{"pageNumber":"218","pageRowStart":"5425","pageSize":"25","recordCount":16458,"records":[{"id":70032525,"text":"70032525 - 2009 - Two statistics for evaluating parameter identifiability and error reduction","interactions":[],"lastModifiedDate":"2014-06-02T11:06:13","indexId":"70032525","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Two statistics for evaluating parameter identifiability and error reduction","docAbstract":"Two statistics are presented that can be used to rank input parameters utilized by a model in terms of their relative identifiability based on a given or possible future calibration dataset. Identifiability is defined here as the capability of model calibration to constrain parameters used by a model. Both statistics require that the sensitivity of each model parameter be calculated for each model output for which there are actual or presumed field measurements. Singular value decomposition (SVD) of the weighted sensitivity matrix is then undertaken to quantify the relation between the parameters and observations that, in turn, allows selection of calibration solution and null spaces spanned by unit orthogonal vectors. The first statistic presented, \"parameter identifiability\", is quantitatively defined as the direction cosine between a parameter and its projection onto the calibration solution space. This varies between zero and one, with zero indicating complete non-identifiability and one indicating complete identifiability. The second statistic, \"relative error reduction\", indicates the extent to which the calibration process reduces error in estimation of a parameter from its pre-calibration level where its value must be assigned purely on the basis of prior expert knowledge. This is more sophisticated than identifiability, in that it takes greater account of the noise associated with the calibration dataset. Like identifiability, it has a maximum value of one (which can only be achieved if there is no measurement noise). Conceptually it can fall to zero; and even below zero if a calibration problem is poorly posed. An example, based on a coupled groundwater/surface-water model, is included that demonstrates the utility of the statistics. ?? 2009 Elsevier B.V.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jhydrol.2008.12.018","issn":"00221","usgsCitation":"Doherty, J., and Hunt, R.J., 2009, Two statistics for evaluating parameter identifiability and error reduction: Journal of Hydrology, v. 366, no. 1-4, p. 119-127, https://doi.org/10.1016/j.jhydrol.2008.12.018.","startPage":"119","endPage":"127","numberOfPages":"9","costCenters":[],"links":[{"id":213886,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2008.12.018"},{"id":241553,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"366","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bb989e4b08c986b327c4b","contributors":{"authors":[{"text":"Doherty, John","contributorId":43843,"corporation":false,"usgs":true,"family":"Doherty","given":"John","affiliations":[],"preferred":false,"id":436637,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Hunt, Randall J. 0000-0001-6465-9304 rjhunt@usgs.gov","orcid":"https://orcid.org/0000-0001-6465-9304","contributorId":1129,"corporation":false,"usgs":true,"family":"Hunt","given":"Randall","email":"rjhunt@usgs.gov","middleInitial":"J.","affiliations":[{"id":677,"text":"Wisconsin Water Science Center","active":true,"usgs":true}],"preferred":true,"id":436636,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70032524,"text":"70032524 - 2009 - Shallow water processes govern system-wide phytoplankton bloom dynamics: A modeling study","interactions":[],"lastModifiedDate":"2018-10-08T09:05:19","indexId":"70032524","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2381,"text":"Journal of Marine Systems","active":true,"publicationSubtype":{"id":10}},"title":"Shallow water processes govern system-wide phytoplankton bloom dynamics: A modeling study","docAbstract":"<p><span>A pseudo-two-dimensional numerical model of estuarine phytoplankton growth and consumption, vertical turbulent mixing, and idealized cross-estuary transport was developed and applied to South San Francisco Bay. This estuary has two bathymetrically distinct habitat types (deep channel, shallow shoal) and associated differences in local net rates of phytoplankton growth and consumption, as well as differences in the water column's tendency to stratify. Because many physical and biological time scales relevant to algal population dynamics decrease with decreasing depth, process rates can be especially fast in the shallow water. We used the model to explore the potential significance of hydrodynamic connectivity between a channel and shoal and whether lateral transport can allow physical or biological processes (e.g. stratification, benthic grazing, light attenuation) in one sub-region to control phytoplankton biomass and bloom development in the adjacent sub-region. Model results for South San Francisco Bay suggest that lateral transport from a productive shoal can result in phytoplankton biomass accumulation in an adjacent deep, unproductive channel. The model further suggests that turbidity and benthic grazing in the shoal can control the occurrence of a bloom system-wide; whereas, turbidity, benthic grazing, and vertical density stratification in the channel are likely to only control local bloom occurrence or modify system-wide bloom magnitude. Measurements from a related field program are generally consistent with model-derived conclusions.</span></p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.jmarsys.2008.07.011","issn":"09247","usgsCitation":"Lucas, L., Koseff, J.R., Monismith, S., and Thompson, J., 2009, Shallow water processes govern system-wide phytoplankton bloom dynamics: A modeling study: Journal of Marine Systems, v. 75, no. 1-2, p. 70-86, https://doi.org/10.1016/j.jmarsys.2008.07.011.","productDescription":"17 p.","startPage":"70","endPage":"86","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":241516,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213853,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jmarsys.2008.07.011"}],"volume":"75","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b8e46e4b08c986b318834","contributors":{"authors":[{"text":"Lucas, L.V.","contributorId":62777,"corporation":false,"usgs":true,"family":"Lucas","given":"L.V.","email":"","affiliations":[],"preferred":false,"id":436634,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Koseff, Jeffrey R.","contributorId":37915,"corporation":false,"usgs":false,"family":"Koseff","given":"Jeffrey","email":"","middleInitial":"R.","affiliations":[{"id":6986,"text":"Stanford University","active":true,"usgs":false}],"preferred":false,"id":436632,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Monismith, Stephen G.","contributorId":57228,"corporation":false,"usgs":true,"family":"Monismith","given":"Stephen G.","affiliations":[],"preferred":false,"id":436633,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Thompson, J.K.","contributorId":103300,"corporation":false,"usgs":true,"family":"Thompson","given":"J.K.","email":"","affiliations":[],"preferred":false,"id":436635,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70034391,"text":"70034391 - 2009 - Introduction to special section on impacts of land use change on water resources","interactions":[],"lastModifiedDate":"2018-10-03T10:46:28","indexId":"70034391","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3722,"text":"Water Resources Research","onlineIssn":"1944-7973","printIssn":"0043-1397","active":true,"publicationSubtype":{"id":10}},"title":"Introduction to special section on impacts of land use change on water resources","docAbstract":"<p><span>Changes in land use have potentially large impacts on water resources, yet quantifying these impacts remains among the more challenging problems in hydrology. Water, food, energy, and climate are linked through complex webs of direct and indirect effects and feedbacks. Land use is undergoing major changes due not only to pressures for more efficient food, feed, and fiber production to support growing populations but also due to policy shifts that are creating markets for biofuel and agricultural carbon sequestration. Hydrologic systems embody flows of water, solutes, sediments, and energy that vary even in the absence of human activity. Understanding land use impacts thus necessitates integrated scientific approaches. Field measurements, remote sensing, and modeling studies are shedding new light on the modes and mechanisms by which land use changes impact water resources. Such studies can help deconflate the interconnected influences of human actions and natural variations on the quantity and quality of soil water, surface water, and groundwater, past, present, and future.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2009WR007937","usgsCitation":"Stonestrom, D.A., Scanlon, B., and Zhang, L., 2009, Introduction to special section on impacts of land use change on water resources: Water Resources Research, v. 45, no. 7, Article W00A00; 3 p., https://doi.org/10.1029/2009WR007937.","productDescription":"Article W00A00; 3 p.","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":244753,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"45","issue":"7","noUsgsAuthors":false,"publicationDate":"2009-06-17","publicationStatus":"PW","scienceBaseUri":"505a3df2e4b0c8380cd63994","contributors":{"authors":[{"text":"Stonestrom, David A. 0000-0001-7883-3385 dastones@usgs.gov","orcid":"https://orcid.org/0000-0001-7883-3385","contributorId":2280,"corporation":false,"usgs":true,"family":"Stonestrom","given":"David","email":"dastones@usgs.gov","middleInitial":"A.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":445573,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Scanlon, Bridget R.","contributorId":74093,"corporation":false,"usgs":true,"family":"Scanlon","given":"Bridget R.","affiliations":[],"preferred":false,"id":445572,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Zhang, Lu","contributorId":105238,"corporation":false,"usgs":true,"family":"Zhang","given":"Lu","email":"","affiliations":[],"preferred":false,"id":445571,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70032486,"text":"70032486 - 2009 - Hydrograph separation for karst watersheds using a two-domain rainfall-discharge model","interactions":[],"lastModifiedDate":"2012-03-12T17:21:22","indexId":"70032486","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Hydrograph separation for karst watersheds using a two-domain rainfall-discharge model","docAbstract":"Highly parameterized, physically based models may be no more effective at simulating the relations between rainfall and outflow from karst watersheds than are simpler models. Here an antecedent rainfall and convolution model was used to separate a karst watershed hydrograph into two outflow components: one originating from focused recharge in conduits and one originating from slow flow in a porous annex system. In convolution, parameters of a complex system are lumped together in the impulse-response function (IRF), which describes the response of the system to an impulse of effective precipitation. Two parametric functions in superposition approximate the two-domain IRF. The outflow hydrograph can be separated into flow components by forward modeling with isolated IRF components, which provides an objective criterion for separation. As an example, the model was applied to a karst watershed in the Madison aquifer, South Dakota, USA. Simulation results indicate that this watershed is characterized by a flashy response to storms, with a peak response time of 1 day, but that 89% of the flow results from the slow-flow domain, with a peak response time of more than 1 year. This long response time may be the result of perched areas that store water above the main water table. Simulation results indicated that some aspects of the system are stationary but that nonlinearities also exist.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jhydrol.2008.11.001","issn":"00221","usgsCitation":"Long, A., 2009, Hydrograph separation for karst watersheds using a two-domain rainfall-discharge model: Journal of Hydrology, v. 364, no. 3-4, p. 249-256, https://doi.org/10.1016/j.jhydrol.2008.11.001.","startPage":"249","endPage":"256","numberOfPages":"8","costCenters":[],"links":[{"id":213819,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2008.11.001"},{"id":241479,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"364","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a34f6e4b0c8380cd5fb7b","contributors":{"authors":[{"text":"Long, Andrew J.","contributorId":80023,"corporation":false,"usgs":false,"family":"Long","given":"Andrew J.","affiliations":[],"preferred":false,"id":436424,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70034358,"text":"70034358 - 2009 - Linking hydraulic properties of fire-affected soils to infiltration and water repellency","interactions":[],"lastModifiedDate":"2012-03-12T17:21:46","indexId":"70034358","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Linking hydraulic properties of fire-affected soils to infiltration and water repellency","docAbstract":"Heat from wildfires can produce a two-layer system composed of extremely dry soil covered by a layer of ash, which when subjected to rainfall, may produce extreme floods. To understand the soil physics controlling runoff for these initial conditions, we used a small, portable disk infiltrometer to measure two hydraulic properties: (1) near-saturated hydraulic conductivity, Kf and (2) sorptivity, S(??i), as a function of initial soil moisture content, ??i, ranging from extremely dry conditions (??i &lt; 0.02 cm3 cm-3) to near saturation. In the field and in the laboratory replicate measurements were made of ash, reference soils, soils unaffected by fire, and fire-affected soils. Each has a different degrees of water repellency that influences Kf and S(??i). Values of Kf ranged from 4.5 ?? 10-3 to 53 ?? 10-3 cm s-1 for ash; from 0.93 ?? 10-3 to 130 ?? 10-3 cm s-1 for reference soils; and from 0.86 ?? 10-3 to 3.0 ?? 10-3 cm s-1, for soil unaffected by fire, which had the lowest values of Kf. Measurements indicated that S(??i) could be represented by an empirical non-linear function of ??i with a sorptivity maximum of 0.18-0.20 cm s-0.5, between 0.03 and 0.08 cm3 cm-3. This functional form differs from the monotonically decreasing non-linear functions often used to represent S(??i) for rainfall-runoff modeling. The sorptivity maximum may represent the combined effects of gravity, capillarity, and adsorption in a transitional domain corresponding to extremely dry soil, and moreover, it may explain the observed non-linear behavior, and the critical soil-moisture threshold of water repellent soils. Laboratory measurements of Kf and S(??i) are the first for ash and fire-affected soil, but additional measurements are needed of these hydraulic properties for in situ fire-affected soils. They provide insight into water repellency behavior and infiltration under extremely dry conditions. Most importantly, they indicate how existing rainfall-runoff models can be modified to accommodate a possible two-layer system in extremely dry conditions. These modified models can be used to predict floods from burned watersheds under these initial conditions.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jhydrol.2009.10.015","issn":"00221694","usgsCitation":"Moody, J.A., Kinner, D., and Ubeda, X., 2009, Linking hydraulic properties of fire-affected soils to infiltration and water repellency: Journal of Hydrology, v. 379, no. 3-4, p. 291-303, https://doi.org/10.1016/j.jhydrol.2009.10.015.","startPage":"291","endPage":"303","numberOfPages":"13","costCenters":[],"links":[{"id":244722,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":216827,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2009.10.015"}],"volume":"379","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a47d4e4b0c8380cd679e3","contributors":{"authors":[{"text":"Moody, J. A.","contributorId":32930,"corporation":false,"usgs":true,"family":"Moody","given":"J.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":445396,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kinner, D.A.","contributorId":99265,"corporation":false,"usgs":true,"family":"Kinner","given":"D.A.","email":"","affiliations":[],"preferred":false,"id":445397,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Ubeda, X.","contributorId":17847,"corporation":false,"usgs":true,"family":"Ubeda","given":"X.","email":"","affiliations":[],"preferred":false,"id":445395,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70034353,"text":"70034353 - 2009 - UZIG USGS research: Advances through interdisciplinary interaction","interactions":[],"lastModifiedDate":"2018-10-15T08:37:38","indexId":"70034353","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3674,"text":"Vadose Zone Journal","active":true,"publicationSubtype":{"id":10}},"title":"UZIG USGS research: Advances through interdisciplinary interaction","docAbstract":"<p>B<span>Because vadose zone research relates to diverse disciplines, applications, and modes of research, collaboration across traditional operational and topical divisions is especially likely to yield major advances in understanding. The Unsaturated Zone Interest Group (UZIG) is an informal organization sponsored by the USGS to encourage and support interdisciplinary collaboration in vadose or unsaturated zone hydrologic research across organizational boundaries. It includes both USGS and non-USGS scientists. Formed in 1987, the UZIG operates to promote communication, especially through periodic meetings with presentations, discussions, and field trips. The 10th meeting of the UZIG at Los Alamos, NM, in August 2007 was jointly sponsored by the USGS and Los Alamos National Laboratory. Presentations at this meeting served as the initial basis for selecting papers for this special section of&nbsp;</span><i>Vadose Zone Journal</i><span>, the purpose of which is to present noteworthy cutting-edge unsaturated zone research promoted by, facilitated by, or presented in connection with the UZIG.</span></p>","language":"English","publisher":"Soil Science Society of America","doi":"10.2136/vzj2008.0185","usgsCitation":"Nimmo, J., Andraski, B.J., and Rafael, M., 2009, UZIG USGS research: Advances through interdisciplinary interaction: Vadose Zone Journal, v. 8, no. 2, p. 411-413, https://doi.org/10.2136/vzj2008.0185.","productDescription":"3 p.","startPage":"411","endPage":"413","costCenters":[{"id":465,"text":"Nevada Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":244688,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"8","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbbf7e4b08c986b328937","contributors":{"authors":[{"text":"Nimmo, J. R. 0000-0001-8191-1727","orcid":"https://orcid.org/0000-0001-8191-1727","contributorId":58304,"corporation":false,"usgs":true,"family":"Nimmo","given":"J. R.","affiliations":[],"preferred":false,"id":445379,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Andraski, Brian J. 0000-0002-2086-0417 andraski@usgs.gov","orcid":"https://orcid.org/0000-0002-2086-0417","contributorId":168800,"corporation":false,"usgs":true,"family":"Andraski","given":"Brian","email":"andraski@usgs.gov","middleInitial":"J.","affiliations":[{"id":38175,"text":"Toxics Substances Hydrology Program","active":true,"usgs":true},{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true},{"id":465,"text":"Nevada Water Science Center","active":true,"usgs":true}],"preferred":false,"id":445380,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Rafael, M.-C.","contributorId":26546,"corporation":false,"usgs":true,"family":"Rafael","given":"M.-C.","email":"","affiliations":[],"preferred":false,"id":445378,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70034346,"text":"70034346 - 2009 - Mercury sources, distribution, and bioavailability in the North Pacific Ocean: Insights from data and models","interactions":[],"lastModifiedDate":"2018-10-05T10:15:40","indexId":"70034346","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Mercury sources, distribution, and bioavailability in the North Pacific Ocean: Insights from data and models","docAbstract":"<p><span>Fish harvested from the Pacific Ocean are a major contributor to human methylmercury (MeHg) exposure. Limited oceanic mercury (Hg) data, particularly MeHg, has confounded our understanding of linkages between sources, methylation sites, and concentrations in marine food webs. Here we present methylated (MeHg and dimethylmercury (Me</span><sub>2</sub><span>Hg)) and total Hg concentrations from 16 hydrographic stations in the eastern North Pacific Ocean. We use these data in combination with information from previous cruises and coupled atmospheric‐oceanic modeling results to better understand controls on Hg concentrations, distribution, and bioavailability. Total Hg concentrations (average 1.14 ± 0.38 pM) are elevated relative to previous cruises. Modeling results agree with observed increases and suggest that at present atmospheric Hg deposition rates, basin‐wide Hg concentrations will double relative to circa 1995 by 2050. Methylated Hg accounts for up to 29% of the total Hg in subsurface waters (average 260 ± 114 fM). We observed lower ambient methylated Hg concentrations in the euphotic zone and older, deeper water masses, which likely result from decay of MeHg and Me</span><sub>2</sub><span>Hg when net production is not occurring. We found a significant, positive linear relationship between methylated Hg concentrations and rates of organic carbon remineralization (</span><i>r</i><sup>2</sup><span>&nbsp;= 0.66,&nbsp;</span><i>p</i><span>&nbsp;&lt; 0.001). These results provide evidence for the importance of particulate organic carbon (POC) transport and remineralization on the production and distribution of methylated Hg species in marine waters. Specifically, settling POC provides a source of inorganic Hg(II) to microbially active subsurface waters and can also provide a substrate for microbial activity facilitating water column methylation.</span></p>","language":"English","publisher":"AGU","doi":"10.1029/2008GB003425","issn":"08866236","usgsCitation":"Sunderland, E., Krabbenhoft, D., Moreau, J., Strode, S., and Landing, W., 2009, Mercury sources, distribution, and bioavailability in the North Pacific Ocean: Insights from data and models: Global Biogeochemical Cycles, v. 23, no. 2, https://doi.org/10.1029/2008GB003425.","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":476220,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2008gb003425","text":"Publisher Index Page"},{"id":244560,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":216675,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1029/2008GB003425"}],"volume":"23","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a542de4b0c8380cd6ced7","contributors":{"authors":[{"text":"Sunderland, E.M.","contributorId":45546,"corporation":false,"usgs":true,"family":"Sunderland","given":"E.M.","email":"","affiliations":[],"preferred":false,"id":445335,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Krabbenhoft, D. P. 0000-0003-1964-5020","orcid":"https://orcid.org/0000-0003-1964-5020","contributorId":90765,"corporation":false,"usgs":true,"family":"Krabbenhoft","given":"D. P.","affiliations":[],"preferred":false,"id":445338,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Moreau, J.W.","contributorId":64457,"corporation":false,"usgs":true,"family":"Moreau","given":"J.W.","affiliations":[],"preferred":false,"id":445336,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Strode, S.A.","contributorId":73439,"corporation":false,"usgs":true,"family":"Strode","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":445337,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Landing, W.M.","contributorId":99303,"corporation":false,"usgs":true,"family":"Landing","given":"W.M.","email":"","affiliations":[],"preferred":false,"id":445339,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70032457,"text":"70032457 - 2009 - Case study of a full-scale evapotranspiration cover","interactions":[],"lastModifiedDate":"2018-10-12T09:47:52","indexId":"70032457","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2327,"text":"Journal of Geotechnical and Geoenvironmental Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Case study of a full-scale evapotranspiration cover","docAbstract":"<div class=\"NLM_sec NLM_sec_level_1 hlFld-Abstract\"><p>The design, construction, and performance analyses of a 6.1ha evapotranspiration (ET) landfill cover at the semiarid U.S. Army Fort Carson site, near Colorado Springs, Colo. are presented. Initial water-balance model simulations, using literature reported soil hydraulic data, aided selection of borrow-source soil type(s) that resulted in predictions of negligible annual drainage (⩽1mm∕year). Final construction design was based on refined water-balance simulations using laboratory determined soil hydraulic values from borrow area natural soil horizons that were described with USDA soil classification methods. Cover design components included a 122cm thick clay loam (USDA), compaction ⩽80% of the standard Proctor maximum dry density (dry bulk density ∼1.3Mg/m3), erosion control measures, top soil amended with biosolids, and seeding with native grasses. Favorable hydrologic performance for a 5year period was documented by lysimeter-measured and Richards’-based calculations of annual drainage that were all &lt;0.4mm∕year. Water potential data suggest that ET removed water that infiltrated the cover and contributed to a persistent driving force for upward flow and removal of water from below the base of the cover.</p></div>","language":"English","publisher":"ASCE","doi":"10.1061/(ASCE)1090-0241(2009)135:3(316)","usgsCitation":"McGuire, P.E., Andraski, B.J., and Archibald, R.E., 2009, Case study of a full-scale evapotranspiration cover: Journal of Geotechnical and Geoenvironmental Engineering, v. 135, no. 3, p. 316-332, https://doi.org/10.1061/(ASCE)1090-0241(2009)135:3(316).","productDescription":"17 p.","startPage":"316","endPage":"332","costCenters":[{"id":465,"text":"Nevada Water Science Center","active":true,"usgs":true},{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":241512,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"135","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f38ce4b0c8380cd4b88a","contributors":{"authors":[{"text":"McGuire, Patrick E.","contributorId":71008,"corporation":false,"usgs":false,"family":"McGuire","given":"Patrick","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":436257,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Andraski, Brian J. 0000-0002-2086-0417 andraski@usgs.gov","orcid":"https://orcid.org/0000-0002-2086-0417","contributorId":168800,"corporation":false,"usgs":true,"family":"Andraski","given":"Brian","email":"andraski@usgs.gov","middleInitial":"J.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true},{"id":465,"text":"Nevada Water Science Center","active":true,"usgs":true},{"id":38175,"text":"Toxics Substances Hydrology Program","active":true,"usgs":true}],"preferred":false,"id":436256,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Archibald, Ryan E.","contributorId":27277,"corporation":false,"usgs":false,"family":"Archibald","given":"Ryan","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":436255,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70032425,"text":"70032425 - 2009 - Groundwater's significance to changing hydrology, water chemistry, and biological communities of a floodplain ecosystem, Everglades, South Florida, USA","interactions":[],"lastModifiedDate":"2012-03-12T17:21:21","indexId":"70032425","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Groundwater's significance to changing hydrology, water chemistry, and biological communities of a floodplain ecosystem, Everglades, South Florida, USA","docAbstract":"The Everglades (Florida, USA) is one of the world's larger subtropical peatlands with biological communities adapted to waters low in total dissolved solids and nutrients. Detecting how the pre-drainage hydrological system has been altered is crucial to preserving its functional attributes. However, reliable tools for hindcasting historic conditions in the Everglades are limited. A recent synthesis demonstrates that the proportion of surface-water inflows has increased relative to precipitation, accounting for 33% of total inputs compared with 18% historically. The largest new source of water is canal drainage from areas of former wetlands converted to agriculture. Interactions between groundwater and surface water have also increased, due to increasing vertical hydraulic gradients resulting from topographic and water-level alterations on the otherwise extremely flat landscape. Environmental solute tracer data were used to determine groundwater's changing role, from a freshwater storage reservoir that sustained the Everglades ecosystem during dry periods to a reservoir of increasingly degraded water quality. Although some of this degradation is attributable to increased discharge of deep saline groundwater, other mineral sources such as fertilizer additives and peat oxidation have made a greater contribution to water-quality changes that are altering mineral-sensitive biological communities. ?? Springer-Verlag 2008.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrogeology Journal","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10040-008-0379-x","issn":"14312","usgsCitation":"Harvey, J., and McCormick, P., 2009, Groundwater's significance to changing hydrology, water chemistry, and biological communities of a floodplain ecosystem, Everglades, South Florida, USA: Hydrogeology Journal, v. 17, no. 1, p. 185-201, https://doi.org/10.1007/s10040-008-0379-x.","startPage":"185","endPage":"201","numberOfPages":"17","costCenters":[],"links":[{"id":476265,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1007/s10040-008-0379-x","text":"Publisher Index Page"},{"id":213879,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10040-008-0379-x"},{"id":241545,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"17","issue":"1","noUsgsAuthors":false,"publicationDate":"2008-10-29","publicationStatus":"PW","scienceBaseUri":"505a2dc4e4b0c8380cd5c004","contributors":{"authors":[{"text":"Harvey, J. W. 0000-0002-2654-9873","orcid":"https://orcid.org/0000-0002-2654-9873","contributorId":39725,"corporation":false,"usgs":true,"family":"Harvey","given":"J. W.","affiliations":[],"preferred":false,"id":436102,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"McCormick, P.V.","contributorId":93272,"corporation":false,"usgs":true,"family":"McCormick","given":"P.V.","email":"","affiliations":[],"preferred":false,"id":436103,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70034293,"text":"70034293 - 2009 - Comparing approaches for simulating the reactive transport of U(VI) in ground water","interactions":[],"lastModifiedDate":"2018-10-05T10:16:12","indexId":"70034293","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2745,"text":"Mine Water and the Environment","active":true,"publicationSubtype":{"id":10}},"title":"Comparing approaches for simulating the reactive transport of U(VI) in ground water","docAbstract":"<p><span>The reactive transport of U(VI) in a well-characterized shallow alluvial aquifer at a former U(VI) mill located near Naturita, CO, was predicted for comparative purposes using a surface complexation model (SCM) and a constant&nbsp;</span><i class=\"EmphasisTypeItalic \">K</i><span>&nbsp;</span><sub>d</sub><span>&nbsp;approach to simulate U(VI) adsorption. The ground water at the site had U(VI) concentrations that ranged from 0.01 to 20&nbsp;µM, alkalinities that ranged from 2.5 to 18&nbsp;meq/L, and a nearly constant pH of 7.1. The SCM used to simulate U(VI) adsorption was previously determined independently using laboratory batch adsorption experiments. Simulations obtained using the SCM approach were compared with simulations that used a constant&nbsp;</span><i class=\"EmphasisTypeItalic \">K</i><span>&nbsp;</span><sub>d</sub><span>&nbsp;approach to simulate adsorption using previously determined site-specific&nbsp;</span><i class=\"EmphasisTypeItalic \">K</i><span>&nbsp;</span><sub>d</sub><span>&nbsp;values. In both cases, the ground water flow and transport models used a conceptual model that was previously calibrated to a chloride plume present at the site. Simulations with the SCM approach demonstrated that the retardation factor varied temporally and spatially because of the differential transport of alkalinity and dissolved U(VI) and the nonlinearity of the U(VI) adsorption. The SCM model also simulated a prolonged slow decline in U(VI) concentration, which was not simulated using a constant&nbsp;</span><i class=\"EmphasisTypeItalic \">K</i><span>&nbsp;</span><sub>d</sub><span>&nbsp;model. Simulations using the SCM approach and the constant&nbsp;</span><i class=\"EmphasisTypeItalic \">K</i><span>&nbsp;</span><sub>d</sub><span>&nbsp;approach were similar after 20&nbsp;years of transport but diverged significantly after 60&nbsp;years. The simulations demonstrate the need for site-specific geochemical information on U(VI) adsorption to produce credible simulations of future transport.</span></p>","language":"English","publisher":"Springer","doi":"10.1007/s10230-009-0064-x","issn":"10259112","usgsCitation":"Curtis, G., Kohler, M., and Davis, J., 2009, Comparing approaches for simulating the reactive transport of U(VI) in ground water: Mine Water and the Environment, v. 28, no. 2, p. 84-93, https://doi.org/10.1007/s10230-009-0064-x.","productDescription":"10 p.","startPage":"84","endPage":"93","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":216793,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10230-009-0064-x"},{"id":244685,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"28","issue":"2","noUsgsAuthors":false,"publicationDate":"2009-02-20","publicationStatus":"PW","scienceBaseUri":"5059f831e4b0c8380cd4cf2a","contributors":{"authors":[{"text":"Curtis, G.P.","contributorId":65619,"corporation":false,"usgs":true,"family":"Curtis","given":"G.P.","email":"","affiliations":[],"preferred":false,"id":445117,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kohler, M.","contributorId":32694,"corporation":false,"usgs":true,"family":"Kohler","given":"M.","affiliations":[],"preferred":false,"id":445116,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Davis, J.A.","contributorId":71694,"corporation":false,"usgs":true,"family":"Davis","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":445118,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70037339,"text":"70037339 - 2009 - Dike intrusions into bituminous coal, Illinois Basin: H, C, N, O isotopic responses to rapid and brief heating","interactions":[],"lastModifiedDate":"2012-03-12T17:22:08","indexId":"70037339","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1759,"text":"Geochimica et Cosmochimica Acta","active":true,"publicationSubtype":{"id":10}},"title":"Dike intrusions into bituminous coal, Illinois Basin: H, C, N, O isotopic responses to rapid and brief heating","docAbstract":"Unlike long-term heating in subsiding sedimentary basins, the near-instantaneous thermal maturation of sedimentary organic matter near magmatic intrusions is comparable to artificial thermal maturation in the laboratory in terms of short duration and limited extent. This study investigates chemical and H, C, N, O isotopic changes in high volatile bituminous coal near two Illinois dike contacts and compares observed patterns and trends with data from other published studies and from artificial maturation experiments. Our study pioneers in quantifying isotopically exchangeable hydrogen and measuring the D/H (i.e., <sup>2</sup>H/<sup>1</sup>H) ratio of isotopically non-exchangeable organic hydrogen in kerogen near magmatic contacts. Thermal stress in coal caused a reduction of isotopically exchangeable hydrogen in kerogen from 5% to 6% in unaltered coal to 2-3% at contacts, mostly due to elimination of functional groups (e.g., {single bond}OH, {single bond}COOH, {single bond}NH<sub>2</sub>). In contrast to all previously published data on D/H in thermally matured organic matter, the more mature kerogen near the two dike contacts is D-depleted, which is attributed to (i) thermal elimination of D-enriched functional groups, and (ii) thermal drying of hydrologically isolated coal prior to the onset of cracking reactions, thereby precluding D-transfer from relatively D-enriched water into kerogen. Maxima in organic nitrogen concentration and in the atomic N/C ratio of kerogen at a distance of ???2.5 to ???3.5 m from the thicker dike indicate that reactive N-compounds had been pyrolytically liberated at high temperature closer to the contact, migrated through the coal seam, and recombined with coal kerogen in a zone of lower temperature. The same principle extends to organic carbon, because a strong ??<sup>13</sup>C<sub>kerogen</sub> vs. ??<sup>15</sup>N<sub>kerogen</sub> correlation across 5.5 m of coal adjacent to the thicker dike indicates that coal was functioning as a flow-through reactor along a dynamic thermal gradient facilitating back-reactions between mobile pyrolysis products from the hot zone as they encounter less hot kerogen. Vein and cell filling carbonate is most abundant in highest rank coals where carbonate ??<sup>13</sup>C<sub>VPDB</sub> and ??<sup>18</sup>O<sub>VSMOW</sub> values are consistent with thermal generation of <sup>13</sup>C-depleted and <sup>18</sup>O-enriched CO<sub>2</sub> from decarboxylation and pyrolysis of organic matter. Lower background concentrations of <sup>13</sup>C-enriched carbonate in thermally unaffected coal may be linked to <sup>13</sup>C-enrichment in residual CO<sub>2</sub> in the process of CO<sub>2</sub> reduction via microbial methanogenesis. Our compilation and comparison of available organic H, C, N isotopic findings on magmatic intrusions result in re-assessments of majors factors influencing isotopic shifts in kerogen during magmatic heating. (i) Thermally induced shifts in organic ??D values of kerogen are primarily driven by the availability of water or steam. Hydrologic isolation (e.g., near Illinois dikes) results in organic D-depletion in kerogen, whereas more common hydrologic connectivity results in organic D-enrichment. (ii) Shifts in kerogen (or coal) ??<sup>13</sup>C and ??<sup>15</sup>N values are typically small and may follow sinusoidal patterns over short distances from magmatic contacts. Laterally limited sampling strategies may thus result in misleading and non-representative data. (iii) Fluid transport of chemically active, mobile carbon and nitrogen species and recombination reactions with kerogen result in isotopic changes in kerogen that are unrelated to the original, autochthonous part of kerogen. ?? 2009 Elsevier Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geochimica et Cosmochimica Acta","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.gca.2009.07.027","issn":"00167037","usgsCitation":"Schimmelmann, A., Mastalerz, M., Gao, L., Sauer, P., and Topalov, K., 2009, Dike intrusions into bituminous coal, Illinois Basin: H, C, N, O isotopic responses to rapid and brief heating: Geochimica et Cosmochimica Acta, v. 73, no. 20, p. 6264-6281, https://doi.org/10.1016/j.gca.2009.07.027.","startPage":"6264","endPage":"6281","numberOfPages":"18","costCenters":[],"links":[{"id":217175,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.gca.2009.07.027"},{"id":245096,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"73","issue":"20","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a019de4b0c8380cd4fc8d","contributors":{"authors":[{"text":"Schimmelmann, A.","contributorId":28348,"corporation":false,"usgs":false,"family":"Schimmelmann","given":"A.","affiliations":[],"preferred":false,"id":460535,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mastalerz, Maria","contributorId":78065,"corporation":false,"usgs":true,"family":"Mastalerz","given":"Maria","affiliations":[],"preferred":false,"id":460538,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Gao, L.","contributorId":63651,"corporation":false,"usgs":true,"family":"Gao","given":"L.","email":"","affiliations":[],"preferred":false,"id":460536,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Sauer, P.E.","contributorId":76335,"corporation":false,"usgs":true,"family":"Sauer","given":"P.E.","email":"","affiliations":[],"preferred":false,"id":460537,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Topalov, K.","contributorId":82562,"corporation":false,"usgs":true,"family":"Topalov","given":"K.","email":"","affiliations":[],"preferred":false,"id":460539,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70037333,"text":"70037333 - 2009 - Analysis of hydromechanical well tests in fractured sedimentary rock at the NAWC site, New Jersey","interactions":[],"lastModifiedDate":"2020-03-10T14:50:24","indexId":"70037333","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Analysis of hydromechanical well tests in fractured sedimentary rock at the NAWC site, New Jersey","docAbstract":"<p>No abstract available.</p>","largerWorkType":{"id":4,"text":"Book"},"largerWorkTitle":"43rd U.S. Rock Mechanics Symposium and 4th U.S.-Canada Rock Mechanics Symposium","largerWorkSubtype":{"id":12,"text":"Conference publication"},"conferenceTitle":"43rd U.S. Rock Mechanics Symposium and 4th U.S.-Canada Rock Mechanics Symposium","conferenceDate":"June 28- July 1, 2009","conferenceLocation":"Asheville, NC","language":"English","usgsCitation":"Murdoch, L., Hisz, D., Ebenhack, J., Fowler, D., Tiedeman, C.R., and Germanovich, L., 2009, Analysis of hydromechanical well tests in fractured sedimentary rock at the NAWC site, New Jersey, <i>in</i> 43rd U.S. Rock Mechanics Symposium and 4th U.S.-Canada Rock Mechanics Symposium, Asheville, NC, June 28- July 1, 2009.","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":245004,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"New 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D.E.","contributorId":83363,"corporation":false,"usgs":true,"family":"Fowler","given":"D.E.","email":"","affiliations":[],"preferred":false,"id":460515,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Tiedeman, C. R.","contributorId":104107,"corporation":false,"usgs":true,"family":"Tiedeman","given":"C.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":460516,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Germanovich, L.N.","contributorId":81342,"corporation":false,"usgs":true,"family":"Germanovich","given":"L.N.","email":"","affiliations":[],"preferred":false,"id":460514,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70037312,"text":"70037312 - 2009 - Relationship between body condition of American alligators and water depth in the Everglades, Florida","interactions":[],"lastModifiedDate":"2013-04-08T14:29:07","indexId":"70037312","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1919,"text":"Hydrobiologia","onlineIssn":"1573-5117","printIssn":"0018-8158","active":true,"publicationSubtype":{"id":10}},"title":"Relationship between body condition of American alligators and water depth in the Everglades, Florida","docAbstract":"Feeding opportunities of American alligators (Alligator mississippiensis) in freshwater wetlands in south Florida are closely linked to hydrologic conditions. In the Everglades, seasonally and annually fluctuating surface water levels affect populations of aquatic organisms that alligators consume. Since prey becomes more concentrated when water depth decreases, we hypothesized an inverse relationship between body condition and water depth in the Everglades. On average, condition of adult alligators in the dry season was significantly higher than in the wet season, but this was not the case for juveniles/subadults. The correlation between body condition and measured water depth at capture locations was weak; however, there was a significant negative correlation between the condition and predicted water depth prior to capture for all animals except for spring juveniles/subadults which had a weak positive condition-water depth relationship. Overall, a relatively strong inverse correlation occurred at 10-49 days prior to the capture day, suggesting that current body condition of alligators may depend on feeding opportunities during that period. Fitted regression of body condition on water depth (mean depth of 10 days when condition-water depth correlation was greatest) resulted in a significantly negative slope, except for spring adult females and spring juveniles/subadults for which slopes were not significantly different from zero. Our results imply that water management practices may be critical for alligators in the Everglades since water depth can affect animal condition in a relatively short period of time.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Hydrobiologia","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Springer","publisherLocation":"Amsterdam, Netherlands","doi":"10.1007/s10750-009-9925-3","issn":"00188158","usgsCitation":"Fujisaki, I., Rice, K.G., Pearlstine, L.G., and Mazzotti, F., 2009, Relationship between body condition of American alligators and water depth in the Everglades, Florida: Hydrobiologia, v. 635, no. 1, p. 329-338, https://doi.org/10.1007/s10750-009-9925-3.","startPage":"329","endPage":"338","numberOfPages":"10","additionalOnlineFiles":"N","costCenters":[{"id":566,"text":"Southeast Ecological Science Center","active":true,"usgs":true}],"links":[{"id":217260,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10750-009-9925-3"},{"id":245191,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"635","issue":"1","noUsgsAuthors":false,"publicationDate":"2009-08-27","publicationStatus":"PW","scienceBaseUri":"50e4a72be4b0e8fec6cdc3d6","contributors":{"authors":[{"text":"Fujisaki, Ikuko","contributorId":31108,"corporation":false,"usgs":false,"family":"Fujisaki","given":"Ikuko","email":"","affiliations":[{"id":12557,"text":"University of Florida, FLREC","active":true,"usgs":false}],"preferred":false,"id":460421,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rice, Kenneth G. 0000-0001-8282-1088 krice@usgs.gov","orcid":"https://orcid.org/0000-0001-8282-1088","contributorId":117,"corporation":false,"usgs":true,"family":"Rice","given":"Kenneth","email":"krice@usgs.gov","middleInitial":"G.","affiliations":[{"id":566,"text":"Southeast Ecological Science Center","active":true,"usgs":true},{"id":17705,"text":"Wetland and Aquatic Research Center","active":true,"usgs":true}],"preferred":true,"id":460420,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Pearlstine, Leonard G.","contributorId":34751,"corporation":false,"usgs":false,"family":"Pearlstine","given":"Leonard","email":"","middleInitial":"G.","affiliations":[{"id":12462,"text":"U.S. Department of the Interior, National Park Service","active":true,"usgs":false}],"preferred":false,"id":460422,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Mazzotti, Frank J.","contributorId":100018,"corporation":false,"usgs":false,"family":"Mazzotti","given":"Frank J.","affiliations":[{"id":12557,"text":"University of Florida, FLREC","active":true,"usgs":false}],"preferred":false,"id":460423,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70037309,"text":"70037309 - 2009 - Greenhouse gas flux from cropland and restored wetlands in the Prairie Pothole Region","interactions":[],"lastModifiedDate":"2017-10-26T11:03:42","indexId":"70037309","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3416,"text":"Soil Biology and Biochemistry","active":true,"publicationSubtype":{"id":10}},"title":"Greenhouse gas flux from cropland and restored wetlands in the Prairie Pothole Region","docAbstract":"It has been well documented that restored wetlands in the Prairie Pothole Region of North America do store carbon. However, the net benefit of carbon sequestration in wetlands in terms of a reduction in global warming forcing has often been questioned because of potentially greater emissions of greenhouse gases (GHGs) such as nitrous oxide (N<sub>2</sub>O) and methane (CH<sub>4</sub>). We compared gas emissions (N<sub>2</sub>O, CH<sub>4</sub>, carbon dioxide [CO<sub>2</sub>]) and soil moisture and temperature from eight cropland and eight restored grassland wetlands in the Prairie Pothole Region from May to October, 2003, to better understand the atmospheric carbon mitigation potential of restored wetlands. Results show that carbon dioxide contributed the most (90%) to net-GHG flux, followed by CH<sub>4</sub> (9%) and N<sub>2</sub>O (1%). Fluxes of N<sub>2</sub>O, CH<sub>4</sub>, CO<sub>2</sub>, and their combined global warming potential (CO<sub>2</sub> equivalents) did not significantly differ between cropland and grassland wetlands. The seasonal pattern in flux was similar in cropland and grassland wetlands with peak emissions of N<sub>2</sub>O and CH<sub>4</sub> occurring when soil water-filled pore space (WFPS) was 40-60% and &gt;60%, respectively; negative CH<sub>4</sub> fluxes were observed when WFPS approached 40%. Negative CH<sub>4</sub> fluxes from grassland wetlands occurred earlier in the season and were more pronounced than those from cropland sites because WFPS declined more rapidly in grassland wetlands; this decline was likely due to higher infiltration and evapotranspiration rates associated with grasslands. Our results suggest that restoring cropland wetlands does not result in greater emissions of N<sub>2</sub>O and CH<sub>4</sub>, and therefore would not offset potential soil carbon sequestration. These findings, however, are limited to a small sample of seasonal wetlands with relatively short hydroperiods. A more comprehensive assessment of the GHG mitigation potential of restored wetlands should include a diversity of wetland types and land-use practices and consider the impact of variable climatic cycles that affect wetland hydrology.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Soil Biology and Biochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.soilbio.2009.09.008","issn":"00380717","usgsCitation":"Gleason, R., Tangen, B., Browne, B., and Euliss, N., 2009, Greenhouse gas flux from cropland and restored wetlands in the Prairie Pothole Region: Soil Biology and Biochemistry, v. 41, no. 12, p. 2501-2507, https://doi.org/10.1016/j.soilbio.2009.09.008.","productDescription":"7 p.","startPage":"2501","endPage":"2507","numberOfPages":"7","costCenters":[{"id":480,"text":"Northern Prairie Wildlife Research Center","active":true,"usgs":true}],"links":[{"id":245156,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":217229,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.soilbio.2009.09.008"}],"volume":"41","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2a6be4b0c8380cd5b168","contributors":{"authors":[{"text":"Gleason, R.A.","contributorId":46035,"corporation":false,"usgs":true,"family":"Gleason","given":"R.A.","email":"","affiliations":[],"preferred":false,"id":460407,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Tangen, B.A.","contributorId":102687,"corporation":false,"usgs":true,"family":"Tangen","given":"B.A.","email":"","affiliations":[],"preferred":false,"id":460410,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Browne, B.A.","contributorId":85006,"corporation":false,"usgs":true,"family":"Browne","given":"B.A.","email":"","affiliations":[],"preferred":false,"id":460409,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Euliss, N.H. Jr.","contributorId":54917,"corporation":false,"usgs":true,"family":"Euliss","given":"N.H.","suffix":"Jr.","email":"","affiliations":[],"preferred":false,"id":460408,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70037305,"text":"70037305 - 2009 - Synergistic use of optical and InSAR data for urban impervious surface mapping: A case study in Hong Kong","interactions":[],"lastModifiedDate":"2017-04-03T16:07:12","indexId":"70037305","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2068,"text":"International Journal of Remote Sensing","active":true,"publicationSubtype":{"id":10}},"title":"Synergistic use of optical and InSAR data for urban impervious surface mapping: A case study in Hong Kong","docAbstract":"<p><span>A wide range of urban ecosystem studies, including urban hydrology, urban climate, land use planning and watershed resource management, require accurate and up‐to‐date geospatial data of urban impervious surfaces. In this study, the potential of the synergistic use of optical and InSAR data in urban impervious surface mapping at the sub‐pixel level was investigated. A case study in Hong Kong was conducted for this purpose by applying a classification and regression tree (CART) algorithm to SPOT 5 multispectral imagery and ERS‐2 SAR data. Validated by reference data derived from high‐resolution colour‐infrared (CIR) aerial photographs, our results show that the addition of InSAR feature information can improve the estimation of impervious surface percentage (ISP) in comparison with using SPOT imagery alone. The improvement is especially notable in separating urban impervious surface from the vacant land/bare ground, which has been a difficult task in ISP modelling with optical remote sensing data. In addition, the results demonstrate the potential to map urban impervious surface by using InSAR data alone. This allows frequent monitoring of world's cities located in cloud‐prone and rainy areas.</span></p>","language":"English","publisher":"Taylor & Francis","doi":"10.1080/01431160802555838","issn":"01431161","usgsCitation":"Jiang, L., Liao, M., Lin, H., and Yang, L., 2009, Synergistic use of optical and InSAR data for urban impervious surface mapping: A case study in Hong Kong: International Journal of Remote Sensing, v. 30, no. 11, p. 2781-2796, https://doi.org/10.1080/01431160802555838.","productDescription":"16 p.","startPage":"2781","endPage":"2796","numberOfPages":"16","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":245036,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":217119,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1080/01431160802555838"}],"volume":"30","issue":"11","noUsgsAuthors":false,"publicationDate":"2009-06-22","publicationStatus":"PW","scienceBaseUri":"505ba340e4b08c986b31fc2b","contributors":{"authors":[{"text":"Jiang, L.","contributorId":107530,"corporation":false,"usgs":true,"family":"Jiang","given":"L.","email":"","affiliations":[],"preferred":false,"id":460369,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Liao, M.","contributorId":86600,"corporation":false,"usgs":true,"family":"Liao","given":"M.","email":"","affiliations":[],"preferred":false,"id":460368,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lin, H.","contributorId":17854,"corporation":false,"usgs":true,"family":"Lin","given":"H.","email":"","affiliations":[],"preferred":false,"id":460367,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Yang, L.","contributorId":6200,"corporation":false,"usgs":true,"family":"Yang","given":"L.","affiliations":[],"preferred":false,"id":460366,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70037282,"text":"70037282 - 2009 - Instrumental record of debris flow initiation during natural rainfall: Implications for modeling slope stability","interactions":[],"lastModifiedDate":"2020-11-24T22:29:48.316269","indexId":"70037282","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2318,"text":"Journal of Geophysical Research F: Earth Surface","active":true,"publicationSubtype":{"id":10}},"title":"Instrumental record of debris flow initiation during natural rainfall: Implications for modeling slope stability","docAbstract":"<p><span id=\"_mce_caret\" data-mce-bogus=\"1\" data-mce-type=\"format-caret\"><span class=\"paraNumber\"><span></span></span></span><span>The middle of a hillslope hollow in the Oregon Coast Range failed and mobilized as a debris flow during heavy rainfall in November 1996. Automated pressure transducers recorded high spatial variability of pore water pressure within the area that mobilized as a debris flow, which initiated where local upward flow from bedrock developed into overlying colluvium. Postfailure observations of the bedrock surface exposed in the debris flow scar reveal a strong spatial correspondence between elevated piezometric response and water discharging from bedrock fractures. Measurements of apparent root cohesion on the basal (</span><i>C</i><sub><i>b</i></sub><span>) and lateral (</span><i>C</i><sub><i>l</i></sub><span>) scarp demonstrate substantial local variability, with areally weighted values of&nbsp;</span><i>C</i><sub><i>b</i></sub><span>&nbsp;= 0.1 and&nbsp;</span><i>C</i><sub><i>l</i></sub><span>&nbsp;= 4.6 kPa. Using measured soil properties and basal root strength, the widely used infinite slope model, employed assuming slope parallel groundwater flow, provides a poor prediction of hydrologic conditions at failure. In contrast, a model including lateral root strength (but neglecting lateral frictional strength) gave a predicted critical value of relative soil saturation that fell within the range defined by the arithmetic and geometric mean values at the time of failure. The 3‐D slope stability model CLARA‐W, used with locally observed pore water pressure, predicted small areas with lower factors of safety within the overall slide mass at sites consistent with field observations of where the failure initiated. This highly variable and localized nature of small areas of high pore pressure that can trigger slope failure means, however, that substantial uncertainty appears inevitable for estimating hydrologic conditions within incipient debris flows under natural conditions.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2008JF001078","usgsCitation":"Montgomery, D.R., Schmidt, K., Dietrich, W.E., and McKean, J., 2009, Instrumental record of debris flow initiation during natural rainfall: Implications for modeling slope stability: Journal of Geophysical Research F: Earth Surface, v. 114, no. F1, F01031, 16 p., https://doi.org/10.1029/2008JF001078.","productDescription":"F01031, 16 p.","costCenters":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true}],"links":[{"id":476367,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2008jf001078","text":"Publisher Index Page"},{"id":245189,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Oregon","otherGeospatial":"Mettman Ridge","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -124.47509765625,\n              43.17313537107136\n            ],\n            [\n              -123.914794921875,\n              43.17313537107136\n            ],\n            [\n              -123.914794921875,\n              43.691707903073805\n            ],\n            [\n              -124.47509765625,\n              43.691707903073805\n            ],\n            [\n              -124.47509765625,\n              43.17313537107136\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"114","issue":"F1","noUsgsAuthors":false,"publicationDate":"2009-03-12","publicationStatus":"PW","scienceBaseUri":"505a3c46e4b0c8380cd62bf0","contributors":{"authors":[{"text":"Montgomery, D. R.","contributorId":41582,"corporation":false,"usgs":false,"family":"Montgomery","given":"D.","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":460260,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schmidt, K. M. 0000-0003-2365-8035","orcid":"https://orcid.org/0000-0003-2365-8035","contributorId":59830,"corporation":false,"usgs":true,"family":"Schmidt","given":"K. M.","affiliations":[{"id":312,"text":"Geology, Minerals, Energy, and Geophysics Science Center","active":true,"usgs":true}],"preferred":false,"id":460262,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dietrich, W. E.","contributorId":47538,"corporation":false,"usgs":false,"family":"Dietrich","given":"W.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":460261,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"McKean, J.","contributorId":60054,"corporation":false,"usgs":true,"family":"McKean","given":"J.","affiliations":[],"preferred":false,"id":460263,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70037248,"text":"70037248 - 2009 - A comparison of pre- and post-remediation water quality, Mineral Creek, Colorado","interactions":[],"lastModifiedDate":"2018-10-12T09:58:33","indexId":"70037248","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1924,"text":"Hydrological Processes","active":true,"publicationSubtype":{"id":10}},"title":"A comparison of pre- and post-remediation water quality, Mineral Creek, Colorado","docAbstract":"Pre- and post-remediation data sets are used herein to assess the effectiveness of remedial measures implemented in the headwaters of the Mineral Creek watershed, where contamination from hard rock mining has led to elevated metal concentrations and acidic pH. Collection of pre- and post-remediation data sets generally followed the synoptic mass balance approach, in which numerous stream and inflow locations are sampled for the constituents of interest and estimates of streamflow are determined by tracer dilution. The comparison of pre- and post-remediation data sets is confounded by hydrologic effects and the effects of temporal variation. Hydrologic effects arise due to the relatively wet conditions that preceded the collection of pre-remediation data, and the relatively dry conditions associated with the post-remediation data set. This difference leads to a dilution effect in the upper part of the study reach, where pre-remediation concentrations were diluted by rainfall, and a source area effect in the lower part of the study reach, where a smaller portion of the watershed may have been contributing constituent mass during the drier post-remediation period. A second confounding factor, temporal variability, violates the steady-state assumption that underlies the synoptic mass balance approach, leading to false identification of constituent sources and sinks. Despite these complications, remedial actions completed in the Mineral Creek headwaters appear to have led to improvements in stream water quality, as post-remediation profiles of instream load are consistently lower than the pre-remediation profiles over the entire study reach for six of the eight constituents considered (aluminium, arsenic, cadmium, copper, iron, and zinc). Concentrations of aluminium, cadmium, copper, lead, and zinc remain above chronic aquatic-life standards, however, and additional remedial actions may be needed. Future implementations of the synoptic mass balance approach should be preceded by an assessment of temporal variability, and modifications to the synoptic sampling protocol should be made if necessary.","language":"English","publisher":"Wiley","doi":"10.1002/hyp.7427","issn":"08856087","usgsCitation":"Runkel, R., Bencala, K., Kimball, B.A., Walton-Day, K., and Verplanck, P., 2009, A comparison of pre- and post-remediation water quality, Mineral Creek, Colorado: Hydrological Processes, v. 23, no. 23, p. 3319-3333, https://doi.org/10.1002/hyp.7427.","productDescription":"15 p.","startPage":"3319","endPage":"3333","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":245152,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":217225,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1002/hyp.7427"}],"country":"United States","state":"Colorado","otherGeospatial":"Mineral Creek","geographicExtents":"{ \"type\": \"FeatureCollection\", \"features\": [ { \"type\": \"Feature\", \"properties\": {}, \"geometry\": { \"type\": \"Polygon\", \"coordinates\": [ [ [ -109.0,37.0 ], [ -109.0,41.0 ], [ -102.0,41.0 ], [ -102.0,37.0 ], [ -109.0,37.0 ] ] ] } } ] }","volume":"23","issue":"23","noUsgsAuthors":false,"publicationDate":"2009-09-15","publicationStatus":"PW","scienceBaseUri":"5059e370e4b0c8380cd46007","contributors":{"authors":[{"text":"Runkel, R.L.","contributorId":97529,"corporation":false,"usgs":true,"family":"Runkel","given":"R.L.","affiliations":[],"preferred":false,"id":460070,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Bencala, K.E.","contributorId":105312,"corporation":false,"usgs":true,"family":"Bencala","given":"K.E.","email":"","affiliations":[],"preferred":false,"id":460071,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Kimball, B. A.","contributorId":87583,"corporation":false,"usgs":false,"family":"Kimball","given":"B.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":460069,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Walton-Day, K.","contributorId":14054,"corporation":false,"usgs":true,"family":"Walton-Day","given":"K.","affiliations":[],"preferred":false,"id":460068,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Verplanck, P. L. 0000-0002-3653-6419","orcid":"https://orcid.org/0000-0002-3653-6419","contributorId":106565,"corporation":false,"usgs":true,"family":"Verplanck","given":"P. L.","affiliations":[],"preferred":false,"id":460072,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70037244,"text":"70037244 - 2009 - Elevated naturally occurring arsenic in a semiarid oxidizing system, Southern High Plains aquifer, Texas, USA","interactions":[],"lastModifiedDate":"2018-10-03T10:13:20","indexId":"70037244","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Elevated naturally occurring arsenic in a semiarid oxidizing system, Southern High Plains aquifer, Texas, USA","docAbstract":"<p><span>High groundwater As concentrations in oxidizing systems are generally associated with As adsorption onto hydrous metal (Al, Fe or Mn) oxides and mobilization with increased pH. The objective of this study was to evaluate the distribution, sources and mobilization mechanisms of As in the Southern High Plains (SHP) aquifer, Texas, relative to those in other semiarid, oxidizing systems. Elevated groundwater As levels are widespread in the southern part of the SHP (SHP-S) aquifer, with 47% of wells exceeding the current EPA maximum contaminant level (MCL) of 10&nbsp;μg/L (range 0.3–164&nbsp;μg/L), whereas As levels are much lower in the north (SHP-N: 9%&nbsp;⩾&nbsp;As MCL of 10&nbsp;μg/L; range 0.2–43&nbsp;μg/L). The sharp contrast in As levels between the north and south coincides with a change in total dissolved solids (TDS) from 395&nbsp;mg/L (median north) to 885&nbsp;mg/L (median south). Arsenic is present as arsenate (As V) in this oxidizing system and is correlated with groundwater TDS (Spearman’s </span><i>ρ</i><span>&nbsp;=&nbsp;0.57). The most likely current source of As is sorbed As onto hydrous metal oxides based on correlations between As and other oxyanion-forming elements (V, </span><i>ρ</i><span>&nbsp;=&nbsp;0.88; Se, </span><i>ρ</i><span>&nbsp;=&nbsp;0.54; B, </span><i>ρ</i><span>&nbsp;=&nbsp;0.51 and Mo, </span><i>ρ</i><span>&nbsp;=&nbsp;0.46). This source is similar to that in other oxidizing systems and constitutes a secondary source; the most likely primary source being volcanic ashes in the SHP aquifer or original source rocks in the Rockies, based on co-occurrence of As and F (</span><i>ρ</i><span>&nbsp;=&nbsp;0.56), oxyanion-forming elements and SiO</span><sub>2</sub><span> (</span><i>ρ</i><span>&nbsp;=&nbsp;0.41), which are found in volcanic ashes. High groundwater As concentrations in some semiarid oxidizing systems are related to high evaporation. Although correlation of As with TDS in the SHP aquifer may suggest evaporative concentration, unenriched stable isotopes (δ</span><sup>2</sup><span>H: −65 to −27; δ</span><sup>18</sup><span>O: −9.1 to −4.2) in the SHP aquifer do not support evaporation. High TDS in the SHP aquifer is most likely related to upward movement of saline water from the underlying Triassic Dockum aquifer. Mobilization of As in other semiarid oxidizing systems is caused by increased pH; however, pH in the SHP aquifer is near neutral (10–90 percentiles, 7.0–7.6). Although many processes, such as competitive desorption with SiO</span><sub>2</sub><span>, VO</span><sub>4</sub><span>, or PO</span><sub>4</sub><span>, could be responsible for local mobilization of As in the SHP aquifer, the most plausible explanation for the regional As distribution and correlation with TDS is the counterion effect caused by a change from Ca- to Na-rich, water as shown by the high correlation between As and Na/(Ca)</span><sup>0.5</sup><span> ratios (</span><i>ρ</i><span>&nbsp;=&nbsp;0.57). This change in chemistry is related to mixing with saline water that moves upward from the underlying Dockum aquifer. This counterion effect may mobilize other anions and oxyanion-forming elements that are correlated with As (F, V, Se, B, Mo and SiO</span><sub>2</sub><span>). Competition among the oxyanions for sorption sites may enhance As mobilization. The SHP case study has similar As sources to those of other semiarid, oxidizing systems (original volcanic ash source followed by sorption onto hydrous metal oxides) but contrasts with these systems by showing lack of evaporative concentration and pH mobilization of As but counterion mobilization of As instead in the SHP-S aquifer.</span></p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.apgeochem.2009.08.004","usgsCitation":"Scanlon, B., Nicot, J., Reedy, R., Kurtzman, D., Mukherjee, A., and Nordstrom, D.K., 2009, Elevated naturally occurring arsenic in a semiarid oxidizing system, Southern High Plains aquifer, Texas, USA: Applied Geochemistry, v. 24, no. 11, p. 2061-2071, https://doi.org/10.1016/j.apgeochem.2009.08.004.","productDescription":"11 p.","startPage":"2061","endPage":"2071","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":245091,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Texas","otherGeospatial":"Southern High Plains aquifer","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -103.040771484375,\n              36.18665862660454\n            ],\n            [\n              -103.0517578125,\n              31.970803930433096\n            ],\n            [\n              -102.974853515625,\n              31.541089879585808\n            ],\n            [\n              -102.65625,\n              31.44741029142872\n            ],\n            [\n              -100.8984375,\n              31.531726144517158\n            ],\n            [\n            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D.","contributorId":98979,"corporation":false,"usgs":true,"family":"Kurtzman","given":"D.","email":"","affiliations":[],"preferred":false,"id":460055,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Mukherjee, A.","contributorId":82832,"corporation":false,"usgs":true,"family":"Mukherjee","given":"A.","email":"","affiliations":[],"preferred":false,"id":460052,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Nordstrom, D. Kirk 0000-0003-3283-5136 dkn@usgs.gov","orcid":"https://orcid.org/0000-0003-3283-5136","contributorId":749,"corporation":false,"usgs":true,"family":"Nordstrom","given":"D.","email":"dkn@usgs.gov","middleInitial":"Kirk","affiliations":[{"id":37277,"text":"WMA - Earth System Processes Division","active":true,"usgs":true},{"id":5044,"text":"National Research Program - Central Branch","active":true,"usgs":true}],"preferred":false,"id":460054,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70037243,"text":"70037243 - 2009 - Effects of introduced fish on macroinvertebrate communities in historically fishless headwater and kettle lakes","interactions":[],"lastModifiedDate":"2017-05-10T10:43:07","indexId":"70037243","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1015,"text":"Biological Conservation","active":true,"publicationSubtype":{"id":10}},"title":"Effects of introduced fish on macroinvertebrate communities in historically fishless headwater and kettle lakes","docAbstract":"<p><span>Widespread fish introductions have led to a worldwide decline in the number of fishless lakes and their associated communities. Studies assessing effects of fish stocking on native communities in historically fishless lakes have been limited to high-elevation headwater lakes stocked with non-native trout. Little is known about the effect of fish stocking in historically fishless and hydrologically isolated lowland kettle lakes. We compared the effects of introduced fish on macroinvertebrate communities in kettle lakes stocked with centrarchids, salmonids, and cyprinids, and headwater lakes stocked with brook trout (</span><i>Salvelinus fontinalis</i><span>) in Maine, USA. Fish had significant effects on macroinvertebrate community structure in both lake types, with reduced species richness and abundances of taxa characteristic of fishless lakes. The effects of introduced fish were more pronounced in headwater lakes despite a less diverse fish assemblage than in kettle lakes. We attribute this to abundant submerged vegetation providing refuge from fish predation and reduced stocking frequency in kettle lakes. We assessed effects of stocking duration on macroinvertebrates in a subset of headwater lakes with known dates of trout introduction. Species richness and abundance of most taxa declined within 3&nbsp;years following trout introduction; however, richness and abundance were least in lakes with long stocking histories (&ge;40&nbsp;years). Macroinvertebrates previously identified as fishless bioindicators were absent from all stocked lakes, indicating that trout rapidly eliminate these sensitive taxa. Conservation of this historically undervalued ecosystem requires protecting remaining fishless lakes and recovering those that have been stocked.</span></p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.biocon.2009.08.003","issn":"00063207","usgsCitation":"Schilling, E., Loftin, C., and Huryn, A.D., 2009, Effects of introduced fish on macroinvertebrate communities in historically fishless headwater and kettle lakes: Biological Conservation, v. 142, no. 12, p. 3030-3038, https://doi.org/10.1016/j.biocon.2009.08.003.","productDescription":"9 p.","startPage":"3030","endPage":"3038","numberOfPages":"9","onlineOnly":"N","additionalOnlineFiles":"N","ipdsId":"IP-008370","costCenters":[{"id":199,"text":"Coop Res Unit Leetown","active":true,"usgs":true}],"links":[{"id":245063,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":217144,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.biocon.2009.08.003"}],"country":"United States","state":"Maine","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -71.0101318359375,\n              44.3002644115815\n            ],\n            [\n              -71.0760498046875,\n              45.205263456162385\n            ],\n            [\n              -70.83984375,\n              45.24395342262324\n            ],\n            [\n              -70.59814453125,\n              45.6101948758674\n            ],\n            [\n              -70.24658203125,\n              45.954968795113395\n            ],\n            [\n              -69.093017578125,\n              45.84793427349226\n            ],\n            [\n              -67.97241210937499,\n              45.40230699238177\n            ],\n            [\n              -67.39562988281249,\n              44.680371641890375\n            ],\n            [\n              -67.8131103515625,\n              44.64911632343077\n            ],\n            [\n              -68.0712890625,\n              44.50434127765394\n            ],\n            [\n              -68.4173583984375,\n              44.50434127765394\n            ],\n            [\n              -69.36767578124999,\n              45.10066901851988\n            ],\n            [\n              -71.0101318359375,\n              44.3002644115815\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"142","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0729e4b0c8380cd515b0","contributors":{"authors":[{"text":"Schilling, Emily Gaenzle","contributorId":66069,"corporation":false,"usgs":false,"family":"Schilling","given":"Emily Gaenzle","affiliations":[{"id":7063,"text":"University of Maine","active":true,"usgs":false}],"preferred":false,"id":460049,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Loftin, Cynthia S. 0000-0001-9104-3724 cyndy_loftin@usgs.gov","orcid":"https://orcid.org/0000-0001-9104-3724","contributorId":2167,"corporation":false,"usgs":true,"family":"Loftin","given":"Cynthia S.","email":"cyndy_loftin@usgs.gov","affiliations":[],"preferred":true,"id":460050,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Huryn, Alexander D. 0000-0002-1365-2361","orcid":"https://orcid.org/0000-0002-1365-2361","contributorId":20164,"corporation":false,"usgs":false,"family":"Huryn","given":"Alexander","email":"","middleInitial":"D.","affiliations":[{"id":28219,"text":"The University of Alabama, Department of Biological Sciences, Tuscaloosa, AL 35487","active":true,"usgs":false}],"preferred":false,"id":460048,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70037239,"text":"70037239 - 2009 - Combining particle-tracking and geochemical data to assess public supply well vulnerability to arsenic and uranium","interactions":[],"lastModifiedDate":"2012-03-12T17:22:08","indexId":"70037239","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Combining particle-tracking and geochemical data to assess public supply well vulnerability to arsenic and uranium","docAbstract":"Flow-model particle-tracking results and geochemical data from seven study areas across the United States were analyzed using three statistical methods to test the hypothesis that these variables can successfully be used to assess public supply well vulnerability to arsenic and uranium. Principal components analysis indicated that arsenic and uranium concentrations were associated with particle-tracking variables that simulate time of travel and water fluxes through aquifer systems and also through specific redox and pH zones within aquifers. Time-of-travel variables are important because many geochemical reactions are kinetically limited, and geochemical zonation can account for different modes of mobilization and fate. Spearman correlation analysis established statistical significance for correlations of arsenic and uranium concentrations with variables derived using the particle-tracking routines. Correlations between uranium concentrations and particle-tracking variables were generally strongest for variables computed for distinct redox zones. Classification tree analysis on arsenic concentrations yielded a quantitative categorical model using time-of-travel variables and solid-phase-arsenic concentrations. The classification tree model accuracy on the learning data subset was 70%, and on the testing data subset, 79%, demonstrating one application in which particle-tracking variables can be used predictively in a quantitative screening-level assessment of public supply well vulnerability. Ground-water management actions that are based on avoidance of young ground water, reflecting the premise that young ground water is more vulnerable to anthropogenic contaminants than is old ground water, may inadvertently lead to increased vulnerability to natural contaminants due to the tendency for concentrations of many natural contaminants to increase with increasing ground-water residence time.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jhydrol.2009.07.020","issn":"00221694","usgsCitation":"Hinkle, S., Kauffman, L.J., Thomas, M., Brown, C.J., McCarthy, K.A., Eberts, S.M., Rosen, M.R., and Katz, B., 2009, Combining particle-tracking and geochemical data to assess public supply well vulnerability to arsenic and uranium: Journal of Hydrology, v. 376, no. 1-2, p. 132-142, https://doi.org/10.1016/j.jhydrol.2009.07.020.","startPage":"132","endPage":"142","numberOfPages":"11","costCenters":[],"links":[{"id":217086,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2009.07.020"},{"id":244999,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"376","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f7e0e4b0c8380cd4cd49","contributors":{"authors":[{"text":"Hinkle, S.R.","contributorId":74778,"corporation":false,"usgs":true,"family":"Hinkle","given":"S.R.","email":"","affiliations":[],"preferred":false,"id":460027,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kauffman, L. J. 0000-0003-4564-0362","orcid":"https://orcid.org/0000-0003-4564-0362","contributorId":65217,"corporation":false,"usgs":true,"family":"Kauffman","given":"L.","email":"","middleInitial":"J.","affiliations":[{"id":470,"text":"New Jersey Water Science Center","active":true,"usgs":true}],"preferred":false,"id":460025,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Thomas, M.A.","contributorId":66877,"corporation":false,"usgs":true,"family":"Thomas","given":"M.A.","email":"","affiliations":[],"preferred":false,"id":460026,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Brown, C. J.","contributorId":90342,"corporation":false,"usgs":true,"family":"Brown","given":"C.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":460029,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"McCarthy, K. A.","contributorId":107309,"corporation":false,"usgs":true,"family":"McCarthy","given":"K.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":460030,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Eberts, S. M.","contributorId":28276,"corporation":false,"usgs":true,"family":"Eberts","given":"S.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":460023,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Rosen, Michael R.","contributorId":43096,"corporation":false,"usgs":true,"family":"Rosen","given":"Michael","email":"","middleInitial":"R.","affiliations":[],"preferred":false,"id":460024,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Katz, B. G.","contributorId":82702,"corporation":false,"usgs":true,"family":"Katz","given":"B. G.","affiliations":[],"preferred":false,"id":460028,"contributorType":{"id":1,"text":"Authors"},"rank":8}]}}
,{"id":70037214,"text":"70037214 - 2009 - Biological soil crusts exhibit a dynamic response to seasonal rain and release from grazing with implications for soil stability","interactions":[],"lastModifiedDate":"2012-03-12T17:22:07","indexId":"70037214","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2183,"text":"Journal of Arid Environments","active":true,"publicationSubtype":{"id":10}},"title":"Biological soil crusts exhibit a dynamic response to seasonal rain and release from grazing with implications for soil stability","docAbstract":"In Northern Mexico, long-term grazing has substantially degraded semiarid landscapes. In semiarid systems, ecological and hydrological processes are strongly coupled by patchy plant distribution and biological soil crust (BSC) cover in plant-free interspaces. In this study, we asked: 1) how responsive are BSC cover/composition to a drying/wetting cycle and two-year grazing removal, and 2) what are the implications for soil erosion? We characterized BSC morphotypes and their influence on soil stability under grazed/non-grazed conditions during a dry and wet season. Light- and dark-colored cyanobacteria were dominant at the plant tussock and community level. Cover changes in these two groups differed after a rainy season and in response to grazing removal. Lichens with continuous thalli were more vulnerable to grazing than those with semi-continuous/discontinuous thalli after the dry season. Microsites around tussocks facilitated BSC colonization compared to interspaces. Lichen and cyanobacteria morphotypes differentially enhanced resistance to soil erosion; consequently, surface soil stability depends on the spatial distribution of BSC morphotypes, suggesting soil stability may be as dynamic as changes in the type of BSC cover. Longer-term spatially detailed studies are necessary to elicit spatiotemporal dynamics of BSC communities and their functional role in biotically and abiotically variable environments. ?? 2009 Elsevier Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Arid Environments","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jaridenv.2009.05.009","issn":"01401963","usgsCitation":"Jimenez, A.A., Huber-Sannwald, E., Belnap, J., Smart, D., and Arredondo, M.J., 2009, Biological soil crusts exhibit a dynamic response to seasonal rain and release from grazing with implications for soil stability: Journal of Arid Environments, v. 73, no. 12, p. 1158-1169, https://doi.org/10.1016/j.jaridenv.2009.05.009.","startPage":"1158","endPage":"1169","numberOfPages":"12","costCenters":[],"links":[{"id":217168,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jaridenv.2009.05.009"},{"id":245089,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"73","issue":"12","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f16ce4b0c8380cd4ac5f","contributors":{"authors":[{"text":"Jimenez, Aguilar A.","contributorId":81726,"corporation":false,"usgs":true,"family":"Jimenez","given":"Aguilar","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":459927,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Huber-Sannwald, E.","contributorId":41255,"corporation":false,"usgs":true,"family":"Huber-Sannwald","given":"E.","affiliations":[],"preferred":false,"id":459926,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Belnap, J. 0000-0001-7471-2279","orcid":"https://orcid.org/0000-0001-7471-2279","contributorId":23872,"corporation":false,"usgs":true,"family":"Belnap","given":"J.","affiliations":[],"preferred":false,"id":459924,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Smart, D.R.","contributorId":99774,"corporation":false,"usgs":true,"family":"Smart","given":"D.R.","email":"","affiliations":[],"preferred":false,"id":459928,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Arredondo, Moreno J.T.","contributorId":37573,"corporation":false,"usgs":true,"family":"Arredondo","given":"Moreno","email":"","middleInitial":"J.T.","affiliations":[],"preferred":false,"id":459925,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70037154,"text":"70037154 - 2009 - Enantiomer fractions of chlordane components in sediment from U.S. Geological Survey sites in lakes and rivers","interactions":[],"lastModifiedDate":"2018-10-05T10:10:57","indexId":"70037154","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3352,"text":"Science of the Total Environment","active":true,"publicationSubtype":{"id":10}},"title":"Enantiomer fractions of chlordane components in sediment from U.S. Geological Survey sites in lakes and rivers","docAbstract":"<p><span>Spatial, temporal, and sediment-type trends in enantiomer signatures were evaluated for&nbsp;</span><i>cis</i><span>- and&nbsp;</span><i>trans</i><span>-chlordane (CC, TC) in archived core, suspended, and surficial-sediment samples from six lake, reservoir, and river sites across the United States. The enantiomer fractions (EFs) measured in these samples are in good agreement with those reported for sediment, soil, and air samples in previous studies. The chlordane EFs were generally close to the racemic value of 0.5, with CC values ranging from 0.493 to 0.527 (usually &gt;0.5) and TC values from 0.463 to 0.53 (usually &lt;0.5). EF changes with core depth were detected for TC and CC in some cores, with the most non-racemic values near the top of the core. Surficial and suspended sediments generally have EF values similar to the top core layers but are often more non-racemic, indicating that enantioselective degradation is occurring before soils are eroded and deposited into bottom sediments. We hypothesize that rapid losses (desorption or degradation) from suspended sediments of the more bioavailable chlordane fraction during transport and initial deposition could explain the apparent shift to more racemic EF values in surficial and top core sediments. Near racemic CC and TC in the core profiles suggest minimal alteration of chlordane from biotic degradation, unless it is via non-enantioselective processes. EF values for the heptachlor degradate, heptachlor epoxide (HEPX), determined in surficial sediments from one location only were always non-racemic (EF</span><span>&nbsp;</span><span>≈</span><span>&nbsp;</span><span>0.66), were indicative of substantial biotic processing, and followed reported EF trends.</span></p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.scitotenv.2009.08.023","issn":"00489697","usgsCitation":"Ulrich, E., Foreman, W., Van Metre, P., Wilson, J., and Rounds, S., 2009, Enantiomer fractions of chlordane components in sediment from U.S. Geological Survey sites in lakes and rivers: Science of the Total Environment, v. 407, no. 22, p. 5884-5893, https://doi.org/10.1016/j.scitotenv.2009.08.023.","productDescription":"10 p.","startPage":"5884","endPage":"5893","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":245147,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":217220,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.scitotenv.2009.08.023"}],"volume":"407","issue":"22","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0919e4b0c8380cd51de2","contributors":{"authors":[{"text":"Ulrich, E.M.","contributorId":10956,"corporation":false,"usgs":true,"family":"Ulrich","given":"E.M.","email":"","affiliations":[],"preferred":false,"id":459636,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Foreman, W.T.","contributorId":94684,"corporation":false,"usgs":true,"family":"Foreman","given":"W.T.","email":"","affiliations":[],"preferred":false,"id":459639,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Van Metre, P. C.","contributorId":92999,"corporation":false,"usgs":true,"family":"Van Metre","given":"P. C.","affiliations":[],"preferred":false,"id":459638,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Wilson, J.T.","contributorId":97489,"corporation":false,"usgs":true,"family":"Wilson","given":"J.T.","affiliations":[],"preferred":false,"id":459640,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Rounds, S.A.","contributorId":88395,"corporation":false,"usgs":true,"family":"Rounds","given":"S.A.","email":"","affiliations":[],"preferred":false,"id":459637,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70037151,"text":"70037151 - 2009 - Age-distribution estimation for karst groundwater: Issues of parameterization and complexity in inverse modeling by convolution","interactions":[],"lastModifiedDate":"2012-03-12T17:22:11","indexId":"70037151","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","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":"Age-distribution estimation for karst groundwater: Issues of parameterization and complexity in inverse modeling by convolution","docAbstract":"Convolution modeling is useful for investigating the temporal distribution of groundwater age based on environmental tracers. The framework of a quasi-transient convolution model that is applicable to two-domain flow in karst aquifers is presented. The model was designed to provide an acceptable level of statistical confidence in parameter estimates when only chlorofluorocarbon (CFC) and tritium (<sup>3</sup>H) data are available. We show how inverse modeling and uncertainty assessment can be used to constrain model parameterization to a level warranted by available data while allowing major aspects of the flow system to be examined. As an example, the model was applied to water from a pumped well open to the Madison aquifer in central USA with input functions of CFC-11, CFC-12, CFC-113, and <sup>3</sup>H, and was calibrated to several samples collected during a 16-year period. A bimodal age distribution was modeled to represent quick and slow flow less than 50 years old. The effects of pumping and hydraulic head on the relative volumetric fractions of these domains were found to be influential factors for transient flow. Quick flow and slow flow were estimated to be distributed mainly within the age ranges of 0-2 and 26-41 years, respectively. The fraction of long-term flow (&gt;50 years) was estimated but was not dateable. The different tracers had different degrees of influence on parameter estimation and uncertainty assessments, where <sup>3</sup>H was the most critical, and CFC-113 was least influential.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jhydrol.2009.07.064","issn":"00221694","usgsCitation":"Long, A., and Putnam, L., 2009, Age-distribution estimation for karst groundwater: Issues of parameterization and complexity in inverse modeling by convolution: Journal of Hydrology, v. 376, no. 3-4, p. 579-588, https://doi.org/10.1016/j.jhydrol.2009.07.064.","startPage":"579","endPage":"588","numberOfPages":"10","costCenters":[],"links":[{"id":217165,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2009.07.064"},{"id":245086,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"376","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e8fde4b0c8380cd48014","contributors":{"authors":[{"text":"Long, Andrew J.","contributorId":80023,"corporation":false,"usgs":false,"family":"Long","given":"Andrew J.","affiliations":[],"preferred":false,"id":459623,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Putnam, L.D.","contributorId":47417,"corporation":false,"usgs":true,"family":"Putnam","given":"L.D.","email":"","affiliations":[],"preferred":false,"id":459622,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70037136,"text":"70037136 - 2009 - Is there evidence of adaptation to tidal flooding in saplings of baldcypress subjected to different salinity regimes?","interactions":[],"lastModifiedDate":"2019-03-27T13:40:25","indexId":"70037136","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1575,"text":"Environmental and Experimental Botany","active":true,"publicationSubtype":{"id":10}},"title":"Is there evidence of adaptation to tidal flooding in saplings of baldcypress subjected to different salinity regimes?","docAbstract":"Plant populations may adapt to environmental conditions over time by developing genetically based morphological or physiological characteristics. For tidal freshwater forested wetlands, we hypothesized that the conditions under which trees developed led to ecotypic difference in response of progeny to hydroperiod. Specifically, we looked for evidence of ecotypic adaptation for tidal flooding at different salinity regimes using growth and ecophysiological characteristics of two tidal and two non-tidal source collections of baldcypress (Taxodium distichum (L.) L.C. Rich) from the southeastern United States. Saplings were subjected to treatments of hydrology (permanent versus tidal flooding) and salinity (0 versus ???2 g l<sup>-1</sup>) for two and a half growing seasons in a greenhouse environment. Saplings from tidal sources maintained 21-41% lower overall growth and biomass accumulation than saplings from non-tidal sources, while saplings from non-tidal sources maintained 14-19% lower overall rates of net photosynthetic assimilation, leaf transpiration, and stomatal conductance than saplings from tidal sources. However, we found no evidence for growth or physiological enhancement of saplings from tidal sources to tide, or of saplings from non-tidal sources to no tide. All saplings growing under permanent flooding exhibited reduced growth and leaf gas exchange regardless of source, with little evidence for consistent salinity effects across hydroperiods. While we reject our original hypothesis, we suggest that adaptations of coastal baldcypress to broad (rather than narrow) environmental conditions may promote ecophysiological and growth enhancements under a range of global-change-induced stressors, perhaps reflecting a natural resilience to environmental change while precluding adaptations for specific flood regimes.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental and Experimental Botany","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.envexpbot.2009.05.005","issn":"00988472","usgsCitation":"Krauss, K., Doyle, T., and Howard, R., 2009, Is there evidence of adaptation to tidal flooding in saplings of baldcypress subjected to different salinity regimes?: Environmental and Experimental Botany, v. 67, no. 1, p. 118-126, https://doi.org/10.1016/j.envexpbot.2009.05.005.","startPage":"118","endPage":"126","numberOfPages":"9","costCenters":[{"id":17705,"text":"Wetland and Aquatic Research Center","active":true,"usgs":true}],"links":[{"id":245310,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":217366,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.envexpbot.2009.05.005"}],"volume":"67","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3f34e4b0c8380cd64344","contributors":{"authors":[{"text":"Krauss, K. W. 0000-0003-2195-0729","orcid":"https://orcid.org/0000-0003-2195-0729","contributorId":19517,"corporation":false,"usgs":true,"family":"Krauss","given":"K. W.","affiliations":[{"id":17705,"text":"Wetland and Aquatic Research Center","active":true,"usgs":true}],"preferred":true,"id":459546,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Doyle, T.W. 0000-0001-5754-0671","orcid":"https://orcid.org/0000-0001-5754-0671","contributorId":16783,"corporation":false,"usgs":true,"family":"Doyle","given":"T.W.","affiliations":[{"id":17705,"text":"Wetland and Aquatic Research Center","active":true,"usgs":true}],"preferred":true,"id":459545,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Howard, R.J. 0000-0001-7264-4364","orcid":"https://orcid.org/0000-0001-7264-4364","contributorId":86452,"corporation":false,"usgs":true,"family":"Howard","given":"R.J.","affiliations":[{"id":17705,"text":"Wetland and Aquatic Research Center","active":true,"usgs":true}],"preferred":false,"id":459547,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70037129,"text":"70037129 - 2009 - Fluvial fluxes of water, suspended particulate matter, and nutrients and potential impacts on tropical coastal water Biogeochemistry: Oahu, Hawai'i","interactions":[],"lastModifiedDate":"2012-03-12T17:22:10","indexId":"70037129","displayToPublicDate":"2009-01-01T00:00:00","publicationYear":"2009","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":866,"text":"Aquatic Geochemistry","active":true,"publicationSubtype":{"id":10}},"title":"Fluvial fluxes of water, suspended particulate matter, and nutrients and potential impacts on tropical coastal water Biogeochemistry: Oahu, Hawai'i","docAbstract":"Baseflow and storm runoff fluxes of water, suspended particulate matter (SPM), and nutrients (N and P) were assessed in conservation, urban, and agricultural streams discharging to coastal waters around the tropical island of Oahu, Hawai'i. Despite unusually low storm frequency and intensity during the study, storms accounted for 8-77% (median 30%) of discharge, 57-99% (median 93%) of SPM fluxes, 11-79% (median 36%) of dissolved nutrient fluxes and 52-99% (median 85%) of particulate nutrient fluxes to coastal waters. Fluvial nutrient concentrations varied with hydrologic conditions and land use; land use also affected water and particulate fluxes at some sites. Reactive dissolved N:P ratios typically were ???16 (the 'Redfield ratio' for marine phytoplankton), indicating that inputs could support new production by coastal phytoplankton, but uptake of dissolved nutrients is probably inefficient due to rapid dilution and export of fluvial dissolved inputs. Particulate N and P fluxes were similar to or larger than dissolved fluxes at all sites (median 49% of total nitrogen, range 22-82%; median 69% of total phosphorus, range 49-93%). Impacts of particulate nutrients on coastal ecosystems will depend on how efficiently SPM is retained in nearshore areas, and on the timing and degree of transformation to reactive dissolved forms. Nevertheless, the magnitude of particulate nutrient fluxes suggests that they represent a significant nutrient source for many coastal ecosystems over relatively long time scales (weeks-years), and that reductions in particulate nutrient loading actually may have negative impacts on some coastal ecosystems.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Aquatic Geochemistry","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10498-009-9067-2","issn":"13806165","usgsCitation":"Hoover, D., and MacKenzie, F., 2009, Fluvial fluxes of water, suspended particulate matter, and nutrients and potential impacts on tropical coastal water Biogeochemistry: Oahu, Hawai'i: Aquatic Geochemistry, v. 15, no. 4, p. 547-570, https://doi.org/10.1007/s10498-009-9067-2.","startPage":"547","endPage":"570","numberOfPages":"24","costCenters":[],"links":[{"id":476210,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1007/s10498-009-9067-2","text":"Publisher Index Page"},{"id":245212,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":217278,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10498-009-9067-2"}],"volume":"15","issue":"4","noUsgsAuthors":false,"publicationDate":"2009-07-28","publicationStatus":"PW","scienceBaseUri":"505a129be4b0c8380cd5438b","contributors":{"authors":[{"text":"Hoover, D.J.","contributorId":22594,"corporation":false,"usgs":true,"family":"Hoover","given":"D.J.","email":"","affiliations":[],"preferred":false,"id":459509,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"MacKenzie, F.T.","contributorId":25681,"corporation":false,"usgs":true,"family":"MacKenzie","given":"F.T.","email":"","affiliations":[],"preferred":false,"id":459510,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
]}