{"pageNumber":"996","pageRowStart":"24875","pageSize":"25","recordCount":40818,"records":[{"id":70030650,"text":"70030650 - 2006 - Effects of land cover on water table, soil moisture, evapotranspiration, and groundwater recharge: A Field observation and analysis","interactions":[],"lastModifiedDate":"2012-03-12T17:21:14","indexId":"70030650","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","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":"Effects of land cover on water table, soil moisture, evapotranspiration, and groundwater recharge: A Field observation and analysis","docAbstract":"The effects of land cover on water table, soil moisture, evapotranspiration, and groundwater recharge were studied with water level measurements collected from two monitoring wells over a period of 122 days. The two wells were installed under similar conditions except that one was drilled on the east side of a creek which was covered with grass, and the other on the west side of the creek which was burned into a bare ground. Substantial differences in water level fluctuations were observed at these two wells. The water level in the east grass (EG) well was generally lower and had much less response to rainfall events than the west no-grass (WNG) well. Grass cover lowered the water table, reduced soil moisture through ET losses, and thus reduced groundwater recharge. The amount of ET by the grass estimated with a water table recession model decreased exponentially from 7.6 mm/day to zero as the water table declined from near the ground surface to 1.42 m below the ground surface in 33 days. More groundwater recharge was received on the WNG side than on the EG side following large rainfall events and by significant slow internal downward drainage which may last many days after rainfall. Because of the decreased ET and increased R, significantly more baseflow and chemical loads may be generated from a bare ground watershed compared to a vegetated watershed. ?? 2005 Elsevier Ltd All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Hydrology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jhydrol.2005.06.044","issn":"00221694","usgsCitation":"Zhang, Y., and Schilling, K.E., 2006, Effects of land cover on water table, soil moisture, evapotranspiration, and groundwater recharge: A Field observation and analysis: Journal of Hydrology, v. 319, no. 1-4, p. 328-338, https://doi.org/10.1016/j.jhydrol.2005.06.044.","startPage":"328","endPage":"338","numberOfPages":"11","costCenters":[],"links":[{"id":239600,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":212159,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jhydrol.2005.06.044"}],"volume":"319","issue":"1-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0733e4b0c8380cd515dc","contributors":{"authors":[{"text":"Zhang, Y.-K.","contributorId":44309,"corporation":false,"usgs":true,"family":"Zhang","given":"Y.-K.","email":"","affiliations":[],"preferred":false,"id":428037,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Schilling, K. E.","contributorId":61982,"corporation":false,"usgs":true,"family":"Schilling","given":"K.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":428038,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70028121,"text":"70028121 - 2006 - Time series and recurrence interval models to predict the vulnerability of streams to episodic acidification in Shenandoah National Park, Virginia","interactions":[],"lastModifiedDate":"2018-11-06T13:51:05","indexId":"70028121","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","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":"Time series and recurrence interval models to predict the vulnerability of streams to episodic acidification in Shenandoah National Park, Virginia","docAbstract":"<p><span>Acid rain affects headwater streams by temporarily reducing the acid‐neutralizing capacity (ANC) of the water, a process termed episodic acidification. The increase in acidic components in stream water can have deleterious effects on the aquatic biota. Although acidic deposition is uniform across Shenandoah National Park (SNP) in north central Virginia, the stream water quality response during rain events varies substantially. This response is a function of the catchment's underlying geology and topography. Geologic and topographic data for SNP's 231 catchments are readily available; however, long‐term measurements (tens of years) of ANC and accompanying discharge are not and would be prohibitively expensive to collect. Transfer function time series models were developed to predict hourly ANC from discharge for five SNP catchments with long‐term water‐quality and discharge records. Hourly ANC predictions over short time periods (≤1 week) were averaged, and distributions of the recurrence intervals of annual water‐year minimum ANC values were model‐simulated for periods of 6, 24, 72, and 168 hours. The distributions were extrapolated to the rest of the SNP catchments on the basis of catchment geology and topography. On the basis of the models, large numbers of SNP streams have 6‐ to 168‐hour periods of low‐ANC values, which may stress resident fish populations. Smaller catchments are more vulnerable to episodic acidification than larger catchments underlain by the same bedrock. Catchments with similar topography and size are more vulnerable if underlain by less basaltic/carbonate bedrock. Many catchments are predicted to have successive years of low‐ANC values potentially sufficient to extirpate some species.</span></p>","language":"English","publisher":"American Geophysical Union","doi":"10.1029/2005WR004740","usgsCitation":"Deviney, F.A., Rice, K.C., and Hornberger, G., 2006, Time series and recurrence interval models to predict the vulnerability of streams to episodic acidification in Shenandoah National Park, Virginia: Water Resources Research, v. 42, no. 9, Article W09405; 14 p., https://doi.org/10.1029/2005WR004740.","productDescription":"Article W09405; 14 p.","costCenters":[{"id":614,"text":"Virginia Water Science Center","active":true,"usgs":true},{"id":37280,"text":"Virginia and West Virginia Water Science Center ","active":true,"usgs":true}],"links":[{"id":477567,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1029/2005wr004740","text":"Publisher Index Page"},{"id":237016,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Virginia","otherGeospatial":"Shenandoah National Park","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -78.20068359374999,\n              38.6275996886131\n            ],\n            [\n              -78.1512451171875,\n              38.7283759182398\n            ],\n            [\n              -78.12103271484375,\n              38.76693348394693\n            ],\n            [\n              -78.1182861328125,\n              38.86109762182888\n            ],\n            [\n              -78.19244384765625,\n              38.92522904714054\n            ],\n            [\n              -78.25286865234375,\n              38.86965182408357\n            ],\n            [\n              -78.24188232421875,\n              38.83756825896614\n            ],\n            [\n              -78.30230712890624,\n              38.841846903808985\n            ],\n            [\n              -78.3929443359375,\n              38.77121637244273\n            ],\n            [\n              -78.4259033203125,\n              38.713375686254714\n            ],\n            [\n              -78.3984375,\n              38.638327308061875\n            ],\n            [\n              -78.4918212890625,\n              38.55031345037904\n            ],\n            [\n              -78.5577392578125,\n              38.567495358827344\n            ],\n            [\n              -78.59344482421875,\n              38.51378825951165\n            ],\n            [\n              -78.55224609374999,\n              38.436379603\n            ],\n            [\n              -78.607177734375,\n              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38.371808917147554\n            ],\n            [\n              -78.3544921875,\n              38.44498466889473\n            ],\n            [\n              -78.31054687499999,\n              38.50948995925553\n            ],\n            [\n              -78.23638916015625,\n              38.55031345037904\n            ],\n            [\n              -78.23638916015625,\n              38.59326051987162\n            ],\n            [\n              -78.20068359374999,\n              38.6275996886131\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}\n","volume":"42","issue":"9","noUsgsAuthors":false,"publicationDate":"2006-09-13","publicationStatus":"PW","scienceBaseUri":"505bb3b0e4b08c986b325f47","contributors":{"authors":[{"text":"Deviney, Frank A.","contributorId":22447,"corporation":false,"usgs":true,"family":"Deviney","given":"Frank","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":416640,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rice, Karen C. 0000-0002-9356-5443 kcrice@usgs.gov","orcid":"https://orcid.org/0000-0002-9356-5443","contributorId":1998,"corporation":false,"usgs":true,"family":"Rice","given":"Karen","email":"kcrice@usgs.gov","middleInitial":"C.","affiliations":[{"id":614,"text":"Virginia Water Science Center","active":true,"usgs":true}],"preferred":false,"id":416642,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Hornberger, George M.","contributorId":63894,"corporation":false,"usgs":true,"family":"Hornberger","given":"George M.","affiliations":[],"preferred":false,"id":416641,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":79589,"text":"ofr20061318 - 2006 - Deschutes Estuary feasibility study: Hydrodynamics and sediment transport modeling","interactions":[],"lastModifiedDate":"2023-09-01T21:35:25.751519","indexId":"ofr20061318","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":5,"text":"USGS Numbered Series"},"seriesTitle":{"id":330,"text":"Open-File Report","code":"OFR","onlineIssn":"2331-1258","printIssn":"0196-1497","active":true,"publicationSubtype":{"id":5}},"seriesNumber":"2006-1318","title":"Deschutes Estuary feasibility study: Hydrodynamics and sediment transport modeling","docAbstract":"<p>Continual sediment accumulation in Capitol Lake since the damming of the Deschutes River in 1951 has altered the initial morphology of the basin. As part of the Deschutes River Estuary Feasibility Study (DEFS), the United States Geological Survey (USGS) was tasked to model how tidal and storm processes will influence the river, lake and lower Budd Inlet should estuary restoration occur. Understanding these mechanisms will assist in developing a scientifically sound assessment on the feasibility of restoring the estuary.</p>\n<br>\n<p>The goals of the DEFS are as follows.</p>\n<br>\n<p>- Increase understanding of the estuary alternative to the same level as managing the lake environment.</p>\n<p>- Determine the potential to create a viable, self sustaining estuary at Capitol Lake, given all the existing physical constraints and the urban setting.</p>\n<p>- Create a net-benefit matrix which will allow a fair evaluation of overall benefits and costs of various alternative scenarios.</p>\n<p>- Provide the completed study to the CLAMP Steering Committee so that a recommendation about a long-term aquatic environment of the basin can be made.</p>\n<br>\n<p>The hydrodynamic and sediment transport modeling task developed a number of different model simulations using a process-based morphological model, Delft3D, to help address these goals. Modeling results provide a qualitative assessment of estuarine behavior both prior to dam construction and after various post-dam removal scenarios. Quantitative data from the model is used in the companion biological assessment and engineering design components of the overall study.</p>\n<br>\n<p>Overall, the modeling study found that after dam removal, tidal and estuarine processes are immediately restored, with marine water from Budd Inlet carried into North and Middle Basin on each rising tide and mud flats being exposed with each falling tide. Within the first year after dam removal, tidal processes, along with the occasional river floods, act to modify the estuary bed by redistributing sediment through erosion and deposition. The morphological response of the bed is rapid during the first couple of years, then slows as a dynamic equilibrium is reached within three to five years. By ten years after dam removal, the overall hydrodynamic and morphologic behavior of the estuary is similar to the pre-dam estuary, with the exception of South Basin, which has been permanently modified by human activities.</p>\n<br>\n<p>In addition to a qualitative assessment of estuarine behavior, process-based modeling provides the ability address specific questions to help to inform decision-making. Considering that predicting future conditions of a complex estuarine environment is wrought with uncertainties, quantitative results in this report are often expressed in terms of ranges of possible outcomes.</p>","language":"English","publisher":"U.S. Geological Survey","publisherLocation":"Reston, VA","doi":"10.3133/ofr20061318","usgsCitation":"George, D.A., Gelfenbaum, G., Lesser, G., and Stevens, A., 2006, Deschutes Estuary feasibility study: Hydrodynamics and sediment transport modeling (Version 1.0): U.S. Geological Survey Open-File Report 2006-1318, Report: 222 p.; 2 Appendixes: 177 p.; Metadata, https://doi.org/10.3133/ofr20061318.","productDescription":"Report: 222 p.; 2 Appendixes: 177 p.; Metadata","temporalStart":"2005-02-16","temporalEnd":"2005-02-17","costCenters":[{"id":645,"text":"Western Coastal and Marine Geology","active":false,"usgs":true}],"links":[{"id":420428,"rank":6,"type":{"id":36,"text":"NGMDB Index Page"},"url":"https://ngmdb.usgs.gov/Prodesc/proddesc_80585.htm","linkFileType":{"id":5,"text":"html"}},{"id":9208,"rank":5,"type":{"id":15,"text":"Index Page"},"url":"https://pubs.usgs.gov/of/2006/1318/","linkFileType":{"id":5,"text":"html"}},{"id":192369,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/usgs_thumb.jpg"},{"id":295746,"rank":4,"type":{"id":16,"text":"Metadata"},"url":"https://pubs.usgs.gov/of/2006/1318/CapitolLakeSeds.html","linkFileType":{"id":5,"text":"html"}},{"id":295744,"rank":3,"type":{"id":11,"text":"Document"},"url":"https://pubs.usgs.gov/of/2006/1318/of2006-1318.pdf","linkFileType":{"id":1,"text":"pdf"}},{"id":295745,"rank":2,"type":{"id":3,"text":"Appendix"},"url":"https://pubs.usgs.gov/of/2006/1318/of2006-1318_appendixes.pdf","linkFileType":{"id":1,"text":"pdf"}}],"country":"United States","state":"Washington","otherGeospatial":"Deschutes Estuary","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -122.9133,\n              47.0619\n            ],\n            [\n              -122.9133,\n              47.0183\n            ],\n            [\n              -122.8914,\n              47.0183\n            ],\n            [\n              -122.8914,\n              47.0619\n            ],\n            [\n              -122.9133,\n              47.0619\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","edition":"Version 1.0","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4ab0e4b07f02db66dd64","contributors":{"authors":[{"text":"George, Douglas A.","contributorId":60328,"corporation":false,"usgs":true,"family":"George","given":"Douglas","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":290306,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Gelfenbaum, Guy","contributorId":79844,"corporation":false,"usgs":true,"family":"Gelfenbaum","given":"Guy","affiliations":[],"preferred":false,"id":290307,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lesser, Giles","contributorId":88216,"corporation":false,"usgs":true,"family":"Lesser","given":"Giles","email":"","affiliations":[],"preferred":false,"id":290308,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Stevens, Andrew W.","contributorId":89093,"corporation":false,"usgs":true,"family":"Stevens","given":"Andrew W.","affiliations":[],"preferred":false,"id":290309,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70028049,"text":"70028049 - 2006 - Patterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline","interactions":[],"lastModifiedDate":"2017-06-28T15:03:08","indexId":"70028049","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2158,"text":"Journal of Animal Ecology","active":true,"publicationSubtype":{"id":10}},"title":"Patterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline","docAbstract":"<p>1. Growth models for body mass and length were fitted to data collected from 1842 sea otters&nbsp;<i>Enhydra lutris</i>&nbsp;shot or live-captured throughout south-west Alaska between 1967 and 2004. Growth curves were constructed for each of two main year groups: 1967–71 when the population was at or near carrying capacity and 1992–97 when the population was in steep decline. Analyses of data collected from animals caught during 2004, when the population density was very low, were precluded by a small sample size and consequently only examined incidentally to the main growth curves.</p><p><br><span class=\"bullet\">2.&nbsp;</span>Growth curves demonstrated a significant increase in body mass and body length at age in the 1990s. Asymptotic values of body mass were 12–18% higher in the 1990s than in the 1960s/70s, and asymptotic values for body length were 10–11% higher between the same periods. Data collected in 2004 suggest a continued increase in body size, with nearly all data points for mass and length falling significantly above the 1990s growth curves.</p><p><br><span class=\"bullet\">3.&nbsp;</span>In addition to larger asymptotic values for mass and length, the rate of growth towards asymptotic values was more rapid in the 1990s than in the 1960s/70s: sea otters reached 95% of asymptotic body mass and body length 1–2&nbsp;years earlier in the 1990s.</p><p><br><span class=\"bullet\">4.&nbsp;</span>Body condition (as measured by the log mass/log length ratio) was significantly greater in males than in females. There was also an increasing trend from the 1960s/70s through 2004 despite much year-to-year variation.</p><p><br><span class=\"bullet\">5.&nbsp;</span>Population age structures differed significantly between the 1960s/70s and the 1990s with the latter distribution skewed toward younger age classes (indicating an altered l<sub>x</sub>function) suggesting almost complete relaxation of age-dependent mortality patterns (i.e. those typical of food-limited populations).</p><p><br><span class=\"bullet\">6.&nbsp;</span>This study spanned a period of time over which the population status of sea otters in the Aleutian archipelago declined precipitously from levels at or near equilibrium densities at some islands in the 1960s/70s to &lt;&nbsp;5% of estimated carrying capacity by the late 1990s. The results of this study indicate an improved overall health of sea otters over the period of decline and suggest that limited nutritional resources were not the cause of the observed reduced population abundance. Our findings are consistent with the hypothesis that the decline was caused by increased killer whale predation.<br></p>","language":"English","publisher":"Wiley","doi":"10.1111/j.1365-2656.2006.01117.x","issn":"00218790","usgsCitation":"Laidre, K., Estes, J.A., Tinker, M.T., Bodkin, J.L., Monson, D., and Schneider, K., 2006, Patterns of growth and body condition in sea otters from the Aleutian archipelago before and after the recent population decline: Journal of Animal Ecology, v. 75, no. 4, p. 978-989, https://doi.org/10.1111/j.1365-2656.2006.01117.x.","productDescription":"12 p.","startPage":"978","endPage":"989","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":477487,"rank":1,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1111/j.1365-2656.2006.01117.x","text":"Publisher Index Page"},{"id":236941,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"75","issue":"4","noUsgsAuthors":false,"publicationDate":"2006-06-23","publicationStatus":"PW","scienceBaseUri":"505a75d4e4b0c8380cd77d7e","contributors":{"authors":[{"text":"Laidre, K.L.","contributorId":88319,"corporation":false,"usgs":true,"family":"Laidre","given":"K.L.","email":"","affiliations":[],"preferred":false,"id":416322,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Estes, J. A.","contributorId":53319,"corporation":false,"usgs":true,"family":"Estes","given":"J.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":416319,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Tinker, M. T. 0000-0002-3314-839X","orcid":"https://orcid.org/0000-0002-3314-839X","contributorId":54152,"corporation":false,"usgs":false,"family":"Tinker","given":"M.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":416320,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Bodkin, James L. 0000-0003-1641-4438 jbodkin@usgs.gov","orcid":"https://orcid.org/0000-0003-1641-4438","contributorId":748,"corporation":false,"usgs":true,"family":"Bodkin","given":"James","email":"jbodkin@usgs.gov","middleInitial":"L.","affiliations":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true}],"preferred":true,"id":416323,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Monson, Daniel H. 0000-0002-4593-5673 dmonson@usgs.gov","orcid":"https://orcid.org/0000-0002-4593-5673","contributorId":140480,"corporation":false,"usgs":true,"family":"Monson","given":"Daniel H.","email":"dmonson@usgs.gov","affiliations":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true}],"preferred":false,"id":416321,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Schneider, K.","contributorId":106302,"corporation":false,"usgs":true,"family":"Schneider","given":"K.","email":"","affiliations":[],"preferred":false,"id":416324,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70028157,"text":"70028157 - 2006 - An effective medium inversion algorithm for gas hydrate quantification and its application to laboratory and borehole measurements of gas hydrate-bearing sediments","interactions":[],"lastModifiedDate":"2017-08-16T09:13:03","indexId":"70028157","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1803,"text":"Geophysical Journal International","active":true,"publicationSubtype":{"id":10}},"title":"An effective medium inversion algorithm for gas hydrate quantification and its application to laboratory and borehole measurements of gas hydrate-bearing sediments","docAbstract":"The presence of gas hydrate in marine sediments alters their physical properties. In some circumstances, gas hydrate may cement sediment grains together and dramatically increase the seismic P- and S-wave velocities of the composite medium. Hydrate may also form a load-bearing structure within the sediment microstructure, but with different seismic wave attenuation characteristics, changing the attenuation behaviour of the composite. Here we introduce an inversion algorithm based on effective medium modelling to infer hydrate saturations from velocity and attenuation measurements on hydrate-bearing sediments. The velocity increase is modelled as extra binding developed by gas hydrate that strengthens the sediment microstructure. The attenuation increase is modelled through a difference in fluid flow properties caused by different permeabilities in the sediment and hydrate microstructures. We relate velocity and attenuation increases in hydrate-bearing sediments to their hydrate content, using an effective medium inversion algorithm based on the self-consistent approximation (SCA), differential effective medium (DEM) theory, and Biot and squirt flow mechanisms of fluid flow. The inversion algorithm is able to convert observations in compressional and shear wave velocities and attenuations to hydrate saturation in the sediment pore space. We applied our algorithm to a data set from the Mallik 2L–38 well, Mackenzie delta, Canada, and to data from laboratory measurements on gas-rich and water-saturated sand samples. Predictions using our algorithm match the borehole data and water-saturated laboratory data if the proportion of hydrate contributing to the load-bearing structure increases with hydrate saturation. The predictions match the gas-rich laboratory data if that proportion decreases with hydrate saturation. We attribute this difference to differences in hydrate formation mechanisms between the two environments.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Geophysical Journal International","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","publisher":"Oxford University Press","doi":"10.1111/j.1365-246X.2006.03038.x","issn":"0956540X","usgsCitation":"Chand, S., Minshull, T., Priest, J., Best, A., Clayton, C., and Waite, W., 2006, An effective medium inversion algorithm for gas hydrate quantification and its application to laboratory and borehole measurements of gas hydrate-bearing sediments: Geophysical Journal International, v. 166, no. 2, p. 543-552, https://doi.org/10.1111/j.1365-246X.2006.03038.x.","productDescription":"10 p.","startPage":"543","endPage":"552","numberOfPages":"10","costCenters":[{"id":186,"text":"Coastal and Marine Geology Program","active":true,"usgs":true},{"id":678,"text":"Woods Hole Coastal and Marine Science Center","active":true,"usgs":true}],"links":[{"id":488257,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://hdl.handle.net/1912/1771","text":"External Repository"},{"id":237091,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":210231,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1365-246X.2006.03038.x"}],"volume":"166","issue":"2","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ea2ee4b0c8380cd486ae","contributors":{"authors":[{"text":"Chand, S.","contributorId":27384,"corporation":false,"usgs":true,"family":"Chand","given":"S.","email":"","affiliations":[],"preferred":false,"id":416816,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Minshull, T.A.","contributorId":75815,"corporation":false,"usgs":true,"family":"Minshull","given":"T.A.","email":"","affiliations":[],"preferred":false,"id":416819,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Priest, J.A.","contributorId":75869,"corporation":false,"usgs":true,"family":"Priest","given":"J.A.","email":"","affiliations":[],"preferred":false,"id":416820,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Best, A.I.","contributorId":75082,"corporation":false,"usgs":true,"family":"Best","given":"A.I.","email":"","affiliations":[],"preferred":false,"id":416818,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Clayton, C.R.I.","contributorId":7213,"corporation":false,"usgs":true,"family":"Clayton","given":"C.R.I.","email":"","affiliations":[],"preferred":false,"id":416815,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Waite, W.F.","contributorId":40329,"corporation":false,"usgs":true,"family":"Waite","given":"W.F.","email":"","affiliations":[],"preferred":false,"id":416817,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70175729,"text":"70175729 - 2006 - A model for autumn pelagic distribution of adult female polar bears in the Chukchi Seas, 1987-1994","interactions":[],"lastModifiedDate":"2024-08-06T12:10:59.179393","indexId":"70175729","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":18,"text":"Report"},"publicationSubtype":{"id":9,"text":"Other Report"},"title":"A model for autumn pelagic distribution of adult female polar bears in the Chukchi Seas, 1987-1994","docAbstract":"<p>We made predictions of polar bear (Ursus maritimus) autumn distribution in the Chukchi Sea with a Resource Selection Function (RSF) developed from 1198 satellite radio-collar locations on 124 adult female polar bears, 1987 &ndash; 1994. The RSF was created to assist in an aerial survey design for polar bears proposed by the U.S. Fish and Wildlife Service. The RSF was based on bathymetry and daily sea ice covariates extracted from passive microwave satellite imagery within the pelagic region &gt; 25 km from shore. The RSF indicated that polar bears selected habitats with intermediate amounts (~50%) of ice cover in close proximity to higher ice concentrations, and over relatively shallow waters. The RSF showed good predictive abilities for the years of its construct, worked best in October, and was robust to inter-annual variability. When evaluated with recent (1997 &ndash; 2005) data, the RSF performed well for October and November but poorly in September. This loss of predictive abilities appeared to be related to recent changes in habitat due to longer melt seasons and younger sea ice, and testing the retrospective model with a small sample of recent polar bears locations from a limited region of the Chukchi Sea. Contemporary applications of this RSF must consider three factors that could limit its utility: 1) 2 different sea ice phenology; 2) distributions of males and sub-adults; and 3) occupancy in nearshore habitats.</p>","language":"English","publisher":"U.S. Geological Survey","usgsCitation":"Durner, G.M., Douglas, D., Nielson, R.M., and Amstrup, S.C., 2006, A model for autumn pelagic distribution of adult female polar bears in the Chukchi Seas, 1987-1994, v, 62 p.","productDescription":"v, 62 p.","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"links":[{"id":326844,"rank":1,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"57b6dc2ee4b03fd6b7d94bf9","contributors":{"authors":[{"text":"Durner, George M. 0000-0002-3370-1191 gdurner@usgs.gov","orcid":"https://orcid.org/0000-0002-3370-1191","contributorId":3576,"corporation":false,"usgs":true,"family":"Durner","given":"George","email":"gdurner@usgs.gov","middleInitial":"M.","affiliations":[{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true},{"id":114,"text":"Alaska Science Center","active":true,"usgs":true}],"preferred":true,"id":646211,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Douglas, David C. 0000-0003-0186-1104 ddouglas@usgs.gov","orcid":"https://orcid.org/0000-0003-0186-1104","contributorId":150115,"corporation":false,"usgs":true,"family":"Douglas","given":"David C.","email":"ddouglas@usgs.gov","affiliations":[{"id":117,"text":"Alaska Science Center Biology WTEB","active":true,"usgs":true},{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true}],"preferred":true,"id":646212,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Nielson, R. M.","contributorId":22967,"corporation":false,"usgs":false,"family":"Nielson","given":"R.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":646213,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Amstrup, Steven C.","contributorId":67034,"corporation":false,"usgs":false,"family":"Amstrup","given":"Steven","email":"","middleInitial":"C.","affiliations":[{"id":13182,"text":"Polar Bears International","active":true,"usgs":false}],"preferred":false,"id":646214,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70031192,"text":"70031192 - 2006 - Precipitation of lead-zinc ores in the Mississippi Valley-type deposit at Treves, Cevennes region of southern France","interactions":[],"lastModifiedDate":"2015-04-27T14:03:32","indexId":"70031192","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1765,"text":"Geofluids","active":true,"publicationSubtype":{"id":10}},"title":"Precipitation of lead-zinc ores in the Mississippi Valley-type deposit at Treves, Cevennes region of southern France","docAbstract":"<p><span>The Tr&egrave;ves zinc&ndash;lead deposit is one of several Mississippi Valley-type (MVT) deposits in the C&eacute;vennes region of southern France. Fluid inclusion studies show that the ore was deposited at temperatures between approximately 80 and 150&deg;C from a brine that derived its salinity mainly from the evaporation of seawater past halite saturation. Lead isotope studies suggest that the metals were extracted from local basement rocks. Sulfur isotope data and studies of organic matter indicate that the reduced sulfur in the ores was derived from the reduction of Mesozoic marine sulfate by thermochemical sulfate reduction or bacterially mediated processes at a different time or place from ore deposition. The large range of&nbsp;</span><i>&delta;</i><sup>34</sup><span>S values determined for the minerals in the deposit (12.2&ndash;19.2&permil; for barite, 3.8&ndash;13.8&permil; for sphalerite and galena, and 8.7 to &minus;21.2&permil; for pyrite), are best explained by the mixing of fluids containing different sources of sulfur. Geochemical reaction path calculations, based on quantitative fluid inclusion data and constrained by field observations, were used to evaluate possible precipitation mechanisms. The most important precipitation mechanism was probably the mixing of fluids containing different metal and reduced sulfur contents. Cooling, dilution, and changes in pH of the ore fluid probably played a minor role in the precipitation of ores. The optimum results that produced the most metal sulfide deposition with the least amount of fluid was the mixing of a fluid containing low amounts of reduced sulfur with a sulfur-rich, metal poor fluid. In this scenario, large amounts of sphalerite and galena are precipitated, together with smaller quantities of pyrite precipitated and dolomite dissolved. The relative amounts of metal precipitated and dolomite dissolved in this scenario agree with field observations that show only minor dolomite dissolution during ore deposition. The modeling results demonstrate the important control of the reduced sulfur concentration on the Zn and Pb transport capacity of the ore fluid and the volumes of fluid required to form the deposit. The studies of the Tr&egrave;ves ores provide insights into the ore-forming processes of a typical MVT deposit in the C&eacute;vennes region. However, the extent to which these processes can be extrapolated to other MVT deposits in the C&eacute;vennes region is problematic. Nevertheless, the evidence for the extensive migration of fluids in the basement and sedimentary cover rocks in the C&eacute;vennes region suggests that the ore forming processes for the Tr&egrave;ves deposit must be considered equally viable possibilities for the numerous fault-controlled and mineralogically similar MVT deposits in the C&eacute;vennes region.</span></p>","language":"English","publisher":"Wiley","doi":"10.1111/j.1468-8123.2006.00126.x","issn":"14688115","usgsCitation":"Leach, D., Macquar, J., Lagneau, V., Leventhal, J., Emsbo, P., and Premo, W., 2006, Precipitation of lead-zinc ores in the Mississippi Valley-type deposit at Treves, Cevennes region of southern France: Geofluids, v. 6, no. 1, p. 24-44, https://doi.org/10.1111/j.1468-8123.2006.00126.x.","productDescription":"21 p.","startPage":"24","endPage":"44","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":238881,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211574,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1111/j.1468-8123.2006.00126.x"}],"country":"France","otherGeospatial":"Cevennes","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              2.0654296875,\n              43.37311218382002\n            ],\n            [\n              2.0654296875,\n              44.87144275016589\n            ],\n            [\n              5.6689453125,\n              44.87144275016589\n            ],\n            [\n              5.6689453125,\n              43.37311218382002\n            ],\n            [\n              2.0654296875,\n              43.37311218382002\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"6","issue":"1","noUsgsAuthors":false,"publicationDate":"2006-01-23","publicationStatus":"PW","scienceBaseUri":"505a811ce4b0c8380cd7b396","contributors":{"authors":[{"text":"Leach, D.","contributorId":47548,"corporation":false,"usgs":true,"family":"Leach","given":"D.","affiliations":[],"preferred":false,"id":430449,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Macquar, J.-C.","contributorId":41623,"corporation":false,"usgs":true,"family":"Macquar","given":"J.-C.","email":"","affiliations":[],"preferred":false,"id":430448,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lagneau, V.","contributorId":6250,"corporation":false,"usgs":true,"family":"Lagneau","given":"V.","email":"","affiliations":[],"preferred":false,"id":430446,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Leventhal, J.","contributorId":16583,"corporation":false,"usgs":true,"family":"Leventhal","given":"J.","email":"","affiliations":[],"preferred":false,"id":430447,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Emsbo, P.","contributorId":59901,"corporation":false,"usgs":true,"family":"Emsbo","given":"P.","affiliations":[],"preferred":false,"id":430450,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Premo, W. 0000-0001-9904-4801","orcid":"https://orcid.org/0000-0001-9904-4801","contributorId":100191,"corporation":false,"usgs":true,"family":"Premo","given":"W.","affiliations":[],"preferred":false,"id":430451,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70175717,"text":"70175717 - 2006 - Nest survival in dusky Canada geese (<i>Branta canadensis occidentalis</i>): Use of discrete-time models","interactions":[],"lastModifiedDate":"2017-05-08T07:59:42","indexId":"70175717","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3544,"text":"The Auk","onlineIssn":"1938-4254","printIssn":"0004-8038","active":true,"publicationSubtype":{"id":10}},"title":"Nest survival in dusky Canada geese (<i>Branta canadensis occidentalis</i>): Use of discrete-time models","docAbstract":"<p><span>The Dusky Canada Goose (</span><i>Branta canadensis occidentalis</i><span>) population that breeds in the Copper River Delta, Alaska, has declined substantially since the late 1970s. Persistent low numbers have been attributed to low productivity in recent years. We examined patterns in survival rates of 1,852 nests to better understand ecological processes that influenced productivity during 1997-2000. We compared 10 nonparametric models of daily survival rate of nests (DSR) that included variation among years, calendar dates, nest initiation dates, and nest ages with equivalent models based on parametric functions. The unequivocal best model included patterns of DSR that varied among discrete periods of years, calendar dates, and nest ages. Generally, DSR was low early in the nesting season and higher midseason. Across years, patterns in DSR were most variable early and late in the nesting season. Daily survival rates of nests declined between the first and second week after initiation, increased until the fourth week, and then declined during the last week before hatch. Nest survival probability estimates ranged from 0.07 to 0.71 across years and nest initiation dates. Mean rates of nest survival ranged between 0.21 and 0.31 each year. We suggest (1) considering models that do not limit estimates of daily nest survival to parametric forms; (2) placing greater emphasis on sample size when nests are rare, to obtain accurate estimates of nest survival; and (3) developing new techniques to estimate the number of nests initiated.</span></p>","language":"English","publisher":"American Ornithological Society","doi":"10.1642/0004-8038(2006)123[0198:NSIDCG]2.0.CO;2","issn":"00048038","usgsCitation":"Grand, J., Fondell, T., Miller, D., and Anthony, R.M., 2006, Nest survival in dusky Canada geese (<i>Branta canadensis occidentalis</i>): Use of discrete-time models: The Auk, v. 123, no. 1, p. 198-210, https://doi.org/10.1642/0004-8038(2006)123[0198:NSIDCG]2.0.CO;2.","productDescription":"13 p.","startPage":"198","endPage":"210","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":477441,"rank":0,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1642/0004-8038(2006)123[0198:nsidcg]2.0.co;2","text":"Publisher Index Page"},{"id":326825,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"123","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"57b6dc69e4b03fd6b7d94c6d","contributors":{"authors":[{"text":"Grand, J.B.","contributorId":11150,"corporation":false,"usgs":true,"family":"Grand","given":"J.B.","email":"","affiliations":[],"preferred":false,"id":646170,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Fondell, T.F.","contributorId":11154,"corporation":false,"usgs":true,"family":"Fondell","given":"T.F.","email":"","affiliations":[],"preferred":false,"id":646171,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Miller, Dick","contributorId":46054,"corporation":false,"usgs":true,"family":"Miller","given":"Dick","affiliations":[],"preferred":false,"id":646172,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Anthony, R. Michael","contributorId":54535,"corporation":false,"usgs":false,"family":"Anthony","given":"R.","email":"","middleInitial":"Michael","affiliations":[],"preferred":false,"id":646173,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":1015122,"text":"1015122 - 2006 - A permutation test for quantile regression","interactions":[],"lastModifiedDate":"2017-12-30T10:33:35","indexId":"1015122","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2151,"text":"Journal of Agricultural, Biological, and Environmental Statistics","active":true,"publicationSubtype":{"id":10}},"title":"A permutation test for quantile regression","docAbstract":"<p>A drop in dispersion, <i class=\"EmphasisTypeItalic \">F</i>-ratio like, permutation test (<i class=\"EmphasisTypeItalic \">D</i>) for linear quantile regression estimates (0≤τ≤1) had relative power ≥1 compared to quantile rank score tests (<i class=\"EmphasisTypeItalic \">T</i>) for hypotheses on parameters other than the intercept. Power was compared for combinations of sample sizes (<i class=\"EmphasisTypeItalic \">n</i>=20−300) and quantiles (τ=0.50−0.99) where both tests maintained valid Type I error rates in simulations with <i class=\"EmphasisTypeItalic \">p</i>=2 and 6 parameters in homogeneous and heterogeneous error models. The <i class=\"EmphasisTypeItalic \">D</i> test required two modifications of permuting residuals from null, reduced parameter models to maintain correct Type I error rates when null models were constrained through the origin or included multiple parameters. A double permutation scheme was used when null models were constrained through the origin and all but 1 of the zero residuals were deleted for null models with multiple parameters. Although there was considerable overlap in sample size, quantiles, and hypotheses where both the <i class=\"EmphasisTypeItalic \">D</i> and rank score tests maintained correct Type I error rates, we identified regions at smaller <i class=\"EmphasisTypeItalic \">n</i> and more extreme quantiles where one or the other maintained better error rates. Confidence intervals on parameters for an ecological application relating Lahontan cutthroat trout densities to stream channel width:depth were estimated by test inversion, demonstrating a smoother pattern of slightly narrower intervals across quantiles than those provided by the rank score test.</p>","language":"English","publisher":"Springer","doi":"10.1198/108571106X96835","usgsCitation":"Cade, B.S., and Richards, J.D., 2006, A permutation test for quantile regression: Journal of Agricultural, Biological, and Environmental Statistics, v. 11, no. 1, p. 106-126, https://doi.org/10.1198/108571106X96835.","productDescription":"21 p.","startPage":"106","endPage":"126","costCenters":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"links":[{"id":131759,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"11","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4b1fe4b07f02db6ab830","contributors":{"authors":[{"text":"Cade, Brian S. 0000-0001-9623-9849 cadeb@usgs.gov","orcid":"https://orcid.org/0000-0001-9623-9849","contributorId":1278,"corporation":false,"usgs":true,"family":"Cade","given":"Brian","email":"cadeb@usgs.gov","middleInitial":"S.","affiliations":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"preferred":true,"id":322233,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Richards, Jon D.","contributorId":181580,"corporation":false,"usgs":false,"family":"Richards","given":"Jon","email":"","middleInitial":"D.","affiliations":[],"preferred":false,"id":322232,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70028043,"text":"70028043 - 2006 - Flow and form in rehabilitation of large-river ecosystems: an example from the Lower Missouri River","interactions":[],"lastModifiedDate":"2016-08-18T15:30:54","indexId":"70028043","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1801,"text":"Geomorphology","active":true,"publicationSubtype":{"id":10}},"title":"Flow and form in rehabilitation of large-river ecosystems: an example from the Lower Missouri River","docAbstract":"<p>On large, intensively engineered rivers like the Lower Missouri, the template of the physical habitat is determined by the nearly independent interaction of channel form and flow regime. We evaluated the interaction between flow and form by modeling four combinations of modern and historical channel form and modern and historical flow regimes. The analysis used shallow, slow water (shallow-water habitat, SWH, defined as depths between 0 and 1.5 m, and current velocities between 0 and 0.75 m/s) as an indicator of habitat that has been lost on many intensively engineered rivers and one that is thought to be especially important in rearing of young fishes. Two-dimensional hydrodynamic models for modern and historical channels of the Lower Missouri River at Hermann, Missouri, indicate substantial differences between the two channels in total availability and spatial characteristics of SWH. In the modern channel, SWH is maximized at extremely low flows and in overbank flows, whereas the historical channel had substantially more SWH at all discharges and SWH increased with increasing discharge. The historical channel form produced 3-7 times the SWH area of the modern channel regardless of flow regime. The effect of flow regime is evident in increased within-year SWH variability with the natural flow regime, including significant seasonal peaks of SWH associated with spring flooding. Comparison with other reaches along the Lower Missouri River indicates that a) channel form is the dominant control of the availability of habitat even in reaches where the hydrograph is more intensively altered, and b) rehabilitation projects that move toward the historical condition can be successful in increasing topographic diversity and thereby decreasing sensitivity of the availability of habitat to flow regime. The relative efficacy of managing flow and form in creating SWH is useful information toward achieving socially acceptable rehabilitation of the ecosystem in large river systems.</p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.geomorph.2006.01.014","issn":"0169555X","usgsCitation":"Jacobson, R., and Galat, D., 2006, Flow and form in rehabilitation of large-river ecosystems: an example from the Lower Missouri River: Geomorphology, v. 77, no. 3-4, p. 249-269, https://doi.org/10.1016/j.geomorph.2006.01.014.","productDescription":"21 p.","startPage":"249","endPage":"269","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"links":[{"id":236834,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":210036,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.geomorph.2006.01.014"}],"volume":"77","issue":"3-4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a1237e4b0c8380cd5420c","contributors":{"authors":[{"text":"Jacobson, R. B. 0000-0002-8368-2064","orcid":"https://orcid.org/0000-0002-8368-2064","contributorId":92614,"corporation":false,"usgs":true,"family":"Jacobson","given":"R. B.","affiliations":[{"id":192,"text":"Columbia Environmental Research Center","active":true,"usgs":true}],"preferred":true,"id":416275,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Galat, D.L.","contributorId":54546,"corporation":false,"usgs":true,"family":"Galat","given":"D.L.","email":"","affiliations":[],"preferred":false,"id":416274,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":1015119,"text":"1015119 - 2006 - Flood pattern and weather determine Populus leaf litter breakdown and nitrogen dynamics on a cold desert floodplain","interactions":[],"lastModifiedDate":"2017-12-28T09:49:45","indexId":"1015119","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","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}},"displayTitle":"Flood pattern and weather determine <i>Populus</i> leaf litter breakdown and nitrogen dynamics on a cold desert floodplain","title":"Flood pattern and weather determine Populus leaf litter breakdown and nitrogen dynamics on a cold desert floodplain","docAbstract":"<p>Patterns and processes involved in litter breakdown on desert river floodplains are not well understood. We used leafpacks containing Fremont cottonwood (<i>Populus deltoides</i> subsp. <i>wislizenii</i>) leaf litter to investigate the roles of weather and microclimate, flooding (immersion), and macroinvertebrates on litter organic matter (OM) and nitrogen (N) loss on a floodplain in a cool-temperate semi-arid environment (Yampa River, northwestern Colorado, USA). Total mass of N in fresh autumn litter fell by ∼20% over winter and spring, but in most cases there was no further N loss prior to termination of the study after 653 days exposure, including up to 20 days immersion during the spring flood pulse. Final OM mass was 10–40% of initial values. The pattern of OM and N losses suggested most N would be released outside the flood season, when retention within the floodplain would be likely. The exclusion of macroinvertebrates modestly reduced the rate of OM loss (by about 10%) but had no effect on N dynamics over nine months. Immersion in floodwater accelerated OM loss, but modest variation in litter quality did not affect the breakdown rate. These results are consistent with the concept that decomposition on desert floodplains progresses much as does litter processing in desert uplands, but with periodic bouts of processing typical of aquatic environments when litter is inundated by floodwaters. The strong dependence of litter breakdown rate on weather and floods means that climate change or river flow management can easily disrupt floodplain nutrient dynamics.</p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.jaridenv.2005.06.022","usgsCitation":"Andersen, D., and Nelson, S.M., 2006, Flood pattern and weather determine Populus leaf litter breakdown and nitrogen dynamics on a cold desert floodplain: Journal of Arid Environments, v. 64, no. 4, p. 626-650, https://doi.org/10.1016/j.jaridenv.2005.06.022.","productDescription":"25 p.","startPage":"626","endPage":"650","costCenters":[{"id":291,"text":"Fort Collins Science Center","active":true,"usgs":true}],"links":[{"id":131756,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"64","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e49f2e4b07f02db5eec31","contributors":{"authors":[{"text":"Andersen, D.C.","contributorId":19119,"corporation":false,"usgs":true,"family":"Andersen","given":"D.C.","email":"","affiliations":[],"preferred":false,"id":322228,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Nelson, S. M.","contributorId":81853,"corporation":false,"usgs":false,"family":"Nelson","given":"S.","email":"","middleInitial":"M.","affiliations":[],"preferred":false,"id":322229,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70028116,"text":"70028116 - 2006 - Diurnal time-activity budgets of redheads (Aythya americana) wintering in seagrass beds and coastal ponds in Louisiana and Texas","interactions":[],"lastModifiedDate":"2019-06-17T15:13:31","indexId":"70028116","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","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}},"displayTitle":"Diurnal time-activity budgets of redheads (<i>Aythya americana</i>) wintering in seagrass beds and coastal ponds in Louisiana and Texas","title":"Diurnal time-activity budgets of redheads (Aythya americana) wintering in seagrass beds and coastal ponds in Louisiana and Texas","docAbstract":"<p><span>Diurnal time-activity budgets were determined for wintering redheads (</span><i class=\"EmphasisTypeItalic \">Aythya americana</i><span>) from estuarine seagrass beds in Louisiana (Chandeleur Sound) and Texas (Laguna Madre) and from ponds adjacent to the Laguna Madre. Activities differed (</span><i class=\"EmphasisTypeItalic \">p</i><span>&lt;0.0001) by location, month, and diurnal time period. Resting and feeding were the most frequent activities of redheads at the two estuarine sites, whereas drinking was almost nonexistent. Birds on ponds in Texas engaged most frequently in resting and drinking, but feeding was very infrequent. Redheads from the Louisiana estuarine site rested less than birds in Texas at either the Laguna Madre or freshwater ponds. Redheads in Louisiana fed more than birds in Texas; this was partially because of weather differences (colder temperatures in Louisiana), but the location effect was still significant even when we adjusted the model for weather effects. Redheads in Louisiana showed increased resting and decreased feeding as winter progressed, but redheads in Texas did not exhibit a seasonal pattern in either resting or feeding. In Louisiana, birds maintained a high level of feeding activity during the early morning throughout the winter, whereas afternoon feeding tapered off in mid- to late-winter. Texas birds showed a shift from morning feeding in early winter to afternoon feeding in late winter. Males and females at both Chandeleur Sound and Laguna Madre showed differences in their activities, but because the absolute difference seldom exceeded 2%, biological significance is questionable. Diurnal time-activity budgets of redheads on the wintering grounds are influenced by water salinities and the use of dietary fresh water, as well as by weather conditions, tides, and perhaps vegetation differences between sites. The opportunity to osmoregulate via dietary freshwater, vs. via nasal salt glands, may have a significant effect on behavioral allocations.</span></p>","language":"English","publisher":"Springer Nature","doi":"10.1007/s10750-006-0058-7","issn":"00188158","usgsCitation":"Michot, T., Woodin, M., Adair, S., and Moser, E., 2006, Diurnal time-activity budgets of redheads (Aythya americana) wintering in seagrass beds and coastal ponds in Louisiana and Texas: Hydrobiologia, v. 567, no. 1, p. 113-128, https://doi.org/10.1007/s10750-006-0058-7.","productDescription":"16 p.","startPage":"113","endPage":"128","costCenters":[],"links":[{"id":236911,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Louisiana, Texas","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -97.7178955078125,\n              25.83697740052369\n            ],\n            [\n              -96.98181152343749,\n              25.83697740052369\n            ],\n            [\n              -96.98181152343749,\n              27.868216579514076\n            ],\n            [\n              -97.7178955078125,\n              27.868216579514076\n            ],\n            [\n              -97.7178955078125,\n              25.83697740052369\n            ]\n          ]\n        ]\n      }\n    },\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -90.29388427734375,\n              29.191731712018708\n            ],\n            [\n              -89.17739868164062,\n              29.191731712018708\n            ],\n            [\n              -89.17739868164062,\n              30.27211440480969\n            ],\n            [\n              -90.29388427734375,\n              30.27211440480969\n            ],\n            [\n              -90.29388427734375,\n              29.191731712018708\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"567","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0341e4b0c8380cd503b8","contributors":{"authors":[{"text":"Michot, T.C. 0000-0002-7044-987X","orcid":"https://orcid.org/0000-0002-7044-987X","contributorId":43426,"corporation":false,"usgs":true,"family":"Michot","given":"T.C.","affiliations":[],"preferred":false,"id":416627,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Woodin, M.C.","contributorId":97307,"corporation":false,"usgs":true,"family":"Woodin","given":"M.C.","email":"","affiliations":[],"preferred":false,"id":416628,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Adair, S.E.","contributorId":8276,"corporation":false,"usgs":true,"family":"Adair","given":"S.E.","email":"","affiliations":[],"preferred":false,"id":416626,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Moser, E.B.","contributorId":6243,"corporation":false,"usgs":true,"family":"Moser","given":"E.B.","email":"","affiliations":[],"preferred":false,"id":416625,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70028120,"text":"70028120 - 2006 - Persistence of 10-year old Exxon Valdez oil on Gulf of Alaska beaches: The importance of boulder-armoring","interactions":[],"lastModifiedDate":"2017-03-08T12:21:51","indexId":"70028120","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2676,"text":"Marine Pollution Bulletin","active":true,"publicationSubtype":{"id":10}},"title":"Persistence of 10-year old Exxon Valdez oil on Gulf of Alaska beaches: The importance of boulder-armoring","docAbstract":"<p>Oil stranded as a result of the 1989 Exxon Valdez spill has persisted for &gt;10 years at study sites on Gulf of Alaska shores distant from the spill's origin. These sites were contaminated by \"oil mousse\", which persists in these settings due to armoring of underlying sediments and their included oil beneath boulders. The boulder-armored beaches that we resampled in 1999 showed continued contamination by subsurface oil, despite their exposure to moderate to high wave energies. Significant declines in surface oil cover occurred at all study sites. In contrast, mousse has persisted under boulders in amounts similar to what was present in 1994 and probably in 1989. Especially striking is the general lack of weathering of this subsurface oil over the last decade. Oil at five of the six armored-beach sites 10 years after the spill is compositionally similar to 11-day old Exxon Valdez oil. Analysis of movements in the boulder-armor that covers the study beaches reveals that only minor shifts have occurred since 1994, suggesting that over the last five, and probably over the last 10 years, boulder-armors have remained largely unmoved at the study sites. These findings emphasize the importance of particular geomorphic parameters in determining stranded oil persistence. Surface armoring, combined with stranding of oil mousse, results in the unexpectedly lengthy persistence of only lightly to moderately weathered oil within otherwise high-energy wave environments.</p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.marpolbul.2006.01.005","issn":"0025326X","usgsCitation":"Irvine, G.V., Mann, D.H., and Short, J.W., 2006, Persistence of 10-year old Exxon Valdez oil on Gulf of Alaska beaches: The importance of boulder-armoring: Marine Pollution Bulletin, v. 52, no. 9, p. 1011-1022, https://doi.org/10.1016/j.marpolbul.2006.01.005.","productDescription":"12 p.","startPage":"1011","endPage":"1022","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[{"id":114,"text":"Alaska Science Center","active":true,"usgs":true},{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true}],"links":[{"id":236982,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"country":"United States","state":"Alaska","otherGeospatial":"Cook Inlet, Gulf of Alaska, Prince William Sound","geographicExtents":"{\n  \"type\": \"FeatureCollection\",\n  \"features\": [\n    {\n      \"type\": \"Feature\",\n      \"properties\": {},\n      \"geometry\": {\n        \"type\": \"Polygon\",\n        \"coordinates\": [\n          [\n            [\n              -157.91748046875,\n              56.18225387824831\n            ],\n            [\n              -145.5908203125,\n              56.18225387824831\n            ],\n            [\n              -145.5908203125,\n              61.7419302246182\n            ],\n            [\n              -157.91748046875,\n              61.7419302246182\n            ],\n            [\n              -157.91748046875,\n              56.18225387824831\n            ]\n          ]\n        ]\n      }\n    }\n  ]\n}","volume":"52","issue":"9","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a76e0e4b0c8380cd7836a","contributors":{"authors":[{"text":"Irvine, Gail V. girvine@usgs.gov","contributorId":2368,"corporation":false,"usgs":true,"family":"Irvine","given":"Gail","email":"girvine@usgs.gov","middleInitial":"V.","affiliations":[{"id":116,"text":"Alaska Science Center Biology MFEB","active":true,"usgs":true}],"preferred":true,"id":416639,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Mann, Daniel H.","contributorId":67010,"corporation":false,"usgs":true,"family":"Mann","given":"Daniel","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":416637,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Short, Jeffrey W.","contributorId":26602,"corporation":false,"usgs":true,"family":"Short","given":"Jeffrey","email":"","middleInitial":"W.","affiliations":[],"preferred":false,"id":416638,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70028131,"text":"70028131 - 2006 - Spatial modeling of biological soil crusts to support rangeland assessment and monitoring","interactions":[],"lastModifiedDate":"2012-03-12T17:20:51","indexId":"70028131","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3228,"text":"Rangeland Ecology and Management","onlineIssn":"1551-5028","printIssn":"1550-7424","active":true,"publicationSubtype":{"id":10}},"title":"Spatial modeling of biological soil crusts to support rangeland assessment and monitoring","docAbstract":"Biological soil crusts are a diverse soil surface community, prevalent in semiarid regions, which function as ecosystem engineers and perform numerous important ecosystem services. Loss of crusts has been implicated as a factor leading to accelerated soil erosion and other forms of land degradation. To support assessment and monitoring efforts aimed at ensuring the sustainability of rangeland ecosystems, managers require spatially explicit information concerning potential cover and composition of biological soil crusts. We sampled low disturbance sites in Grand Staircase-Escalante National Monument (Utah, USA) to determine the feasibility of modeling the potential cover and composition of biological soil crusts in a large area. We used classification and regression trees to model cover of four crust types (light cyanobacterial, dark cyanobacterial, moss, lichen) and 1 cyanobacterial biomass proxy (chlorophyll a), based upon a parsimonious set of GIS (Geographic Information Systems) data layers (soil types, precipitation, and elevation). Soil type was consistently the best predictor, although elevation and precipitation were both invoked in the various models. Predicted and observed values for the dark cyanobacterial, moss, and lichen models corresponded moderately well (R 2 = 0.49, 0.64, 0.55, respectively). Cover of late successional crust elements (moss + lichen + dark cyanobacterial) was also successfully modeled (R2 = 0.64). We were less successful with models of light cyanobacterial cover (R2 = 0.22) and chlorophyll a (R2 = 0.09). We believe that our difficulty modeling chlorophyll a concentration is related to a severe drought and subsequent cyanobacterial mortality during the course of the study. These models provide the necessary reference conditions to facilitate the comparison between the actual cover and composition of biological soil crusts at a given site and their potential cover and composition condition so that sites in poor condition can be identified and management actions can be taken.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Rangeland Ecology and Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2111/05-179R1.1","issn":"15507424","usgsCitation":"Bowker, M.A., Belnap, J., and Miller, M.E., 2006, Spatial modeling of biological soil crusts to support rangeland assessment and monitoring: Rangeland Ecology and Management, v. 59, no. 5, p. 519-529, https://doi.org/10.2111/05-179R1.1.","startPage":"519","endPage":"529","numberOfPages":"11","costCenters":[],"links":[{"id":210308,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2111/05-179R1.1"},{"id":237192,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"59","issue":"5","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505b9487e4b08c986b31ab4b","contributors":{"authors":[{"text":"Bowker, M. A.","contributorId":18901,"corporation":false,"usgs":true,"family":"Bowker","given":"M.","email":"","middleInitial":"A.","affiliations":[],"preferred":false,"id":416683,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"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":416684,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Miller, M. E.","contributorId":104003,"corporation":false,"usgs":false,"family":"Miller","given":"M.","email":"","middleInitial":"E.","affiliations":[],"preferred":false,"id":416685,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70028092,"text":"70028092 - 2006 - Remote monitoring of fish in small streams: A unified approach using PIT tags","interactions":[],"lastModifiedDate":"2017-11-06T09:46:27","indexId":"70028092","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","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":"Remote monitoring of fish in small streams: A unified approach using PIT tags","docAbstract":"Accurate assessments of fish populations are often limited by re-observation or recapture events. Since the early 1990s, passive integrated transponders (PIT tags) have been used to understand the biology of many fish species. Until recently, PIT applications in small streams have been limited to physical recapture events. To maximize recapture probability, we constructed PIT antenna arrays in small streams to remotely detect individual fish. Experiences from two different laboratories (three case studies) allowed us to develop a unified approach to applying PIT technology for enhancing data assessments. Information on equipment, its installation, tag considerations, and array construction is provided. Theoretical and practical definitions are introduced to standardize metrics for assessing detection efficiency. We demonstrate how certain conditions (stream discharge, vibration, and ambient radio frequency noise) affect the detection efficiency and suggest that by monitoring these conditions, expectations of efficiency can be modified. We emphasize the importance of consistently estimating detection efficiency for fisheries applications.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Fisheries","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1577/1548-8446(2006)31[492:RMOFIS]2.0.CO;2","issn":"03632415","usgsCitation":"Zydlewski, G., Horton, G., Dubreuil, T., Letcher, B., Casey, S., and Zydlewski, J.D., 2006, Remote monitoring of fish in small streams: A unified approach using PIT tags: Fisheries, v. 31, no. 10, p. 492-502, https://doi.org/10.1577/1548-8446(2006)31[492:RMOFIS]2.0.CO;2.","startPage":"492","endPage":"502","numberOfPages":"11","costCenters":[],"links":[{"id":487558,"rank":10000,"type":{"id":41,"text":"Open Access External Repository Page"},"url":"https://digitalcommons.library.umaine.edu/sms_facpub/104","text":"External Repository"},{"id":237050,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":210201,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1577/1548-8446(2006)31[492:RMOFIS]2.0.CO;2"}],"volume":"31","issue":"10","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505aa6ede4b0c8380cd8510e","contributors":{"authors":[{"text":"Zydlewski, G.B.","contributorId":78119,"corporation":false,"usgs":true,"family":"Zydlewski","given":"G.B.","email":"","affiliations":[],"preferred":false,"id":416503,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Horton, G.","contributorId":53586,"corporation":false,"usgs":true,"family":"Horton","given":"G.","email":"","affiliations":[],"preferred":false,"id":416502,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Dubreuil, T.","contributorId":8664,"corporation":false,"usgs":true,"family":"Dubreuil","given":"T.","email":"","affiliations":[],"preferred":false,"id":416500,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Letcher, B. 0000-0003-0191-5678","orcid":"https://orcid.org/0000-0003-0191-5678","contributorId":14625,"corporation":false,"usgs":true,"family":"Letcher","given":"B.","affiliations":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"preferred":false,"id":416501,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Casey, S.","contributorId":80480,"corporation":false,"usgs":true,"family":"Casey","given":"S.","email":"","affiliations":[],"preferred":false,"id":416504,"contributorType":{"id":1,"text":"Authors"},"rank":5},{"text":"Zydlewski, Joseph D. 0000-0002-2255-2303 jzydlewski@usgs.gov","orcid":"https://orcid.org/0000-0002-2255-2303","contributorId":2004,"corporation":false,"usgs":true,"family":"Zydlewski","given":"Joseph","email":"jzydlewski@usgs.gov","middleInitial":"D.","affiliations":[{"id":199,"text":"Coop Res Unit Leetown","active":true,"usgs":true},{"id":365,"text":"Leetown Science Center","active":true,"usgs":true},{"id":198,"text":"Coop Res Unit Atlanta","active":true,"usgs":true}],"preferred":false,"id":416499,"contributorType":{"id":1,"text":"Authors"},"rank":6}]}}
,{"id":70028087,"text":"70028087 - 2006 - Landscape conditions predisposing grizzly bears to conflicts on private agricultural lands in the western USA","interactions":[],"lastModifiedDate":"2012-03-12T17:20:42","indexId":"70028087","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","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":"Landscape conditions predisposing grizzly bears to conflicts on private agricultural lands in the western USA","docAbstract":"We used multiple logistic regression to model how different landscape conditions contributed to the probability of human-grizzly bear conflicts on private agricultural ranch lands. We used locations of livestock pastures, traditional livestock carcass disposal areas (boneyards), beehives, and wetland-riparian associated vegetation to model the locations of 178 reported human-grizzly bear conflicts along the Rocky Mountain East Front, Montana, USA during 1986-2001. We surveyed 61 livestock producers in the upper Teton watershed of north-central Montana, to collect spatial and temporal data on livestock pastures, boneyards, and beehives for the same period, accounting for changes in livestock and boneyard management and beehive location and protection, for each season. We used 2032 random points to represent the null hypothesis of random location relative to potential explanatory landscape features, and used Akaike's Information Criteria (AIC/AICC) and Hosmer-Lemeshow goodness-of-fit statistics for model selection. We used a resulting \"best\" model to map contours of predicted probabilities of conflict, and used this map for verification with an independent dataset of conflicts to provide additional insights regarding the nature of conflicts. The presence of riparian vegetation and distances to spring, summer, and fall sheep or cattle pastures, calving and sheep lambing areas, unmanaged boneyards, and fenced and unfenced beehives were all associated with the likelihood of human-grizzly bear conflicts. Our model suggests that collections of attractants concentrated in high quality bear habitat largely explain broad patterns of human-grizzly bear conflicts on private agricultural land in our study area. ?? 2005 Elsevier Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Biological Conservation","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.biocon.2005.12.001","issn":"00063207","usgsCitation":"Wilson, S., Madel, M., Mattson, D., Graham, J., and Merrill, T., 2006, Landscape conditions predisposing grizzly bears to conflicts on private agricultural lands in the western USA: Biological Conservation, v. 130, no. 1, p. 47-59, https://doi.org/10.1016/j.biocon.2005.12.001.","startPage":"47","endPage":"59","numberOfPages":"13","costCenters":[],"links":[{"id":210147,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.biocon.2005.12.001"},{"id":236979,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"130","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a4404e4b0c8380cd667a3","contributors":{"authors":[{"text":"Wilson, S.M.","contributorId":52731,"corporation":false,"usgs":true,"family":"Wilson","given":"S.M.","email":"","affiliations":[],"preferred":false,"id":416484,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Madel, M.J.","contributorId":33111,"corporation":false,"usgs":true,"family":"Madel","given":"M.J.","email":"","affiliations":[],"preferred":false,"id":416483,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mattson, D.J.","contributorId":57022,"corporation":false,"usgs":true,"family":"Mattson","given":"D.J.","email":"","affiliations":[],"preferred":false,"id":416485,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Graham, J.M.","contributorId":57651,"corporation":false,"usgs":true,"family":"Graham","given":"J.M.","email":"","affiliations":[],"preferred":false,"id":416486,"contributorType":{"id":1,"text":"Authors"},"rank":4},{"text":"Merrill, T.","contributorId":89301,"corporation":false,"usgs":true,"family":"Merrill","given":"T.","email":"","affiliations":[],"preferred":false,"id":416487,"contributorType":{"id":1,"text":"Authors"},"rank":5}]}}
,{"id":70028077,"text":"70028077 - 2006 - The influence of hazard models on GIS-based regional risk assessments and mitigation policies","interactions":[],"lastModifiedDate":"2012-03-12T17:20:42","indexId":"70028077","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2069,"text":"International Journal of Risk Assessment and Management","active":true,"publicationSubtype":{"id":10}},"title":"The influence of hazard models on GIS-based regional risk assessments and mitigation policies","docAbstract":"Geographic information systems (GIS) are important tools for understanding and communicating the spatial distribution of risks associated with natural hazards in regional economies. We present a GIS-based decision support system (DSS) for assessing community vulnerability to natural hazards and evaluating potential mitigation policy outcomes. The Land Use Portfolio Modeler (LUPM) integrates earth science and socioeconomic information to predict the economic impacts of loss-reduction strategies. However, the potential use of such systems in decision making may be limited when multiple but conflicting interpretations of the hazard are available. To explore this problem, we conduct a policy comparison using the LUPM to test the sensitivity of three available assessments of earthquake-induced lateral-spread ground failure susceptibility in a coastal California community. We find that the uncertainty regarding the interpretation of the science inputs can influence the development and implementation of natural hazard management policies. Copyright ?? 2006 Inderscience Enterprises Ltd.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"International Journal of Risk Assessment and Management","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1504/IJRAM.2006.009537","issn":"14668297","usgsCitation":"Bernknopf, R., Rabinovici, S., Wood, N., and Dinitz, L., 2006, The influence of hazard models on GIS-based regional risk assessments and mitigation policies: International Journal of Risk Assessment and Management, v. 6, no. 4-6, p. 369-387, https://doi.org/10.1504/IJRAM.2006.009537.","startPage":"369","endPage":"387","numberOfPages":"19","costCenters":[],"links":[{"id":210038,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1504/IJRAM.2006.009537"},{"id":236836,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"6","issue":"4-6","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505bad26e4b08c986b3239f7","contributors":{"authors":[{"text":"Bernknopf, R. L.","contributorId":46082,"corporation":false,"usgs":true,"family":"Bernknopf","given":"R. L.","affiliations":[],"preferred":false,"id":416429,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Rabinovici, S.J.M.","contributorId":103832,"corporation":false,"usgs":true,"family":"Rabinovici","given":"S.J.M.","affiliations":[],"preferred":false,"id":416430,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Wood, N.J.","contributorId":7900,"corporation":false,"usgs":true,"family":"Wood","given":"N.J.","email":"","affiliations":[],"preferred":false,"id":416427,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Dinitz, L.B.","contributorId":16192,"corporation":false,"usgs":true,"family":"Dinitz","given":"L.B.","email":"","affiliations":[],"preferred":false,"id":416428,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70028064,"text":"70028064 - 2006 - Comparing mean high water and high water line shorelines: Should prosy-datum offsets be incorporated into shoreline change analysis?","interactions":[],"lastModifiedDate":"2012-03-12T17:20:41","indexId":"70028064","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":2220,"text":"Journal of Coastal Research","active":true,"publicationSubtype":{"id":10}},"title":"Comparing mean high water and high water line shorelines: Should prosy-datum offsets be incorporated into shoreline change analysis?","docAbstract":"More than one type of shoreline indicator can be used in shoreline change analyses, and quantifying the effects of this practice on the resulting shoreline change rates is important. Comparison of three high water line (proxy-based) shorelines and a mean high water intercept (datum-based) shoreline collected from simultaneous aerial photographic and lidar surveys of a relatively steep reflective beach (tan ?? = 0.07), which experiences a moderately energetic wave climate (annual average Hs = 1.2 m), reveals an average horizontal offset of 18.8 m between the two types of shoreline indicators. Vertical offsets are also substantial and are correlated with foreshore beach slope and corresponding variations in wave runup. Incorporating the average horizontal offset into both a short-term, endpoint shoreline change analysis and a long-term, linear regression analysis causes rates to be shifted an average of -0.5 m/y and -0.1 m/y, respectively. The rate shift increases with increasing horizontal offset and decreasing measurement intervals and, depending on the rapidity of shoreline change rates, is responsible for varying degrees of analysis error. Our results demonstrate that under many circumstances, the error attributable to proxy-datum offsets is small relative to shoreline change rates and thus not important. Furthermore, we find that when the error associated with proxy-datum offsets is large enough to be important, the shoreline change rates themselves are not likely to be significant. A total water level model reveals that the high water line digitized by three independent coastal labs for this study was generated by a combination of large waves and a high tide several days before the collection of aerial photography. This illustrates the complexity of the high water line as a shoreline indicator and calls into question traditional definitions, which consider the high water line a wetted bound or \"marks left by the previous high tide.\".","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Coastal Research","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.2112/04-0401.1","issn":"07490208","usgsCitation":"Moore, L.J., Ruggiero, P., and List, J.H., 2006, Comparing mean high water and high water line shorelines: Should prosy-datum offsets be incorporated into shoreline change analysis?: Journal of Coastal Research, v. 22, no. 4, p. 894-905, https://doi.org/10.2112/04-0401.1.","startPage":"894","endPage":"905","numberOfPages":"12","costCenters":[],"links":[{"id":210280,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.2112/04-0401.1"},{"id":237155,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"22","issue":"4","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f836e4b0c8380cd4cf4b","contributors":{"authors":[{"text":"Moore, L. J.","contributorId":53132,"corporation":false,"usgs":false,"family":"Moore","given":"L.","email":"","middleInitial":"J.","affiliations":[],"preferred":false,"id":416386,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ruggiero, P.","contributorId":25995,"corporation":false,"usgs":true,"family":"Ruggiero","given":"P.","affiliations":[],"preferred":false,"id":416385,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"List, J. H.","contributorId":70406,"corporation":false,"usgs":true,"family":"List","given":"J.","email":"","middleInitial":"H.","affiliations":[],"preferred":false,"id":416387,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
,{"id":70030637,"text":"70030637 - 2006 - Inverse modeling for seawater intrusion in coastal aquifers: Insights about parameter sensitivities, variances, correlations and estimation procedures derived from the Henry problem","interactions":[],"lastModifiedDate":"2018-10-22T10:57:04","indexId":"70030637","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","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":"Inverse modeling for seawater intrusion in coastal aquifers: Insights about parameter sensitivities, variances, correlations and estimation procedures derived from the Henry problem","docAbstract":"<p>Inverse modeling studies employing data collected from the classic Henry seawater intrusion problem give insight into several important aspects of inverse modeling of seawater intrusion problems and effective measurement strategies for estimation of parameters for seawater intrusion. Despite the simplicity of the Henry problem, it embodies the behavior of a typical seawater intrusion situation in a single aquifer. Data collected from the numerical problem solution are employed without added noise in order to focus on the aspects of inverse modeling strategies dictated by the physics of variable-density flow and solute transport during seawater intrusion. Covariances of model parameters that can be estimated are strongly dependent on the physics. The insights gained from this type of analysis may be directly applied to field problems in the presence of data errors, using standard inverse modeling approaches to deal with uncertainty in data.</p><p>Covariance analysis of the Henry problem indicates that in order to generally reduce variance of parameter estimates, the ideal places to measure pressure are as far away from the coast as possible, at any depth, and the ideal places to measure concentration are near the bottom of the aquifer between the center of the transition zone and its inland fringe. These observations are located in and near high-sensitivity regions of system parameters, which may be identified in a sensitivity analysis with respect to several parameters. However, both the form of error distribution in the observations and the observation weights impact the spatial sensitivity distributions, and different choices for error distributions or weights can result in significantly different regions of high sensitivity. Thus, in order to design effective sampling networks, the error form and weights must be carefully considered. For the Henry problem, permeability and freshwater inflow can be estimated with low estimation variance from only pressure or only concentration observations. Permeability, freshwater inflow, solute molecular diffusivity, and porosity can be estimated with roughly equivalent confidence using observations of only the logarithm of concentration. Furthermore, covariance analysis allows a logical reduction of the number of estimated parameters for ill-posed inverse seawater intrusion problems. Ill-posed problems may exhibit poor estimation convergence, have a non-unique solution, have multiple minima, or require excessive computational effort, and the condition often occurs when estimating too many or co-dependent parameters. For the Henry problem, such analysis allows selection of the two parameters that control system physics from among all possible system parameters.</p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.advwatres.2005.05.014","issn":"03091708","usgsCitation":"Sanz, E., and Voss, C., 2006, Inverse modeling for seawater intrusion in coastal aquifers: Insights about parameter sensitivities, variances, correlations and estimation procedures derived from the Henry problem: Advances in Water Resources, v. 29, no. 3, p. 439-457, https://doi.org/10.1016/j.advwatres.2005.05.014.","productDescription":"19 p.","startPage":"439","endPage":"457","costCenters":[{"id":589,"text":"Toxic Substances Hydrology Program","active":true,"usgs":true}],"links":[{"id":239388,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":211991,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.advwatres.2005.05.014"}],"volume":"29","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a3e4ce4b0c8380cd63c6d","contributors":{"authors":[{"text":"Sanz, E.","contributorId":49181,"corporation":false,"usgs":true,"family":"Sanz","given":"E.","email":"","affiliations":[],"preferred":false,"id":427975,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Voss, C.I.","contributorId":79515,"corporation":false,"usgs":true,"family":"Voss","given":"C.I.","email":"","affiliations":[],"preferred":false,"id":427976,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70028507,"text":"70028507 - 2006 - Application of artificial neural networks to assess pesticide contamination in shallow groundwater","interactions":[],"lastModifiedDate":"2012-03-12T17:20:43","indexId":"70028507","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","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":"Application of artificial neural networks to assess pesticide contamination in shallow groundwater","docAbstract":"In this study, a feed-forward back-propagation neural network (BPNN) was developed and applied to predict pesticide concentrations in groundwater monitoring wells. Pesticide concentration data are challenging to analyze because they tend to be highly censored. Input data to the neural network included the categorical indices of depth to aquifer material, pesticide leaching class, aquifer sensitivity to pesticide contamination, time (month) of sample collection, well depth, depth to water from land surface, and additional travel distance in the saturated zone (i.e., distance from land surface to midpoint of well screen). The output of the neural network was the total pesticide concentration detected in the well. The model prediction results produced good agreements with observed data in terms of correlation coefficient (R = 0.87) and pesticide detection efficiency (E = 89%), as well as good match between the observed and predicted \"class\" groups. The relative importance of input parameters to pesticide occurrence in groundwater was examined in terms of R, E, mean error (ME), root mean square error (RMSE), and pesticide occurrence \"class\" groups by eliminating some key input parameters to the model. Well depth and time of sample collection were the most sensitive input parameters for predicting the pesticide contamination potential of a well. This infers that wells tapping shallow aquifers are more vulnerable to pesticide contamination than those wells tapping deeper aquifers. Pesticide occurrences during post-application months (June through October) were found to be 2.5 to 3 times higher than pesticide occurrences during other months (November through April). The BPNN was used to rank the input parameters with highest potential to contaminate groundwater, including two original and five ancillary parameters. The two original parameters are depth to aquifer material and pesticide leaching class. When these two parameters were the only input parameters for the BPNN, they were not able to predict contamination potential. However, when they were used with other parameters, the predictive performance efficiency of the BPNN in terms of R, E, ME, RMSE, and pesticide occurrence \"class\" groups increased. Ancillary data include data collected during the study such as well depth and time of sample collection. The BPNN indicated that the ancillary data had more predictive power than the original data. The BPNN results will help researchers identify parameters to improve maps of aquifer sensitivity to pesticide contamination. ?? 2006 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Science of the Total Environment","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.scitotenv.2005.12.011","issn":"00489697","usgsCitation":"Sahoo, G., Ray, C., Mehnert, E., and Keefer, D., 2006, Application of artificial neural networks to assess pesticide contamination in shallow groundwater: Science of the Total Environment, v. 367, no. 1, p. 234-251, https://doi.org/10.1016/j.scitotenv.2005.12.011.","startPage":"234","endPage":"251","numberOfPages":"18","costCenters":[],"links":[{"id":477506,"rank":10000,"type":{"id":40,"text":"Open Access Publisher Index Page"},"url":"https://doi.org/10.1016/j.scitotenv.2005.12.011","text":"Publisher Index Page"},{"id":209861,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.scitotenv.2005.12.011"},{"id":236598,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"367","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059ec96e4b0c8380cd49373","contributors":{"authors":[{"text":"Sahoo, G.B.","contributorId":49167,"corporation":false,"usgs":true,"family":"Sahoo","given":"G.B.","email":"","affiliations":[],"preferred":false,"id":418370,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Ray, C.","contributorId":40758,"corporation":false,"usgs":true,"family":"Ray","given":"C.","email":"","affiliations":[],"preferred":false,"id":418369,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Mehnert, E.","contributorId":64830,"corporation":false,"usgs":true,"family":"Mehnert","given":"E.","email":"","affiliations":[],"preferred":false,"id":418371,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Keefer, D.A.","contributorId":90890,"corporation":false,"usgs":true,"family":"Keefer","given":"D.A.","email":"","affiliations":[],"preferred":false,"id":418372,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":70030334,"text":"70030334 - 2006 - Comparative performance of fixed-film biological filters: Application of reactor theory","interactions":[],"lastModifiedDate":"2012-03-12T17:21:11","indexId":"70030334","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":852,"text":"Aquacultural Engineering","active":true,"publicationSubtype":{"id":10}},"title":"Comparative performance of fixed-film biological filters: Application of reactor theory","docAbstract":"Nitrification is classified as a two-step consecutive reaction where R1 represents the rate of formation of the intermediate product NO2-N and R2 represents the rate of formation of the final product NO3-N. The relative rates of R1 and R2 are influenced by reactor type characterized hydraulically as plug-flow, plug-flow with dispersion and mixed-flow. We develop substrate conversion models for fixed-film biofilters operating in the first-order kinetic regime based on application of chemical reactor theory. Reactor type, inlet conditions and the biofilm kinetic constants Ki (h-1) are used to predict changes in NH4-N, NO2-N, NO3-N and BOD5. The inhibiting effects of the latter on R1 and R2 were established based on the ?? relation, e.g.:{A formula is presented}where BOD5,max is the concentration that causes nitrification to cease and N is a variable relating Ki to increasing BOD5. Conversion models were incorporated in spreadsheet programs that provided steady-state concentrations of nitrogen and BOD5 at several points in a recirculating aquaculture system operating with input values for fish feed rate, reactor volume, microscreen performance, make-up and recirculating flow rates. When rate constants are standardized, spreadsheet use demonstrates plug-flow reactors provide higher rates of R1 and R2 than mixed-flow reactors thereby reducing volume requirements for target concentrations of NH4-N and NO2-N. The benefit provided by the plug-flow reactor varies with hydraulic residence time t as well as the effective vessel dispersion number, D/??L. Both reactor types are capable of providing net increases in NO2-N during treatment but the rate of decrease in the mixed-flow case falls well behind that predicted for plug-flow operation. We show the potential for a positive net change in NO2-N increases with decreases in the dimensionless ratios K2, (R2 )/K1,( R1 ) and [NO2-N]/[NH4-N] and when the product K1, (R1) t provides low to moderate NH4-N conversions. Maintaining high levels of the latter reduces the effective reactor utilization rate (%) defined here as (RNavg/RNmax)100 where RNavg is the mean reactive nitrogen concentration ([NH4-N] + [NO2-N]) within the reactor, and RNmax represents the feed concentration of the same. Low utilization rates provide a hedge against unexpected increases in substrate loading and reduce water pumping requirements but force use of elevated reactor volumes. Further ?? effects on R1 and R2 can be reduced through use of a tanks-in-series versus a single mixed-flow reactor configuration and by improving the solids removal efficiency of microscreen treatment.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Aquacultural Engineering","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.aquaeng.2005.03.006","issn":"01448609","usgsCitation":"Watten, B., and Sibrell, P., 2006, Comparative performance of fixed-film biological filters: Application of reactor theory: Aquacultural Engineering, v. 34, no. 3, p. 198-213, https://doi.org/10.1016/j.aquaeng.2005.03.006.","startPage":"198","endPage":"213","numberOfPages":"16","costCenters":[],"links":[{"id":212145,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.aquaeng.2005.03.006"},{"id":239582,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"34","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059f821e4b0c8380cd4cecd","contributors":{"authors":[{"text":"Watten, B.J. 0000-0002-2227-8623","orcid":"https://orcid.org/0000-0002-2227-8623","contributorId":11537,"corporation":false,"usgs":true,"family":"Watten","given":"B.J.","affiliations":[{"id":365,"text":"Leetown Science Center","active":true,"usgs":true}],"preferred":false,"id":426733,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Sibrell, P.L.","contributorId":13343,"corporation":false,"usgs":true,"family":"Sibrell","given":"P.L.","affiliations":[],"preferred":false,"id":426734,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70030282,"text":"70030282 - 2006 - A plastic flow model for the Acquara - Vadoncello landslide in Senerchia, Southern Italy","interactions":[],"lastModifiedDate":"2012-03-12T17:21:02","indexId":"70030282","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":1517,"text":"Engineering Geology","active":true,"publicationSubtype":{"id":10}},"title":"A plastic flow model for the Acquara - Vadoncello landslide in Senerchia, Southern Italy","docAbstract":"A previously developed model for stress and velocity fields in two-dimensional Coulomb plastic materials under self-weight and pore pressure predicts that long, shallow landslides develop slip surfaces that manifest themselves as normal faults and normal fault scarps at the surface in areas of extending flow and as thrust faults and thrust fault scarps at the surface in areas of compressive flow. We have applied this model to describe the geometry of slip surfaces and ground stresses developed during the 1995 reactivation of the Acquara - Vadoncello landslide in Senerchia, southern Italy. This landslide is a long and shallow slide in which regions of compressive and extending flow are clearly identified. Slip surfaces in the main scarp region of the landslide have been reconstructed using surface surveys and subsurface borehole logging and inclinometer observations made during retrogression of the main scarp. Two of the four inferred main scarp slip surfaces are best constrained by field data. Slip surfaces in the toe region are reconstructed in the same way and three of the five inferred slip surfaces are similarly constrained. The location of the basal shear surface of the landslide is inferred from borehole logging and borehole inclinometry. Extensive data on material properties, landslide geometries, and pore pressures collected for the Acquara - Vadoncello landslide give values for cohesion, friction angle, and unit weight, plus average basal shear-surface slopes, and pore-pressures required for modelling slip surfaces and stress fields. Results obtained from the landslide-flow model and the field data show that predicted slip surface shapes are consistent with inferred slip surface shapes in both the extending flow main scarp region and in the compressive flow toe region of the Acquara - Vadoncello landslide. Also predicted stress distributions are found to explain deformation features seen in the toe and main scarp regions of the landslide. ?? 2005 Elsevier B.V. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Engineering Geology","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.enggeo.2005.06.024","issn":"00137952","usgsCitation":"Savage, W., and Wasowski, J., 2006, A plastic flow model for the Acquara - Vadoncello landslide in Senerchia, Southern Italy: Engineering Geology, v. 83, no. 1-3, p. 4-21, https://doi.org/10.1016/j.enggeo.2005.06.024.","startPage":"4","endPage":"21","numberOfPages":"18","costCenters":[],"links":[{"id":211916,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.enggeo.2005.06.024"},{"id":239297,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"83","issue":"1-3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e4dce4b0c8380cd469a8","contributors":{"authors":[{"text":"Savage, W.","contributorId":8675,"corporation":false,"usgs":true,"family":"Savage","given":"W.","affiliations":[],"preferred":false,"id":426472,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Wasowski, J.","contributorId":18974,"corporation":false,"usgs":true,"family":"Wasowski","given":"J.","email":"","affiliations":[],"preferred":false,"id":426473,"contributorType":{"id":1,"text":"Authors"},"rank":2}]}}
,{"id":70028569,"text":"70028569 - 2006 - A 16-year record of eolian dust in Southern Nevada and California, USA: Controls on dust generation and accumulation","interactions":[],"lastModifiedDate":"2012-03-12T17:20:59","indexId":"70028569","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","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":"A 16-year record of eolian dust in Southern Nevada and California, USA: Controls on dust generation and accumulation","docAbstract":"An ongoing project monitors modern dust accumulation in the arid southwestern United States to (1) determine the rate and composition of dust inputs to soils and (2) relate dust accumulation to weather patterns to help predict the effects of climate change on dust production and accumulation. The 16-year records of 35 dust-trap sites in the eastern Mojave Desert and southern Great Basin reveal how generation and accumulation of dust, including the silt-clay, carbonate, and soluble-salt fractions, is affected by the amount and seasonal distribution of rainfall and the behavior of different source types (alluvium, dry playas, and wet playas). Accumulation rates (fluxes) of the silt-clay fraction of dust, including carbonates, range from about 2-20 g/m2/yr. Average rates are higher in the southern part of the study area (south of latitude 36.5??N) and annually fluctuate over a larger range than rates in the northern part of the area. Sites throughout the study area show peaks in dust flux in the 1984-1985 sampling period and again in 1997-1999; northern sites also show increased flux in 1987-1988 and southern sites in 1989-1991. These peaks of dust flux correspond with both La Nina (dry) conditions and with strong El Nino (wet) periods. The accumulation rates of different components of mineral dusts fluctuate differently. For example, soluble-salt flux increases in 1987-1988, coincident with a moderate El Nino event, and increases very strongly in 1997-1999, overlapping with a strong El Nino event. Both of these high-rainfall winters were preceded and accompanied by strong summer rains. In contrast, little or no change in soluble-salt flux occurred during other periods of high winter rainfall but little summer rain, e.g. 1992-1995. The differences between northern vs. southern sites and between sites with playa dust sources vs. alluvial dust sources indicate that regional differences in the response of precipitation and vegetation growth to ENSO influence and differences in the response of source types control dust production and accumulation. A major factor is the hydrologic condition of surface sediments. The silt-clay and soluble-salt fluxes increased during the El Nino events of 1987-1988 and 1997-1998 at sites close to \"wet\" playas with shallow depths to groundwater (<10 m), consistent with the concept that active evaporative concentration of salts disrupts surface crusts and increases the susceptibility of surface sediment to deflation. The silt-clay flux also increased during drought periods (1989-1991, 1995-1997) at sites downwind of alluvial sources and \"dry\" playas with deeper groundwater (<10 m). These increases are probably related to the die-off of drought-stressed vegetation on alluvial sediments, and in some cases to local runoff events that deliver fresh sediment to playa margins and distal portions of alluvial fans. ?? 2006 Elsevier Ltd. All rights reserved.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Journal of Arid Environments","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","doi":"10.1016/j.jaridenv.2006.03.006","issn":"01401963","usgsCitation":"Reheis, M., 2006, A 16-year record of eolian dust in Southern Nevada and California, USA: Controls on dust generation and accumulation: Journal of Arid Environments, v. 67, no. 3, p. 487-520, https://doi.org/10.1016/j.jaridenv.2006.03.006.","startPage":"487","endPage":"520","numberOfPages":"34","costCenters":[],"links":[{"id":209811,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.jaridenv.2006.03.006"},{"id":236534,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"}],"volume":"67","issue":"3","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"5059e2c0e4b0c8380cd45c0a","contributors":{"authors":[{"text":"Reheis, M.C. 0000-0002-8359-323X","orcid":"https://orcid.org/0000-0002-8359-323X","contributorId":36128,"corporation":false,"usgs":true,"family":"Reheis","given":"M.C.","affiliations":[],"preferred":false,"id":418649,"contributorType":{"id":1,"text":"Authors"},"rank":1}]}}
,{"id":70028856,"text":"70028856 - 2006 - Experiments on δ<sup>34</sup>S  mixing between organic and inorganic sulfur species during thermal maturation","interactions":[],"lastModifiedDate":"2015-04-20T12:05:48","indexId":"70028856","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","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":"Experiments on δ<sup>34</sup>S  mixing between organic and inorganic sulfur species during thermal maturation","docAbstract":"<p>Reduced sulfur species were studied to constrain isotopic exchange-mixing with synthetic polysulfide cross-linked macromolecules (PCLM), model sulfur containing molecules and natural sulfur-rich kerogen, asphalt and oil of the Dead Sea area. PCLM represents protokerogens that are rich in sulfur and thermally unstable. Mixing rates of PCLM with <span id=\"mmlsi1\" class=\"mathmlsrc\"><a class=\"mathImg\" title=\"View the MathML source\" data-mathurl=\"/science?_ob=MathURL&amp;_method=retrieve&amp;_eid=1-s2.0-S0016703706019600&amp;_mathId=si1.gif&amp;_user=111111111&amp;_pii=S0016703706019600&amp;_rdoc=1&amp;_issn=00167037&amp;md5=461fee51a090a11d0ac85e0362eb7d8d\"><img class=\"imgLazyJSB inlineImage\" title=\"View the MathML source\" src=\"http://ars.els-cdn.com/content/image/1-s2.0-S0016703706019600-si1.gif\" alt=\"View the MathML source\" width=\"54\" height=\"20\" data-loaded=\"true\" data-inlimgeid=\"1-s2.0-S0016703706019600-si1.gif\" /></a><span class=\"mathContainer hidden\"><span class=\"mathCode\">HS-(aq)</span></span></span> (added as (NH<sub>4</sub>)<sub>2</sub>S<sub>(aq)</sub>) at low to moderate temperatures (50&ndash;200&nbsp;&deg;C) are rapid. Elemental sulfur and H<sub>2</sub>S<sub>(gas)</sub> fully mix isotopes with PCLM during pyrolysis conditions at 200&nbsp;&deg;C. During these reactions significant structural changes of the PCLM occur to form polysulfide dimers, thiolanes and thiophenes. As pyrolysis temperatures or reaction times increase, the PCLM thermal products are transformed to more aromatic sulfur compounds. Isotopic mixing rates increase with increasing pyrolysis temperature and time. Polysulfide bonds (S&ndash;S) in the PCLM are responsible for most of these structural and isotopic changes because of their low stability. Conversely, sulfur isotope mixing does not occur between dibenzothiophene (aromatic S) or hexadecanthiol (C&ndash;SH) and <span id=\"mmlsi2\" class=\"mathmlsrc\"><a class=\"mathImg\" title=\"View the MathML source\" data-mathurl=\"/science?_ob=MathURL&amp;_method=retrieve&amp;_eid=1-s2.0-S0016703706019600&amp;_mathId=si2.gif&amp;_user=111111111&amp;_pii=S0016703706019600&amp;_rdoc=1&amp;_issn=00167037&amp;md5=211d530a03d9601f5607a4e90d3d2755\"><img class=\"imgLazyJSB inlineImage\" title=\"View the MathML source\" src=\"http://ars.els-cdn.com/content/image/1-s2.0-S0016703706019600-si2.gif\" alt=\"View the MathML source\" width=\"54\" height=\"20\" data-loaded=\"true\" data-inlimgeid=\"1-s2.0-S0016703706019600-si2.gif\" /></a><span class=\"mathContainer hidden\"><span class=\"mathCode\">HS-(aq)</span></span></span> at 200&nbsp;&deg;C after 48&nbsp;h. This shows that rates of sulfur isotope mixing are strongly dependent on the functionality of the sulfur in the organic matter. The order of isotopic mixing rates for organic matter is kerogen&nbsp;&gt;&nbsp;asphalt&nbsp;&gt;&nbsp;oil, which is inverse to their sulfur thermal stability. Asphalt and oil with more refractory sulfur show significantly lower isotopes mixing rates than the kerogen with more labile sulfur. Based on the findings of the present study we suggest that sulfur isotopes mixing can occur from early diagenesis into catagenesis and result in isotopic homogenization of the inorganic and organic reduced sulfur pools.</p>","language":"English","publisher":"Elsevier","doi":"10.1016/j.gca.2006.07.030","issn":"00167037","usgsCitation":"Amrani, A., Said-Ahamed, W., Lewan, M., and Aizenshtat, Z., 2006, Experiments on δ<sup>34</sup>S  mixing between organic and inorganic sulfur species during thermal maturation: Geochimica et Cosmochimica Acta, v. 70, no. 20, p. 5146-5161, https://doi.org/10.1016/j.gca.2006.07.030.","productDescription":"16 p.","startPage":"5146","endPage":"5161","onlineOnly":"N","additionalOnlineFiles":"N","costCenters":[],"links":[{"id":236483,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":209774,"rank":9999,"type":{"id":10,"text":"Digital Object Identifier"},"url":"https://dx.doi.org/10.1016/j.gca.2006.07.030"}],"volume":"70","issue":"20","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"505a0dfde4b0c8380cd53265","contributors":{"authors":[{"text":"Amrani, Alon","contributorId":49258,"corporation":false,"usgs":true,"family":"Amrani","given":"Alon","email":"","affiliations":[],"preferred":false,"id":420040,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Said-Ahamed, Ward","contributorId":25740,"corporation":false,"usgs":true,"family":"Said-Ahamed","given":"Ward","email":"","affiliations":[],"preferred":false,"id":420038,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"Lewan, Michael D. mlewan@usgs.gov","contributorId":940,"corporation":false,"usgs":true,"family":"Lewan","given":"Michael D.","email":"mlewan@usgs.gov","affiliations":[{"id":164,"text":"Central Energy Resources Science Center","active":true,"usgs":true}],"preferred":false,"id":420039,"contributorType":{"id":1,"text":"Authors"},"rank":3},{"text":"Aizenshtat, Zeev","contributorId":21747,"corporation":false,"usgs":true,"family":"Aizenshtat","given":"Zeev","email":"","affiliations":[],"preferred":false,"id":420037,"contributorType":{"id":1,"text":"Authors"},"rank":4}]}}
,{"id":1003348,"text":"1003348 - 2006 - Response of fishes to floodplain connectivity during and following a 500-year flood event in the unimpounded upper Mississippi River","interactions":[],"lastModifiedDate":"2012-02-02T00:04:48","indexId":"1003348","displayToPublicDate":"2006-01-01T00:00:00","publicationYear":"2006","noYear":false,"publicationType":{"id":2,"text":"Article"},"publicationSubtype":{"id":10,"text":"Journal Article"},"seriesTitle":{"id":3750,"text":"Wetlands","onlineIssn":"1943-6246","printIssn":"0277-5212","active":true,"publicationSubtype":{"id":10}},"title":"Response of fishes to floodplain connectivity during and following a 500-year flood event in the unimpounded upper Mississippi River","docAbstract":"We examined data collected on fish assemblage structure among three differing floodplain types (broad, moderate, and narrow) during the 1993 flood in the unimpounded reach of the upper Mississippi River. This 500 year flood event provided a unique opportunity to investigate fish-floodplain function because the main river channel is otherwise typically disjunct from approximately 82% of its floodplain by an extensive levee system. Fishes were sampled during three separate periods, and 42 species of adult and young-of-the-year (YOY) fishes were captured. Analysis of similarity (ANOSIM) revealed a significant and distinguishable difference between both adult and YOY assemblage structure among the three floodplain types. Analysis of variance revealed that Secchi transparency, turbidity, water velocity, and dissolved oxygen were significantly different among the floodplain types. However, only depth of gear deployment and Secchi transparency were significantly correlated with adult assemblage structure. None of these variables were significantly correlated with YOY assemblage structure. The numerically abundant families (adult and YOY catches combined) on the floodplain included Centrarchidae, Ictularidae, and Cyprinidae. Both native and non-native fishes were captured on the floodplain, and several of the numerically abundant species that were captured on the floodplain peaked in catch-per-unit-effort 1-3 years after the 1993 flood event. This suggests that some species may have used flooded terrestrial habitat for spawning, feeding, or both. The findings from our study provide much needed insight into fish-floodplain function in a temperate, channelized river system and suggest that lateral connectivity of the main river channel to less degraded reaches of its floodplain should become a management priority not only to maintain faunal biodiversity but also potentially reduce the impacts of non-native species in large river systems.","largerWorkType":{"id":2,"text":"Article"},"largerWorkTitle":"Wetlands","largerWorkSubtype":{"id":10,"text":"Journal Article"},"language":"English","usgsCitation":"Barko, V., Herzog, D., and O’Connell, M.T., 2006, Response of fishes to floodplain connectivity during and following a 500-year flood event in the unimpounded upper Mississippi River: Wetlands, v. 26, no. 1, p. 244-257.","productDescription":"pp. 244-257","startPage":"244","endPage":"257","numberOfPages":"14","costCenters":[{"id":606,"text":"Upper Midwest Environmental Sciences Center","active":true,"usgs":true}],"links":[{"id":133885,"rank":0,"type":{"id":24,"text":"Thumbnail"},"url":"https://pubs.usgs.gov/thumbnails/outside_thumb.jpg"},{"id":15585,"rank":100,"type":{"id":15,"text":"Index Page"},"url":"https://www.bioone.org/doi/abs/10.1672/0277-5212%282006%2926%5B244%3AROFTFC%5D2.0.CO%3B2","linkFileType":{"id":5,"text":"html"},"description":"4356.000000000000000"}],"volume":"26","issue":"1","noUsgsAuthors":false,"publicationStatus":"PW","scienceBaseUri":"4f4e4a51e4b07f02db629bf1","contributors":{"authors":[{"text":"Barko, V.A.","contributorId":75477,"corporation":false,"usgs":true,"family":"Barko","given":"V.A.","email":"","affiliations":[],"preferred":false,"id":313139,"contributorType":{"id":1,"text":"Authors"},"rank":1},{"text":"Herzog, D.P.","contributorId":103218,"corporation":false,"usgs":true,"family":"Herzog","given":"D.P.","email":"","affiliations":[],"preferred":false,"id":313140,"contributorType":{"id":1,"text":"Authors"},"rank":2},{"text":"O’Connell, M. T.","contributorId":105679,"corporation":false,"usgs":true,"family":"O’Connell","given":"M.","email":"","middleInitial":"T.","affiliations":[],"preferred":false,"id":313141,"contributorType":{"id":1,"text":"Authors"},"rank":3}]}}
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