":240173,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"16","issue":"3","noUsgsAuthors":false,"publicationDate":"2007-01-18","publicationStatus":"PW","scienceBaseUri":"5059e97be4b0c8380cd482ec","contributors":{"authors":[{"text":"Stromberg, J.C.","contributorId":81455,"corporation":false,"usgs":true,"family":"Stromberg","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":424376,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Lite, S.J.","contributorId":35535,"corporation":false,"usgs":true,"family":"Lite","given":"S.J.","email":"","affiliations":[],"preferred":false,"id":424372,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Marler, R.","contributorId":13440,"corporation":false,"usgs":true,"family":"Marler","given":"R.","email":"","affiliations":[],"preferred":false,"id":424369,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Paradzick, C.","contributorId":17426,"corporation":false,"usgs":true,"family":"Paradzick","given":"C.","affiliations":[],"preferred":false,"id":424371,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Shafroth, P.B.","contributorId":65041,"corporation":false,"usgs":true,"family":"Shafroth","given":"P.B.","email":"","affiliations":[],"preferred":false,"id":424375,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Shorrock, D.","contributorId":58465,"corporation":false,"usgs":true,"family":"Shorrock","given":"D.","email":"","affiliations":[],"preferred":false,"id":424374,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"White, J. M.","contributorId":40268,"corporation":false,"usgs":true,"family":"White","given":"J.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":424373,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"White, M.S.","contributorId":14199,"corporation":false,"usgs":true,"family":"White","given":"M.S.","email":"","affiliations":[],"preferred":false,"id":424370,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}} ]}