[1] River suspended-sediment concentrations provide insights to the erosion and transport of materials from a landscape, and changes in concentrations with time may result from landscape processes or human disturbance. Here we show that suspended-sediment concentrations in the Santa Ana River, California, decreased 20-fold with respect to discharge during a 34-year period (1968−2001). These decreases cannot be attributed to changes in sampling technique or timing, nor to event or seasonal hysteresis. Annual peak and total discharge, however, reveal sixfold increases over the 34-year record, which largely explain the decreases in sediment concentration by a nonlinear dilution process. The hydrological changes were related to the widespread urbanization of the watershed, which resulted in increases in storm water discharge without detectable alteration of sediment discharge, thus reducing suspended-sediment concentrations. Periodic upland wildfire significantly increased water discharge, sediment discharge, and suspended-sediment concentrations and thus further altered the rating curve with time. Our results suggest that previous inventories of southern California sediment flux, which assume time-constant rating curves and extend these curves beyond the sampling history, may have substantially overestimated loads during the most recent decades.
Aquatic insects often dominate lotic ecosystems, yet these organisms are under-represented in trace metal toxicity databases. Furthermore, toxicity data for aquatic insects do not appear to reflect their actual sensitivities to metals in nature, because the concentrations required to elicit toxicity in the laboratory are considerably higher than those found to impact insect communities in the field. New approaches are therefore needed to better understand how and why insects are differentially susceptible to metal exposures. Biodynamic modeling is a powerful tool for understanding interspecific differences in trace metal bioaccumulation. Because bioaccumulation alone does not necessarily correlate with toxicity, we combined biokinetic parameters associated with dissolved cadmium exposures with studies of the subcellular compartmentalization of accumulated Cd. This combination of physiological traits allowed us to make predictions of susceptibility differences to dissolved Cd in three aquatic insect taxa: Ephemerella excrucians, Rhithrogena morrisoni, and Rhyacophila sp. We compared these predictions with long-term field monitoring data and toxicity tests with closely related taxa: Ephemerella infrequens, Rhithrogena hageni, and Rhyacophila brunea. Kinetic parameters allowed us to estimate steady-state concentrations, the time required to reach steady state, and the concentrations of Cd projected to be in potentially toxic compartments for different species. Species-specific physiological traits identified using biodynamic models provided a means for better understanding why toxicity assays with insects have failed to provide meaningful estimates for metal concentrations that would be expected to be protective in nature.
A detailed local-scale monitoring network was used to assess CFC distribution in an unconfined sand aquifer in southwestern Ontario where the zone of 1–5-year-old groundwater was known with certainty because of prior use of a bromide tracer. Groundwater ⩽5 years old was confined to an aerobic zone at ⩽5 m depth and had CFC concentrations consistent with modern atmospheric mixing ratios at recharge temperatures of 7–11 °C, as was observed in the 3-m thick vadose zone at the site. At depths below 6 m, the groundwater became progressively more reducing, however, with a denitrifying horizon at 6–7 m depth, and a Mn and Fe reducing zone below 7 m depth. In the anaerobic zone, 3H/3He ratios indicated that groundwater-age continued to increase uniformly with depth, to a maximum value of 27 years at 13 m depth. CFC concentrations, however, decreased abruptly within the denitrifying zone, leading to substantial age overestimation compared to the 3H/3He ages. Noble gas data indicated that the apparent CFC mass loss was not likely the result of gas stripping from possible bubble formation; thus, CFC degradation was indicated in the anoxic zone. The field data are consistent with first-order degradation rates of 0.3 yr−1 for CFC-12, 0.7 yr−1 for CFC-11, and 1.6 yr−1 for CFC-113. CFC attenuation at this site coincides with a zone where reduced S (pyrite) is actively oxidized by NO3 and dissolved oxygen (DO). Similar behavior has been observed at other sites [Tesoriero, A.J., Liebscher, H., Cox, S.E., 2000. Mechanism and rate of denitrification in an agricultural watershed: electron and mass balance along groundwater flow path. Water Resour. Res. 36 (6), 1545–1559; Hinsby, K., Hojberg, A.L., Engesgaard, P., Jensen, K.H., Larsen, F., Plummer, L.N., Busenberg, E., Accepted for publication. Transport and degradation of chlorofluorocarbons (CFCs) in a pyritic aquifer, Rabis Creek, Denmark. Water Resour. Res.], further demonstrating that the use of CFCs for age-dating anaerobic groundwater should be approached with caution, particularly if the sediment contains pyrite.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/j.jhydrol.2007.08.009","issn":"00221694","usgsCitation":"Sebol, L., Robertson, W., Busenberg, E., Plummer, N., Ryan, M., and Schiff, S., 2007, Evidence of CFC degradation in groundwater under pyrite-oxidizing conditions: Journal of Hydrology, v. 347, no. 1-2, p. 1-12, https://doi.org/10.1016/j.jhydrol.2007.08.009.","productDescription":"12 p.","startPage":"1","endPage":"12","numberOfPages":"12","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":240537,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212965,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2007.08.009"}],"volume":"347","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0d5ce4b0c8380cd52f92","contributors":{"authors":[{"text":"Sebol, L.A.","contributorId":74204,"corporation":false,"usgs":true,"family":"Sebol","given":"L.A.","email":"","affiliations":[],"preferred":false,"id":425776,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Robertson, W.D.","contributorId":40807,"corporation":false,"usgs":true,"family":"Robertson","given":"W.D.","email":"","affiliations":[],"preferred":false,"id":425774,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Busenberg, Eurybiades ebusenbe@usgs.gov","contributorId":2271,"corporation":false,"usgs":true,"family":"Busenberg","given":"Eurybiades","email":"ebusenbe@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":425775,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Plummer, Niel 0000-0002-4020-1013 nplummer@usgs.gov","orcid":"https://orcid.org/0000-0002-4020-1013","contributorId":190100,"corporation":false,"usgs":true,"family":"Plummer","given":"Niel","email":"nplummer@usgs.gov","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":425777,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Ryan, M.C.","contributorId":105535,"corporation":false,"usgs":true,"family":"Ryan","given":"M.C.","email":"","affiliations":[],"preferred":false,"id":425778,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Schiff, S.L.","contributorId":13001,"corporation":false,"usgs":true,"family":"Schiff","given":"S.L.","email":"","affiliations":[],"preferred":false,"id":425773,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70030122,"text":"70030122 - 2007 - Quasi-horizontal circulation cells in 3D seawater intrusion","interactions":[],"lastModifiedDate":"2018-10-16T10:29:57","indexId":"70030122","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2342,"text":"Journal of Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"Quasi-horizontal circulation cells in 3D seawater intrusion","docAbstract":"The seawater intrusion process is characterized by the difference in freshwater and seawater density that causes freshwater to float on seawater. Many confined aquifers have a large horizontal extension with respect to thickness. In these cases, while buoyancy acts in the vertical direction, flow is confined between the upper and bottom boundaries and the effect of gravity is controlled by variations of aquifer elevation. Therefore, the effective gravity is controlled by the slope and the shape of the aquifer boundaries. Variability in the topography of the aquifer boundaries is one case where 3D analysis is necessary. In this work, density-dependent flow processes caused by 3D aquifer geometry are studied numerically and specifically, considering a lateral slope of the aquifer boundaries. Sub-horizontal circulation cells are formed in the saltwater entering the aquifer. The penetration of the saltwater can be quantified by a dimensionless buoyancy number that measures the lateral slope of the aquifer relative to freshwater flux. The penetration of the seawater intrusion wedge is controlled more by this slope than by the aquifer thickness and dispersivity. Thus, the slope must be taken into account in order to accurately evaluate seawater intrusion.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jhydrol.2007.02.017","issn":"00221694","usgsCitation":"Abarca, E., Carrera, J., Sanchez-Vila, X., and Voss, C.I., 2007, Quasi-horizontal circulation cells in 3D seawater intrusion: Journal of Hydrology, v. 339, no. 3-4, p. 118-129, https://doi.org/10.1016/j.jhydrol.2007.02.017.","productDescription":"12 p.","startPage":"118","endPage":"129","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":477026,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://www.scipedia.com/public/Abarca_et_al_2007b","text":"External Repository"},{"id":213020,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2007.02.017"},{"id":240600,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"339","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a9279e4b0c8380cd80894","contributors":{"authors":[{"text":"Abarca, E.","contributorId":28077,"corporation":false,"usgs":true,"family":"Abarca","given":"E.","affiliations":[],"preferred":false,"id":425806,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Carrera, J.","contributorId":68536,"corporation":false,"usgs":true,"family":"Carrera","given":"J.","email":"","affiliations":[],"preferred":false,"id":425807,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sanchez-Vila, X.","contributorId":106716,"corporation":false,"usgs":true,"family":"Sanchez-Vila","given":"X.","email":"","affiliations":[],"preferred":false,"id":425809,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Voss, Clifford I. 0000-0001-5923-2752 cvoss@usgs.gov","orcid":"https://orcid.org/0000-0001-5923-2752","contributorId":1559,"corporation":false,"usgs":true,"family":"Voss","given":"Clifford","email":"cvoss@usgs.gov","middleInitial":"I.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":425808,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}} ,{"id":70030130,"text":"70030130 - 2007 - Ground water stratification and delivery of nitrate to an incised stream under varying flow conditions","interactions":[],"lastModifiedDate":"2018-10-17T08:52:23","indexId":"70030130","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2262,"text":"Journal of Environmental Quality","active":true,"publicationSubtype":{"id":10}},"title":"Ground water stratification and delivery of nitrate to an incised stream under varying flow conditions","docAbstract":"Ground water processes affecting seasonal variations of surface water nitrate concentrations were investigated in an incised first-order stream in an agricultural watershed with a riparian forest in the coastal plain of Maryland. Aquifer characteristics including sediment stratigraphy, geochemistry, and hydraulic properties were examined in combination with chemical and isotopic analyses of ground water, macropore discharge, and stream water. The ground water flow system exhibits vertical stratification of hydraulic properties and redox conditions, with sub-horizontal boundaries that extend beneath the field and adjacent riparian forest. Below the minimum water table position, ground water age gradients indicate low recharge rates (2-5 cm yr-1) and long residence times (years to decades), whereas the transient ground water wedge between the maximum and minimum water table positions has a relatively short residence time (months to years), partly because of an upward increase in hydraulic conductivity. Oxygen reduction and denitrification in recharging ground waters are coupled with pyrite oxidation near the minimum water table elevation in a mottled weathering zone in Tertiary marine glauconitic sediments. The incised stream had high nitrate concentrations during high flow conditions when much of the ground water was transmitted rapidly across the riparian zone in a shallow oxic aquifer wedge with abundant outflow macropores, and low nitrate concentrations during low flow conditions when the oxic wedge was smaller and stream discharge was dominated by upwelling from the deeper denitrified parts of the aquifer. Results from this and similar studies illustrate the importance of near-stream geomorphology and subsurface geology as controls of riparian zone function and delivery of nitrate to streams in agricultural watersheds.
","language":"English","publisher":"ACSESS","doi":"10.2134/jeq2006.0084","issn":"00472425","usgsCitation":"Bohlke, J.K., O’Connell, M.E., and Prestegaard, K., 2007, Ground water stratification and delivery of nitrate to an incised stream under varying flow conditions: Journal of Environmental Quality, v. 36, no. 3, p. 664-680, https://doi.org/10.2134/jeq2006.0084.","productDescription":"17 p.","startPage":"664","endPage":"680","numberOfPages":"17","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":240699,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213108,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2134/jeq2006.0084"}],"country":"United States","state":"Maryland","volume":"36","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2b27e4b0c8380cd5b745","contributors":{"authors":[{"text":"Bohlke, John Karl 0000-0001-5693-6455 jkbohlke@usgs.gov","orcid":"https://orcid.org/0000-0001-5693-6455","contributorId":127841,"corporation":false,"usgs":true,"family":"Bohlke","given":"John","email":"jkbohlke@usgs.gov","middleInitial":"Karl","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":false,"id":425834,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"O’Connell, M. E.","contributorId":64033,"corporation":false,"usgs":true,"family":"O’Connell","given":"M.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":425833,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Prestegaard, K.L.","contributorId":51545,"corporation":false,"usgs":true,"family":"Prestegaard","given":"K.L.","email":"","affiliations":[],"preferred":false,"id":425832,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030131,"text":"70030131 - 2007 - The chemical response of particle-associated contaminants in aquatic sediments to urbanization in New England, U.S.A.","interactions":[],"lastModifiedDate":"2012-03-12T17:21:06","indexId":"70030131","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2233,"text":"Journal of Contaminant Hydrology","active":true,"publicationSubtype":{"id":10}},"title":"The chemical response of particle-associated contaminants in aquatic sediments to urbanization in New England, U.S.A.","docAbstract":"Relations between urbanization and particle-associated contaminants in New England were evaluated using a combination of samples from sediment cores, streambed sediments, and suspended stream sediments. Concentrations of PAHs, PCBs, DDT, and seven trace metals (Cd, Cr, Cu, Hg, Ni, Pb, Zn) were correlated strongly with urbanization, with the strongest relations to percentage commercial, industrial, and transportation (CIT) land use. Average PAH and metal concentrations in the most urbanized watersheds were approximately 30 and 6 times the reference concentrations, respectively, in remote, undeveloped watersheds. One-quarter to one-half of sampling sites had concentrations of PAHs, Cu, Pb, or Zn above the probable effects concentration, a set of sediment quality guidelines for adverse effects to aquatic biota, and sediments were predicted to be toxic, on average, when CIT land use exceeded about 10%. Trends in metals in cores from urban watersheds were dominantly downward, whereas trends in PAHs in a suburban watershed were upward. A regional atmospheric-fallout gradient was indicated by as much as order-of-magnitude-greater concentrations and accumulation rates of contaminants in cores from an undeveloped reference lake in Boston compared to those from remote reference watersheds. Contaminant accumulation rates in the lakes with urbanization in their watersheds, however, were 1-3 orders of magnitude greater than those of reference lakes, which indicate the dominance of local sources and fluvial transport of contaminants to urban lakes. These analyses demonstrate the magnitude of urban contamination of aquatic systems and air sheds, and suggest that, despite reductions in contaminant emissions in urban settings, streams and lakes will decline in quality as urbanization of their watersheds takes place. ?? 2006 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Contaminant Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jconhyd.2006.08.007","issn":"01697722","usgsCitation":"Chalmers, A., Van Metre, P., and Callender, E., 2007, The chemical response of particle-associated contaminants in aquatic sediments to urbanization in New England, U.S.A.: Journal of Contaminant Hydrology, v. 91, no. 1-2, p. 4-25, https://doi.org/10.1016/j.jconhyd.2006.08.007.","startPage":"4","endPage":"25","numberOfPages":"22","costCenters":[],"links":[{"id":212672,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jconhyd.2006.08.007"},{"id":240195,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"91","issue":"1-2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505baa2de4b08c986b32274a","contributors":{"authors":[{"text":"Chalmers, A.T. 0000-0002-5199-8080","orcid":"https://orcid.org/0000-0002-5199-8080","contributorId":63576,"corporation":false,"usgs":true,"family":"Chalmers","given":"A.T.","affiliations":[],"preferred":false,"id":425835,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Van Metre, P. C.","contributorId":92999,"corporation":false,"usgs":true,"family":"Van Metre","given":"P. C.","affiliations":[],"preferred":false,"id":425837,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Callender, E.","contributorId":72528,"corporation":false,"usgs":true,"family":"Callender","given":"E.","email":"","affiliations":[],"preferred":false,"id":425836,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030134,"text":"70030134 - 2007 - Groundwater flow with energy transport and water-ice phase change: Numerical simulations, benchmarks, and application to freezing in peat bogs","interactions":[],"lastModifiedDate":"2018-10-17T09:03:27","indexId":"70030134","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":664,"text":"Advances in Water Resources","active":true,"publicationSubtype":{"id":10}},"title":"Groundwater flow with energy transport and water-ice phase change: Numerical simulations, benchmarks, and application to freezing in peat bogs","docAbstract":"In northern peatlands, subsurface ice formation is an important process that can control heat transport, groundwater flow, and biological activity. Temperature was measured over one and a half years in a vertical profile in the Red Lake Bog, Minnesota. To successfully simulate the transport of heat within the peat profile, the U.S. Geological Survey's SUTRA computer code was modified. The modified code simulates fully saturated, coupled porewater-energy transport, with freezing and melting porewater, and includes proportional heat capacity and thermal conductivity of water and ice, decreasing matrix permeability due to ice formation, and latent heat. The model is verified by correctly simulating the Lunardini analytical solution for ice formation in a porous medium with a mixed ice-water zone. The modified SUTRA model correctly simulates the temperature and ice distributions in the peat bog. Two possible benchmark problems for groundwater and energy transport with ice formation and melting are proposed that may be used by other researchers for code comparison.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Advances in Water Resources","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/j.advwatres.2006.08.008","issn":"03091708","usgsCitation":"McKenzie, J., Voss, C.I., and Siegel, D.I., 2007, Groundwater flow with energy transport and water-ice phase change: Numerical simulations, benchmarks, and application to freezing in peat bogs: Advances in Water Resources, v. 30, no. 4, p. 966-983, https://doi.org/10.1016/j.advwatres.2006.08.008.","productDescription":"18 p.","startPage":"966","endPage":"983","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":240262,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212730,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.advwatres.2006.08.008"}],"country":"United States","state":"Minnesota","otherGeospatial":"Red Lake Bog","volume":"30","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a2da2e4b0c8380cd5bf70","contributors":{"authors":[{"text":"McKenzie, J.M.","contributorId":75759,"corporation":false,"usgs":true,"family":"McKenzie","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":425843,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Voss, Clifford I. 0000-0001-5923-2752 cvoss@usgs.gov","orcid":"https://orcid.org/0000-0001-5923-2752","contributorId":1559,"corporation":false,"usgs":true,"family":"Voss","given":"Clifford","email":"cvoss@usgs.gov","middleInitial":"I.","affiliations":[{"id":438,"text":"National Research Program - Western Branch","active":true,"usgs":true}],"preferred":true,"id":425845,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Siegel, D. I.","contributorId":77562,"corporation":false,"usgs":true,"family":"Siegel","given":"D.","email":"","middleInitial":"I.","affiliations":[],"preferred":false,"id":425844,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030154,"text":"70030154 - 2007 - Reconstructing sediment age profiles from historical bathymetry changes in San Pablo Bay, California","interactions":[],"lastModifiedDate":"2023-08-09T11:31:02.587934","indexId":"70030154","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1587,"text":"Estuarine, Coastal and Shelf Science","active":true,"publicationSubtype":{"id":10}},"title":"Reconstructing sediment age profiles from historical bathymetry changes in San Pablo Bay, California","docAbstract":"Sediment age profiles reconstructed from a sequence of historical bathymetry changes are used to investigate the subsurface distribution of historical sediments in a subembayment of the San Francisco Estuary. Profiles are created in a grid-based GIS modeling program that stratifies historical deposition into temporal horizons. The model's reconstructions are supported by comparisons to profiles of 137Cs and excess 210Pb at 12 core sites. The predicted depth of the 1951 sediment horizon is positively correlated to the depth of the first occurrence of 137Cs at sites that have been depositional between recent surveys. Reconstructions at sites that have been erosional since the 1951 survey are supported by a lack of detectable 137Cs and excess 210Pb below the upper 6–16 cm of the core. A new data set of predicted near-surface sediment ages was created to illustrate an application of this approach. Results demonstrate other potential applications such as guiding the spatial positioning of future core sites for contaminant measurements.
This paper describes the application of remotely sensed precipitation to the monitoring of floods in a region that regularly experiences extreme precipitation and flood events, often associated with cyclonic systems. Precipitation data, which are derived from spaceborne radar aboard the National Aeronautics and Space Administration's Tropical Rainfall Measuring Mission and from National Oceanic and Atmospheric Administration's infrared-based products, are used to monitor areas experiencing extreme precipitation events that are defined as exceedance of a daily mean areal average value of 50 mm over a catchment. The remotely sensed precipitation data are also ingested into a hydrologic model that is parameterized using spatially distributed elevation, soil, and land cover data sets that are available globally from remote sensing and in situ sources. The resulting stream-flow is classified as an extreme flood event when flow anomalies exceed 1.5 standard deviations above the short-term mean. In an application in the Limpopo basin, it is demonstrated that the use of satellite-derived precipitation allows for the identification of extreme precipitation and flood events, both in terms of relative intensity and spatial extent. The system is used by water authorities in Mozambique to proactively initiate independent flood hazard verification before generating flood warnings. The system also serves as a supplementary information source when in situ gauging systems are disrupted. This paper concludes that remotely sensed precipitation and derived products greatly enhance the ability of water managers in the Limpopo basin to monitor extreme flood events and provide at-risk communities with early warning information. ?? 2007 IEEE.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"IEEE Transactions on Geoscience and Remote Sensing","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1109/TGRS.2006.883147","issn":"01962892","usgsCitation":"Asante, K., Macuacua, R., Artan, G.A., Lietzow, R., and Verdin, J., 2007, Developing a flood monitoring system from remotely sensed data for the Limpopo basin: IEEE Transactions on Geoscience and Remote Sensing, v. 45, no. 6, p. 1709-1714, https://doi.org/10.1109/TGRS.2006.883147.","startPage":"1709","endPage":"1714","numberOfPages":"6","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":222,"text":"Earth Resources Observation and Science (EROS) Center","active":true,"usgs":true}],"links":[{"id":240635,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":213054,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1109/TGRS.2006.883147"}],"country":"South Africa","otherGeospatial":"Limpopo River","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n \"geometry\": {\n \"type\": \"Polygon\",\n \"coordinates\": [\n [\n [\n 25.6640625,\n -25.641526373065755\n ],\n [\n 25.6640625,\n -22.06527806776582\n ],\n [\n 33.0029296875,\n -22.06527806776582\n ],\n [\n 33.0029296875,\n -25.641526373065755\n ],\n [\n 25.6640625,\n -25.641526373065755\n ]\n ]\n ]\n }\n }\n ]\n}","volume":"45","issue":"6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0009e4b0c8380cd4f553","contributors":{"authors":[{"text":"Asante, K.O. 0000-0001-5408-1852","orcid":"https://orcid.org/0000-0001-5408-1852","contributorId":17051,"corporation":false,"usgs":true,"family":"Asante","given":"K.O.","affiliations":[],"preferred":false,"id":425935,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Macuacua, R.D.","contributorId":22585,"corporation":false,"usgs":true,"family":"Macuacua","given":"R.D.","email":"","affiliations":[],"preferred":false,"id":425936,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Artan, G. A.","contributorId":50733,"corporation":false,"usgs":false,"family":"Artan","given":"G.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":425938,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Lietzow, R.W.","contributorId":58104,"corporation":false,"usgs":true,"family":"Lietzow","given":"R.W.","email":"","affiliations":[],"preferred":false,"id":425939,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Verdin, J. P. 0000-0003-0238-9657","orcid":"https://orcid.org/0000-0003-0238-9657","contributorId":33033,"corporation":false,"usgs":true,"family":"Verdin","given":"J. P.","affiliations":[],"preferred":false,"id":425937,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70030175,"text":"70030175 - 2007 - The collapse of pelagic fishes in the upper San Francisco estuary","interactions":[],"lastModifiedDate":"2021-03-30T14:40:57.645549","indexId":"70030175","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1657,"text":"Fisheries","onlineIssn":"1548-8446","printIssn":"0363-2415","active":true,"publicationSubtype":{"id":10}},"title":"The collapse of pelagic fishes in the upper San Francisco estuary","docAbstract":"Although the pelagic fish community of the upper San Francisco Estuary historically has shown substantial variability, a recent collapse has captured the attention of resource managers, scientists, legislators, and the general public. The ecological and management consequences of the decline are most serious for delta smelt (Hypomesus transpacificus), a threatened species whose narrow range overlaps with large water diversions that supply water to over 25 million people. The decline occurred despite recent moderate hydrology, which typically results in at least modest recruitment, and investments of hundreds of millions of dollars in habitat restoration and environmental water allocations to support native fishes. In response to the pelagic fish collapse, an ambitious multi-hyphen;agency research team has been working since 2005 to evaluate the causes of the decline, which likely include a combination of factors: stock-recruitment effects, a decline in habitat quality, increased mortality rates, and reduced food availability due to invasive species.
","language":"English","publisher":"Taylor & Francis","doi":"10.1577/1548-8446(2007)32[270:TCOPFI]2.0.CO;2","usgsCitation":"Sommer, T., Armor, C., Baxter, R., Breuer, R., Brown, L., Chotkowski, M., Culberson, S., Feyrer, F., Gingras, M., Herbold, B., Kimmerer, W., Mueller-Solger, A., Nobriga, M., and Souza, K., 2007, The collapse of pelagic fishes in the upper San Francisco estuary: Fisheries, v. 32, no. 6, p. 270-277, https://doi.org/10.1577/1548-8446(2007)32[270:TCOPFI]2.0.CO;2.","productDescription":"8 p.","startPage":"270","endPage":"277","costCenters":[{"id":154,"text":"California Water Science Center","active":true,"usgs":true}],"links":[{"id":239257,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"California","otherGeospatial":"Upper San Francisco Estuary","geographicExtents":"{\n \"type\": \"FeatureCollection\",\n \"features\": [\n {\n \"type\": \"Feature\",\n \"properties\": {},\n 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T.","contributorId":106703,"corporation":false,"usgs":true,"family":"Sommer","given":"T.","email":"","affiliations":[],"preferred":false,"id":426015,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Armor, C.","contributorId":76942,"corporation":false,"usgs":true,"family":"Armor","given":"C.","email":"","affiliations":[],"preferred":false,"id":426011,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Baxter, R.","contributorId":48758,"corporation":false,"usgs":true,"family":"Baxter","given":"R.","email":"","affiliations":[],"preferred":false,"id":426006,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Breuer, R.","contributorId":16219,"corporation":false,"usgs":true,"family":"Breuer","given":"R.","email":"","affiliations":[],"preferred":false,"id":426003,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Brown, L. 0000-0001-6702-4531","orcid":"https://orcid.org/0000-0001-6702-4531","contributorId":56995,"corporation":false,"usgs":true,"family":"Brown","given":"L.","affiliations":[],"preferred":false,"id":426007,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Chotkowski, M.","contributorId":78543,"corporation":false,"usgs":true,"family":"Chotkowski","given":"M.","affiliations":[],"preferred":false,"id":426012,"contributorType":{"id":1,"text":"Authors"},"rank":6},{"text":"Culberson, S.","contributorId":96480,"corporation":false,"usgs":true,"family":"Culberson","given":"S.","affiliations":[],"preferred":false,"id":426014,"contributorType":{"id":1,"text":"Authors"},"rank":7},{"text":"Feyrer, F. 0000-0003-1253-2349","orcid":"https://orcid.org/0000-0003-1253-2349","contributorId":6254,"corporation":false,"usgs":true,"family":"Feyrer","given":"F.","affiliations":[],"preferred":false,"id":426002,"contributorType":{"id":1,"text":"Authors"},"rank":8},{"text":"Gingras, M.","contributorId":58093,"corporation":false,"usgs":true,"family":"Gingras","given":"M.","affiliations":[],"preferred":false,"id":426008,"contributorType":{"id":1,"text":"Authors"},"rank":9},{"text":"Herbold, B.","contributorId":66062,"corporation":false,"usgs":true,"family":"Herbold","given":"B.","affiliations":[],"preferred":false,"id":426009,"contributorType":{"id":1,"text":"Authors"},"rank":10},{"text":"Kimmerer, W.","contributorId":38325,"corporation":false,"usgs":false,"family":"Kimmerer","given":"W.","email":"","affiliations":[],"preferred":false,"id":426005,"contributorType":{"id":1,"text":"Authors"},"rank":11},{"text":"Mueller-Solger, A.","contributorId":16220,"corporation":false,"usgs":true,"family":"Mueller-Solger","given":"A.","affiliations":[],"preferred":false,"id":426004,"contributorType":{"id":1,"text":"Authors"},"rank":12},{"text":"Nobriga, M.","contributorId":67284,"corporation":false,"usgs":true,"family":"Nobriga","given":"M.","affiliations":[],"preferred":false,"id":426010,"contributorType":{"id":1,"text":"Authors"},"rank":13},{"text":"Souza, K.","contributorId":84157,"corporation":false,"usgs":true,"family":"Souza","given":"K.","email":"","affiliations":[],"preferred":false,"id":426013,"contributorType":{"id":1,"text":"Authors"},"rank":14}]}} ,{"id":70030183,"text":"70030183 - 2007 - A classification of U.S. estuaries based on physical and hydrologic attributes","interactions":[],"lastModifiedDate":"2012-03-12T17:21:01","indexId":"70030183","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1552,"text":"Environmental Monitoring and Assessment","onlineIssn":"1573-2959","printIssn":"0167-6369","active":true,"publicationSubtype":{"id":10}},"title":"A classification of U.S. estuaries based on physical and hydrologic attributes","docAbstract":"A classification of U.S. estuaries is presented based on estuarine characteristics that have been identified as important for quantifying stressor-response relationships in coastal systems. Estuaries within a class have similar physical and hydrologic characteristics and would be expected to demonstrate similar biological responses to stressor loads from the adjacent watersheds. Nine classes of estuaries were identified by applying cluster analysis to a database for 138 U.S. estuarine drainage areas. The database included physical measures of estuarine areas, depth and volume, as well as hydrologic parameters (i.e., tide height, tidal prism volume, freshwater inflow rates, salinity, and temperature). The ability of an estuary to dilute or flush pollutants can be estimated using physical and hydrologic properties such as volume, bathymetry, freshwater inflow and tidal exchange rates which influence residence time and affect pollutant loading rates. Thus, physical and hydrologic characteristics can be used to estimate the susceptibility of estuaries to pollutant effects. This classification of estuaries can be used by natural resource managers to describe and inventory coastal systems, understand stressor impacts, predict which systems are most sensitive to stressors, and manage and protect coastal resources. ?? Springer Science+Business Media B.V. 2007.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Environmental Monitoring and Assessment","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1007/s10661-006-9372-9","issn":"01676369","usgsCitation":"Engle, V., Kurtz, J., Smith, L., Chancy, C., and Bourgeois, P., 2007, A classification of U.S. estuaries based on physical and hydrologic attributes: Environmental Monitoring and Assessment, v. 129, no. 1-3, p. 397-412, https://doi.org/10.1007/s10661-006-9372-9.","startPage":"397","endPage":"412","numberOfPages":"16","costCenters":[],"links":[{"id":211995,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1007/s10661-006-9372-9"},{"id":239392,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"129","issue":"1-3","noUsgsAuthors":false,"publicationDate":"2007-02-03","publicationStatus":"PW","scienceBaseUri":"5059e342e4b0c8380cd45ef6","contributors":{"authors":[{"text":"Engle, V.D.","contributorId":15562,"corporation":false,"usgs":true,"family":"Engle","given":"V.D.","email":"","affiliations":[],"preferred":false,"id":426051,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Kurtz, J.C.","contributorId":63616,"corporation":false,"usgs":true,"family":"Kurtz","given":"J.C.","email":"","affiliations":[],"preferred":false,"id":426052,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Smith, L.M.","contributorId":82650,"corporation":false,"usgs":true,"family":"Smith","given":"L.M.","email":"","affiliations":[],"preferred":false,"id":426054,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Chancy, C.","contributorId":72202,"corporation":false,"usgs":true,"family":"Chancy","given":"C.","email":"","affiliations":[],"preferred":false,"id":426053,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Bourgeois, P.","contributorId":94498,"corporation":false,"usgs":true,"family":"Bourgeois","given":"P.","affiliations":[],"preferred":false,"id":426055,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}} ,{"id":70030186,"text":"70030186 - 2007 - Potential effects of regional pumpage on groundwater age distribution","interactions":[],"lastModifiedDate":"2018-10-11T19:04:32","indexId":"70030186","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Potential effects of regional pumpage on groundwater age distribution","docAbstract":"Groundwater ages estimated from environmental tracers can help calibrate groundwater flow models. Groundwater age represents a mixture of traveltimes, with the distribution of ages determined by the detailed structure of the flow field, which can be prone to significant transient variability. Effects of pumping on age distribution were assessed using direct age simulation in a hypothetical layered aquifer system. A steady state predevelopment age distribution was computed first. A well field was then introduced, and pumpage caused leakage into the confined aquifer of older water from an overlying confining unit. Large changes in simulated groundwater ages occurred in both the aquifer and the confining unit at high pumping rates, and the effects propagated a substantial distance downgradient from the wells. The range and variance of ages contributing to the well increased substantially during pumping. The results suggest that the groundwater age distribution in developed aquifers may be affected by transient leakage from low‐permeability material, such as confining units, under certain hydrogeologic conditions.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2006WR004865","usgsCitation":"Zinn, B.A., and Konikow, L.F., 2007, Potential effects of regional pumpage on groundwater age distribution: Water Resources Research, v. 43, no. 6, W06418; 17 p., https://doi.org/10.1029/2006WR004865.","productDescription":"W06418; 17 p.","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":477032,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2006wr004865","text":"Publisher Index Page"},{"id":239431,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"43","issue":"6","noUsgsAuthors":false,"publicationDate":"2007-06-21","publicationStatus":"PW","scienceBaseUri":"505a7edde4b0c8380cd7a7c9","contributors":{"authors":[{"text":"Zinn, Brendan A.","contributorId":102953,"corporation":false,"usgs":true,"family":"Zinn","given":"Brendan","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":426060,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Konikow, Leonard F. 0000-0002-0940-3856 lkonikow@usgs.gov","orcid":"https://orcid.org/0000-0002-0940-3856","contributorId":158,"corporation":false,"usgs":true,"family":"Konikow","given":"Leonard","email":"lkonikow@usgs.gov","middleInitial":"F.","affiliations":[{"id":436,"text":"National Research Program - Eastern Branch","active":true,"usgs":true}],"preferred":true,"id":426059,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70030188,"text":"70030188 - 2007 - Urbanization and nutrient retention in freshwater riparian wetlands","interactions":[],"lastModifiedDate":"2012-03-12T17:21:01","indexId":"70030188","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1450,"text":"Ecological Applications","active":true,"publicationSubtype":{"id":10}},"title":"Urbanization and nutrient retention in freshwater riparian wetlands","docAbstract":"Urbanization can degrade water quality and alter watershed hydrology, with profound effects on the structure and function of both riparian wetlands (RWs) and aquatic ecosystems downstream. We used freshwater RWs in Fairfax County, Virginia, USA, as a model system to examine: (1) the effects of increasing urbanization (indexed by the percentage of impervious surface cover [%ISC] in the surrounding watershed) on nitrogen (N) and phosphorus (P) concentrations in surface soils and plant tissues, soil P saturation, and soil iron (Fe) chemistry; and (2) relationships between RW soil and plant nutrient chemistries vs. the physical and biotic integrity of adjacent streams. Soil total P and NaOH-extractable P (representing P bound to aluminum [Al] and Fe hydrous oxides) varied significantly but nonlinearly with %ISC (r2 = 0.69 and 0.57, respectively); a similar pattern was found for soil P saturation but not for soil total N. Relationships were best described by second-order polynomial equations. Riparian wetlands appear to receive greater P loads in moderately (8.6-13.3% ISC) than in highly (25.1-29.1% ISC) urbanized watersheds. These observations are consistent with alterations in watershed hydrology that occur with increasing urbanization, directing water and nutrient flows away from natural RWs. Significant increases in total and crystalline soil Fe (r 2 = 0.57 and 0.53, respectively) and decreases in relative soil Fe crystallinity with increasing %ISC suggest the mobilization and deposition of terrestrial sediments in RWs, likely due to construction activities in the surrounding watershed. Increases in RW plant tissue nutrient concentrations and %ISC in the surrounding watershed were negatively correlated with standard indices of the physical and biotic integrity of adjacent streams. In combination, these data suggest that nutrient and sediment inputs associated with urbanization and storm-water management are important variables that affect wetland ecosystem services, such as water quality improvement, in urbanizing landscapes. ?? 2007 by the Ecological Society of America.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Ecological Applications","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1890/06-0185","issn":"10510761","usgsCitation":"Hogan, D., and Walbridge, M., 2007, Urbanization and nutrient retention in freshwater riparian wetlands: Ecological Applications, v. 17, no. 4, p. 1142-1155, https://doi.org/10.1890/06-0185.","startPage":"1142","endPage":"1155","numberOfPages":"14","costCenters":[],"links":[{"id":212057,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1890/06-0185"},{"id":239468,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"17","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bbe40e4b08c986b3294a6","contributors":{"authors":[{"text":"Hogan, D.M.","contributorId":106711,"corporation":false,"usgs":true,"family":"Hogan","given":"D.M.","email":"","affiliations":[],"preferred":false,"id":426065,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Walbridge, M.R.","contributorId":80488,"corporation":false,"usgs":true,"family":"Walbridge","given":"M.R.","email":"","affiliations":[],"preferred":false,"id":426064,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70030196,"text":"70030196 - 2007 - Groundwater noble gas, age, and temperature signatures in an Alpine watershed: Valuable tools in conceptual model development","interactions":[],"lastModifiedDate":"2018-04-03T13:21:21","indexId":"70030196","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Groundwater noble gas, age, and temperature signatures in an Alpine watershed: Valuable tools in conceptual model development","docAbstract":"Bedrock groundwater in alpine watersheds is poorly understood, mainly because of a scarcity of wells in alpine settings. Groundwater noble gas, age, and temperature data were collected from springs and wells with depths of 3–342 m in Handcart Gulch, an alpine watershed in Colorado. Temperature profiles indicate active groundwater circulation to a maximum depth (aquifer thickness) of about 200 m, or about 150 m below the water table. Dissolved noble gas data show unusually high excess air concentrations (>0.02 cm3 STP/g, ΔNe > 170%) in the bedrock, consistent with unusually large seasonal water table fluctuations (up to 50 m) observed in the upper part of the watershed. Apparent 3H/3He ages are positively correlated with sample depth and excess air concentrations. Integrated samples were collected from artesian bedrock wells near the trunk stream and are assumed to approximate flow‐weighted samples reflecting bedrock aquifer mean residence times. Exponential mean ages for these integrated samples are remarkably consistent along the stream, four of five being from 8 to 11 years. The tracer data in combination with other hydrologic and geologic data support a relatively simple conceptual model of groundwater flow in the watershed in which (1) permeability is primarily a function of depth; (2) water table fluctuations increase with distance from the stream; and (3) recharge, aquifer thickness, and porosity are relatively uniform throughout the watershed in spite of the geological complexity of the Proterozoic crystalline rocks that underlie it.
","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2006WR005349","usgsCitation":"Manning, A.H., and Caine, J.S., 2007, Groundwater noble gas, age, and temperature signatures in an Alpine watershed: Valuable tools in conceptual model development: Water Resources Research, v. 43, no. 4, Article W04404; 16 p., https://doi.org/10.1029/2006WR005349.","productDescription":"Article W04404; 16 p.","costCenters":[],"links":[{"id":477130,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2006wr005349","text":"Publisher Index Page"},{"id":239611,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"43","issue":"4","noUsgsAuthors":false,"publicationDate":"2007-04-04","publicationStatus":"PW","scienceBaseUri":"505a2dabe4b0c8380cd5bf9a","contributors":{"authors":[{"text":"Manning, Andrew H. 0000-0002-6404-1237 amanning@usgs.gov","orcid":"https://orcid.org/0000-0002-6404-1237","contributorId":1305,"corporation":false,"usgs":true,"family":"Manning","given":"Andrew","email":"amanning@usgs.gov","middleInitial":"H.","affiliations":[{"id":171,"text":"Central Mineral and Environmental Resources Science Center","active":true,"usgs":true}],"preferred":true,"id":426091,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Caine, Jonathan S. 0000-0002-7269-6989 jscaine@usgs.gov","orcid":"https://orcid.org/0000-0002-7269-6989","contributorId":1272,"corporation":false,"usgs":true,"family":"Caine","given":"Jonathan","email":"jscaine@usgs.gov","middleInitial":"S.","affiliations":[{"id":211,"text":"Crustal Geophysics and Geochemistry Science Center","active":true,"usgs":true}],"preferred":false,"id":426092,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70030208,"text":"70030208 - 2007 - Efficiency of conventional drinking-water-treatment processes in removal of pharmaceuticals and other organic compounds","interactions":[],"lastModifiedDate":"2018-10-17T10:52:39","indexId":"70030208","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","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":"Efficiency of conventional drinking-water-treatment processes in removal of pharmaceuticals and other organic compounds","docAbstract":"Samples of water and sediment from a conventional drinking-water-treatment (DWT) plant were analyzed for 113 organic compounds (OCs) that included pharmaceuticals, detergent degradates, flame retardants and plasticizers, polycyclic aromatic hydrocarbons (PAHs), fragrances and flavorants, pesticides and an insect repellent, and plant and animal steroids. 45 of these compounds were detected in samples of source water and 34 were detected in samples of settled sludge and (or) filter-backwash sediments. The average percent removal of these compounds was calculated from their average concentration in time-composited water samples collected after clarification, disinfection (chlorination), and granular-activated-carbon (GAC) filtration. In general, GAC filtration accounted for 53% of the removal of these compounds from the aqueous phase; disinfection accounted for 32%, and clarification accounted for 15%. The effectiveness of these treatments varied widely within and among classes of compounds; some hydrophobic compounds were strongly oxidized by free chlorine, and some hydrophilic compounds were partly removed through adsorption processes. The detection of 21 of the compounds in 1 or more samples of finished water, and of 3 to 13 compounds in every finished-water sample, indicates substantial but incomplete degradation or removal of OCs through the conventional DWT process used at this plant.
","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Science of the Total Environment","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Elsevier","doi":"10.1016/j.scitotenv.2007.01.095","issn":"00489697","usgsCitation":"Stackelberg, P.E., Gibs, J., Furlong, E.T., Meyer, M.T., Zaugg, S.D., and Lippincott, R., 2007, Efficiency of conventional drinking-water-treatment processes in removal of pharmaceuticals and other organic compounds: Science of the Total Environment, v. 377, no. 2-3, p. 255-272, https://doi.org/10.1016/j.scitotenv.2007.01.095.","productDescription":"18 p.","startPage":"255","endPage":"272","numberOfPages":"18","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":239258,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211884,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.scitotenv.2007.01.095"}],"volume":"377","issue":"2-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0866e4b0c8380cd51adb","contributors":{"authors":[{"text":"Stackelberg, Paul E. 0000-0002-1818-355X pestack@usgs.gov","orcid":"https://orcid.org/0000-0002-1818-355X","contributorId":1069,"corporation":false,"usgs":true,"family":"Stackelberg","given":"Paul","email":"pestack@usgs.gov","middleInitial":"E.","affiliations":[{"id":474,"text":"New York Water Science Center","active":true,"usgs":true}],"preferred":true,"id":426129,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gibs, Jacob jgibs@usgs.gov","contributorId":1729,"corporation":false,"usgs":true,"family":"Gibs","given":"Jacob","email":"jgibs@usgs.gov","affiliations":[],"preferred":true,"id":426132,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Furlong, Edward T. 0000-0002-7305-4603 efurlong@usgs.gov","orcid":"https://orcid.org/0000-0002-7305-4603","contributorId":740,"corporation":false,"usgs":true,"family":"Furlong","given":"Edward","email":"efurlong@usgs.gov","middleInitial":"T.","affiliations":[{"id":503,"text":"Office of Water Quality","active":true,"usgs":true},{"id":5046,"text":"Branch of Analytical Serv (NWQL)","active":true,"usgs":true},{"id":27111,"text":"National Water Quality Program","active":true,"usgs":true},{"id":191,"text":"Colorado Water Science Center","active":true,"usgs":true}],"preferred":true,"id":426134,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Meyer, Michael T. 0000-0001-6006-7985 mmeyer@usgs.gov","orcid":"https://orcid.org/0000-0001-6006-7985","contributorId":866,"corporation":false,"usgs":true,"family":"Meyer","given":"Michael","email":"mmeyer@usgs.gov","middleInitial":"T.","affiliations":[{"id":353,"text":"Kansas Water Science Center","active":false,"usgs":true}],"preferred":true,"id":426133,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Zaugg, Steven D. sdzaugg@usgs.gov","contributorId":768,"corporation":false,"usgs":true,"family":"Zaugg","given":"Steven","email":"sdzaugg@usgs.gov","middleInitial":"D.","affiliations":[],"preferred":true,"id":426131,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Lippincott, R.L.","contributorId":73817,"corporation":false,"usgs":true,"family":"Lippincott","given":"R.L.","email":"","affiliations":[],"preferred":false,"id":426130,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}} ,{"id":70030579,"text":"70030579 - 2007 - Simulation of submarine groundwater discharge salinity and temperature variations: Implications for remote detection","interactions":[],"lastModifiedDate":"2012-03-12T17:21:14","indexId":"70030579","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Simulation of submarine groundwater discharge salinity and temperature variations: Implications for remote detection","docAbstract":"A hydrological analysis using a numerical simulation was done to identify the transient response of the salinity and temperature of submarine groundwater discharge (SGD) and utilize the results to guide data collection. Results indicate that the amount of SGD fluctuates depending on the ocean stage and geology, with the greatest amount of SGD delivered at low tide when the aquifer is in direct hydraulic contact with the ocean. The salinity of SGD remains lower than the ocean throughout the year; however, the salinity difference between the aquifer and ocean is inversely proportional to the ocean stage. The temperature difference between the ocean and SGD fluctuates seasonally, with the greatest temperature differences occurring in summer and winter. The outcome of this research reveals that numerical modelling could potentially be used to guide data collection including aerial surveys using electromagnetic (EM) resistivity and thermal imagery.","largerWorkTitle":"IAHS-AISH Publication","conferenceTitle":"International Symposium: A New Focus on Groundwater - Seawater Interactions - 24th General Assembly of the In","conferenceDate":"2 July 2007 through 13 July 2007","conferenceLocation":"Perugia","language":"English","issn":"01447","isbn":"9781901502046","usgsCitation":"Dausman, A., Langevin, C., and Sukop, M., 2007, Simulation of submarine groundwater discharge salinity and temperature variations: Implications for remote detection, in IAHS-AISH Publication, no. 312, Perugia, 2 July 2007 through 13 July 2007, p. 272-280.","startPage":"272","endPage":"280","numberOfPages":"9","costCenters":[],"links":[{"id":239564,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"312","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9098e4b08c986b3195c4","contributors":{"authors":[{"text":"Dausman, A.M.","contributorId":99373,"corporation":false,"usgs":true,"family":"Dausman","given":"A.M.","affiliations":[],"preferred":false,"id":427729,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Langevin, C.D.","contributorId":25976,"corporation":false,"usgs":true,"family":"Langevin","given":"C.D.","email":"","affiliations":[],"preferred":false,"id":427727,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Sukop, M.C.","contributorId":88468,"corporation":false,"usgs":true,"family":"Sukop","given":"M.C.","affiliations":[],"preferred":false,"id":427728,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}} ,{"id":70030617,"text":"70030617 - 2007 - Numerical modelling to determine freshwater/saltwater interface configuration in a low-gradient coastal wetland aquifer","interactions":[],"lastModifiedDate":"2012-03-12T17:21:13","indexId":"70030617","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":24,"text":"Conference Paper"},"publicationSubtype":{"id":19,"text":"Conference Paper"},"title":"Numerical modelling to determine freshwater/saltwater interface configuration in a low-gradient coastal wetland aquifer","docAbstract":"A coupled hydrodynamic surface-water/groundwater model with salinity transport is used to examine the aquifer salinity interface in the coastal wetlands of Everglades National Park in Florida, USA. The hydrology differs from many other coastal areas in that inland water levels are often higher than land surface, the flow gradients are small, and, along parts of the coastline, the wetland is separated from the offshore waters by a natural embankment. Examining the model-simulated aquifer salinities along a transect that cuts the coastal embankment, a small zone of fresh groundwater is seen beneath the embankment, which varies seasonally in size and salinity. The simulated surface-water and groundwater levels suggest that this zone exists because of ponding of surface water at the coastal embankment, creating freshwater underflow to the offshore waters. The seasonal variability in the freshwater zone indicates that it is sensitive to the wetland flows and water levels. The small size of the zone in the simulation indicates that a model with a higher spatial resolution could probably depict the zone more accurately. The coastal ecology is strongly affected by the salinity of the shallow groundwater and the coastal freshwater zone is sensitive to wetland flows and levels. In this environment, predicting the aquifer salinity interface in coastal wetlands is important in examining the effects of changing water deliveries associated with ecosystem restoration efforts.","largerWorkTitle":"IAHS-AISH Publication","conferenceTitle":"International Symposium: A New Focus on Groundwater - Seawater Interactions - 24th General Assembly of the In","conferenceDate":"2 July 2007 through 13 July 2007","conferenceLocation":"Perugia","language":"English","issn":"01447","isbn":"9781901502046","usgsCitation":"Swain, E., and Wolfert, M., 2007, Numerical modelling to determine freshwater/saltwater interface configuration in a low-gradient coastal wetland aquifer, in IAHS-AISH Publication, no. 312, Perugia, 2 July 2007 through 13 July 2007, p. 264-271.","startPage":"264","endPage":"271","numberOfPages":"8","costCenters":[],"links":[{"id":239598,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"issue":"312","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a6901e4b0c8380cd73af7","contributors":{"authors":[{"text":"Swain, E. 0000-0001-7168-708X","orcid":"https://orcid.org/0000-0001-7168-708X","contributorId":82122,"corporation":false,"usgs":true,"family":"Swain","given":"E.","affiliations":[],"preferred":false,"id":427883,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wolfert, M.","contributorId":96474,"corporation":false,"usgs":true,"family":"Wolfert","given":"M.","email":"","affiliations":[],"preferred":false,"id":427884,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70030727,"text":"70030727 - 2007 - GIS methodology for quantifying channel change in Las Vegas, Nevada","interactions":[],"lastModifiedDate":"2012-03-12T17:21:01","indexId":"70030727","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2529,"text":"Journal of the American Water Resources Association","active":true,"publicationSubtype":{"id":10}},"title":"GIS methodology for quantifying channel change in Las Vegas, Nevada","docAbstract":"This study applies spatial analyses to examine the consequences of accelerated urban expansion on a hydrologic system over a period of 24 years. Three sets of historical aerial photos are used in a GIS analysis to document the geomorphic history of Las Vegas Wash, which drains the rapidly growing Las Vegas urban area in southern Nevada. New spatial techniques are introduced to make quantitative measurements of the erosion at three specific time intervals in the hydrologic evolution of the channel and floodplain. Unlike other erosion studies that use two different elevation surfaces to assess erosion, this study used a single elevation surface to remove systematic and nonsystemic elevation errors. The spatial analysis quantifies channel changes for discrete time periods, calculates erosion volumes, and provides a foundation to examine how the specific mechanisms related to urban expansion have affected Las Vegas Wash. The erosion calculated over 24 years is the largest documented sediment loss attributed to the effect of rapid urban growth. ?? 2007 American Water Resources Association.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of the American Water Resources Association","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1111/j.1752-1688.2007.00073.x","issn":"1093474X","usgsCitation":"Buckingham, S., and Whitney, J., 2007, GIS methodology for quantifying channel change in Las Vegas, Nevada: Journal of the American Water Resources Association, v. 43, no. 4, p. 888-898, https://doi.org/10.1111/j.1752-1688.2007.00073.x.","startPage":"888","endPage":"898","numberOfPages":"11","costCenters":[],"links":[{"id":211767,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1752-1688.2007.00073.x"},{"id":239119,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"43","issue":"4","noUsgsAuthors":false,"publicationDate":"2007-06-28","publicationStatus":"PW","scienceBaseUri":"505a146ae4b0c8380cd54a15","contributors":{"authors":[{"text":"Buckingham, S.E.","contributorId":9454,"corporation":false,"usgs":true,"family":"Buckingham","given":"S.E.","email":"","affiliations":[],"preferred":false,"id":428408,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Whitney, J.W.","contributorId":27437,"corporation":false,"usgs":true,"family":"Whitney","given":"J.W.","email":"","affiliations":[],"preferred":false,"id":428409,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}} ,{"id":70030742,"text":"70030742 - 2007 - Biological effects of anthropogenic contaminants in the San Francisco Estuary","interactions":[],"lastModifiedDate":"2023-07-26T12:16:24.529911","indexId":"70030742","displayToPublicDate":"2007-01-01T00:00:00","publicationYear":"2007","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1561,"text":"Environmental Research","active":true,"publicationSubtype":{"id":10}},"title":"Biological effects of anthropogenic contaminants in the San Francisco Estuary","docAbstract":"Concentrations of many anthropogenic contaminants in the San Francisco Estuary exist at levels that have been associated with biological effects elsewhere, so there is a potential for them to cause biological effects in the Estuary. The purpose of this paper is to summarize information about biological effects on the Estuary's plankton, benthos, fish, birds, and mammals, gathered since the early 1990s, focusing on key accomplishments. These studies have been conducted at all levels of biological organization (sub-cellular through communities), but have included only a small fraction of the organisms and contaminants of concern in the region. The studies summarized provide a body of evidence that some contaminants are causing biological impacts in some biological resources in the Estuary. However, no general patterns of effects were apparent in space and time, and no single contaminant was consistently related to effects among the biota considered. These conclusions reflect the difficulty in demonstrating biological effects due specifically to contamination because there is a wide range of sensitivity to contaminants among the Estuary's many organisms. Additionally, the spatial and temporal distribution of contamination in the Estuary is highly variable, and levels of contamination covary with other environmental factors, such as freshwater inflow or sediment-type. Federal and State regulatory agencies desire to develop biological criteria to protect the Estuary's biological resources. Future studies of biological effects in San Francisco Estuary should focus on the development of meaningful indicators of biological effects, and on key organism and contaminants of concern in long-term, multifaceted studies that include laboratory and field experiments to determine cause and effect to adequately inform management and regulatory decisions.
[1] Chemical conditions were perturbed in an aquifer with an ambient pH of 5.9 and wastewater-derived adsorbed zinc (Zn) and phosphate (P) contamination by injecting a pulse of amended groundwater. The injected groundwater had low concentrations of dissolved Zn and P, a pH value of 4.5 resulting from equilibration with carbon dioxide gas, and added potassium bromide (KBr). Downgradient of the injection, breakthrough of nonreactive Br and total dissolved carbonate concentrations in excess of ambient values (excess TCO2) were accompanied by a decrease in pH values and over twentyfold increases in dissolved Zn concentrations above preinjection values. Peak concentrations of Br and excess TCO2 were followed by slow increases in pH values accompanied by significant increases in dissolved P above preinjection concentrations. The injected tracers mobilized a significant mass of wastewater-derived Zn. Reactive transport simulations incorporating surface complexation models for adsorption of Zn, P, hydrogen ions, and major cations onto the aquifer sediments, calibrated using laboratory experimental data, captured most of the important trends observed during the experiment. These include increases in Zn concentrations in response to the pH perturbation, perturbations in major cation concentrations, attenuation of the pH perturbation with transport distance, and increases in alkalinity with transport distance. Observed desorption of P in response to chemical perturbations was not predicted, possibly because of a disparity between the range of chemical conditions in the calibration data set and those encountered during the field experiment. Zinc and P desorbed rapidly in response to changing chemical conditions despite decades of contact with the sediments. Surface complexation models with relatively few parameters in the form of logK values and site concentrations show considerable promise for describing the influence of variable chemistry on the transport of adsorbing contaminants.