Identifying calcium sources at an acid deposition-impacted spruce forest: A strontium isotope, alkaline earth element multi-tracer approach
T.D. Bullen, S.W. Bailey
2005, Biogeochemistry (74) 63-99
Depletion of calcium from forest soils has important implications for forest productivity and health. Ca is available to fine feeder roots from a number of soil organic and mineral sources, but identifying the primary source or changes of sources in response to environmental change is problematic. We used strontium...
Heat as a tracer to estimate dissolved organic carbon flux from a restored wetland
K.R. Burow, J. Constantz, R. Fujii
2005, Ground Water (43) 545-556
Heat was used as a natural tracer to characterize shallow ground water flow beneath a complex wetland system. Hydrogeologic data were combined with measured vertical temperature profiles to constrain a series of two‐dimensional, transient simulations of ground water flow and heat transport using the model code...
Climate anomalies generate an exceptional dinoflagellate bloom in San Francisco Bay
J. E. Cloern, T.S. Schraga, C.B. Lopez, N. Knowles, Labiosa R. Grover, R. Dugdale
2005, Geophysical Research Letters (32) 1-5
We describe a large dinoflagellate bloom, unprecedented in nearly three decades of observation, that developed in San Francisco Bay (SFB) during September 2004. SFB is highly enriched in nutrients but has low summer‐autumn algal biomass because wind stress and tidally induced bottom stress produce a well mixed and light‐limited pelagic...
Assessing the vulnerability of a municipal well field to contamination in a karst aquifer
R.A. Renken, K.J. Cunningham, M.R. Zygnerski, M.A. Wacker, A.M. Shapiro, R.W. Harvey, D.W. Metge, C.L. Osborn, J. N. Ryan
2005, Environmental & Engineering Geoscience (11) 319-331
Proposed expansion of extractive lime-rock mines near the Miami-Dade County Northwest well field and Everglades wetland areas has garnered intense scrutiny by government, public, environmental stakeholders, and the media because of concern that mining will increase the risk of pathogen contamination. Rock mines are excavated to the same depth as...
Simulation of integrated surface-water/ground-water flow and salinity for a coastal wetland and adjacent estuary
C. Langevin, E. Swain, M. Wolfert
2005, Journal of Hydrology (314) 212-234
The SWIFT2D surface-water flow and transport code, which solves the St Venant equations in two dimensions, was coupled with the SEAWAT variable-density ground-water code to represent hydrologic processes in coastal wetlands and adjacent estuaries. A sequentially coupled time-lagged approach was implemented, based on a variable-density form of Darcy's Law, to...
A simple method for calculating growth rates of petroleum hydrocarbon plumes
B.A. Bekins, I.M. Cozzarelli, G.P. Curtis
2005, Ground Water (43) 817-826
Consumption of aquifer Fe(III) during biodegradation of ground water contaminants may result in expansion of a contaminant plume, changing the outlook for monitored natural attenuation. Data from two research sites contaminated with petroleum hydrocarbons show that toluene and xylenes degrade under methanogenic conditions, but the benzene...
Repeated surveys by acoustic Doppler current profiler for flow and sediment dynamics in a tidal river
R.L. Dinehart, J.R. Burau
2005, Journal of Hydrology (314) 1-21
A strategy of repeated surveys by acoustic Doppler current profiler (ADCP) was applied in a tidal river to map velocity vectors and suspended-sediment indicators. The Sacramento River at the junction with the Delta Cross Channel at Walnut Grove, California, was surveyed over several tidal cycles in the Fall of 2000...
Modeling and measuring the nocturnal drainage flow in a high-elevation, subalpine forest with complex terrain
C. Yi, Russell K. Monson, Z. Zhai, D.E. Anderson, B. Lamb, G. Allwine, A.A. Turnipseed, Sean P. Burns
2005, Journal of Geophysical Research D: Atmospheres (110) 1-13
The nocturnal drainage flow of air causes significant uncertainty in ecosystem CO2, H2O, and energy budgets determined with the eddy covariance measurement approach. In this study, we examined the magnitude, nature, and dynamics of the nocturnal drainage flow in a subalpine forest ecosystem with complex terrain. We used an experimental...
Nonlinear regression modeling of nutrient loads in streams: A Bayesian approach
Song S. Qian, Kenneth H. Reckhow, Jun Zhai, Gerard McMahon
2005, Water Resources Research (41)
A Bayesian nonlinear regression modeling method is introduced and compared with the least squares method for modeling nutrient loads in stream networks. The objective of the study is to better model spatial correlation in river basin hydrology and land use for improving the model as a forecasting tool. The Bayesian...
Spatial and temporal variability in the amount and source of dissolved organic carbon: Implications for ultraviolet exposure in amphibian habitats
P. D. Brooks, C. M. O’Reilly, S. A. Diamond, K. Campbell, R. Knapp, D. Bradford, P.S. Corn, B. Hossack, K. Tonnessen
2005, Ecosystems (8) 478-487
The amount, chemical composition, and source of dissolved organic carbon (DOC), together with in situ ultraviolet (UV-B) attenuation, were measured at 1–2 week intervals throughout the summers of 1999, 2000, and 2001 at four sites in Rocky Mountain National Park (Colorado). Eight additional sites, four in Sequoia and Kings Canyon...
Small-scale, hydrogen-oxidizing-denitrifying bioreactor for treatment of nitrate-contaminated drinking water
R. L. Smith, S.P. Buckwalter, D.A. Repert, D.N. Miller
2005, Water Research (39) 2014-2023
Nitrate removal by hydrogen-coupled denitrification was examined using flow-through, packed-bed bioreactors to develop a small-scale, cost effective system for treating nitrate-contaminated drinking-water supplies. Nitrate removal was accomplished using a Rhodocyclus sp., strain HOD 5, isolated from a sole-source drinking-water aquifer. The autotrophic capacity of the purple non-sulfur photosynthetic bacterium made...
Quasi‐steady centrifuge method for unsaturated hydraulic properties
Maria C. Caputo, John R. Nimmo
2005, Water Resources Research (41)
We have developed the quasi‐steady centrifuge (QSC) method as a variation of the steady state centrifuge method that can be implemented simply and inexpensively with greater versatility in terms of sample size and other features. It achieves these advantages by somewhat relaxing the criterion for steadiness of flow through the...
Provenance and diagenesis of the evaporite-bearing Burns formation, Meridiani Planum, Mars
S. M. McLennan, J.F. Bell III, W. M. Calvin, P. R. Christensen, B.C. Clark, P.A. de Souza, J. Farmer, W. H. Farrand, D.A. Fike, Ralf Gellert, A. Ghosh, T.D. Glotch, J.P. Grotzinger, B. Hahn, Kenneth E. Herkenhoff, J.A. Hurowitz, J. R. Johnson, S.S. Johnson, B. Jolliff, G. Klingelhofer, A.H. Knoll, Z. Learner, M. C. Malin, H.Y. McSween Jr., J. Pocock, S. W. Ruff, Laurence A. Soderblom, S. W. Squyres, N.J. Tosca, W.A. Watters, M.B. Wyatt, A. Yen
2005, Earth and Planetary Science Letters (240) 95-121
Impure reworked evaporitic sandstones, preserved on Meridiani Planum, Mars, are mixtures of roughly equal amounts of altered siliciclastic debris, of basaltic provenance (40 ± 10% by mass), and chemical constituents, dominated by evaporitic minerals (jarosite, Mg-, Ca-sulfates ± chlorides ± Fe-, Na-sulfates), hematite and possibly secondary silica (60 ± 10%). These chemical constituents and their relative abundances are...
Loosely bound oxytetracycline in riverine sediments from two tributaries of the Chesapeake Bay
N.S. Simon
2005, Environmental Science & Technology (39) 3480-3487
The fate of antibiotics that bind to riverine sediment is not well understood. A solution used in geochemical extraction schemes to determine loosely bound species in sediments, 1 M MgCl2 (pH 8), was chosen to determine loosely bound, and potentially bioavailable, tetracycline antibiotics (TCs), including oxytetracycline (5-OH tetracycline)...
Decadal-scale change of infiltration characteristics of a tephra-mantled hillslope at Mount St Helens, Washington
J. J. Major, T. Yamakoshi
2005, Hydrological Processes (19) 3621-3630
The cataclysmic 1980 eruption of Mount St Helens radically reduced the infiltration characteristics of ∼60 000 ha of rugged terrain and dramatically altered landscape hydrology. Two decades of erosional, biogenic, cryogenic, and anthropogenic activity have modified the infiltration characteristics of much of that devastated landscape and modulated the hydrological impact...
Transport and fate of nitrate and pesticides: Hydrogeology and riparian zone processes
L.J. Puckett, W.B. Hughes
2005, Journal of Environmental Quality (34) 2278-2292
There is continuing concern over potential impacts of widespread application of nutrients and pesticides on ground- and surface-water quality. Transport and fate of nitrate and pesticides were investigated in a shallow aquifer and adjacent stream, Cow Castle Creek, in Orangeburg County, South Carolina. Pesticide and pesticide degradate concentrations were detected...
Coupled inverse modeling of vadose zone water, heat, and solute transport: Calibration constraints, parameter nonuniqueness, and predictive uncertainty
M.J. Friedel
2005, Journal of Hydrology (312) 148-175
In this study, an inverse methodology is presented and used to evaluate the effect that calibration of a synthetic artificial recharge model, constrained by different combinations of measurements (pressure head, temperature, and concentration), has on estimated vadose zone model parameter-value nonuniqueness and predictive water, heat, and solute transport uncertainty. Several...
Effective discharge analysis of ecological processes in streams
Martin W. Doyle, Emily H. Stanley, David L. Strayer, Robert B. Jacobson, John C. Schmidt
2005, Water Resources Research (41)
Discharge is a master variable that controls many processes in stream ecosystems. However, there is uncertainty of which discharges are most important for driving particular ecological processes and thus how flow regime may influence entire stream ecosystems. Here the analytical method of effective discharge from fluvial geomorphology is used to...
Variations in climate and ephemeral channel recharge in southeastern Arizona, United States
D. R. Pool
2005, Water Resources Research (41)
Significant variations in interannual and decadal recharge rates are likely in alluvial basins of the semiarid southwestern United States on the basis of decadal variations in climate and precipitation and correlation of El Niño with high rates of winter precipitation and streamflow. A better understanding of the magnitude of recharge...
Assessing the potential for re-emission of mercury deposited in precipitation from arid soils using a stable isotope
J.A. Ericksen, M.S. Gustin, S.E. Lindberg, S.D. Olund, D. P. Krabbenhoft
2005, Environmental Science & Technology (39) 8001-8007
A solution containing 198Hg in the form of HgCl2 was added to a 4 m2 area of desert soils in Nevada, and soil Hg fluxes were measured using three dynamic flux chambers. There was an immediate release of 198Hg after it was applied, and then emissions decreased exponentially. Within the first...
Management scenarios for the Jordan River salinity crisis
E. Farber, A. Vengosh, I. Gavrieli, Amarisa Marie, T.D. Bullen, B. Mayer, R. Holtzman, M. Segal, U. Shavit
2005, Applied Geochemistry (20) 2138-2153
Recent geochemical and hydrological findings show that the water quality of the base flow of the Lower Jordan River, between the Sea of Galilee and the Dead Sea, is dependent upon the ratio between surface water flow and groundwater discharge. Using water quality data, mass-balance calculations, and actual flow-rate measurements,...
Changes toward earlier streamflow timing across western North America
I.T. Stewart, D.R. Cayan, M. D. Dettinger
2005, Journal of Climate (18) 1136-1155
The highly variable timing of streamflow in snowmelt-dominated basins across western North America is an important consequence, and indicator, of climate fluctuations. Changes in the timing of snowmelt-derived streamflow from 1948 to 2002 were investigated in a network of 302 western North America gauges by examining the center of mass...
Data collection and documentation of flooding downstream of a dam failure in Mississippi
K. Van Wilson Jr.
Moglen G.E., editor(s)
2005, Conference Paper, Proceedings of the 2005 Watershed Management Conference - Managing Watersheds for Human and Natural Impacts: Engineering, Ecological, and Economic Challenges
On March 12, 2004, the Big Bay Lake dam failed, releasing water and affecting lives and property downstream in southern Mississippi. The dam is located near Purvis, Mississippi, on Bay Creek, which flows into Lower Little Creek about 1.9 miles downstream from the dam. Lower Little Creek flows into Pearl...
Sources of variability of evapotranspiration in California
H.G. Hidalgo, D.R. Cayan, M. D. Dettinger
2005, Journal of Hydrometeorology (6) 3-19
The variability (1990–2002) of potential evapotranspiration estimates (ETo) and related meteorological variables from a set of stations from the California Irrigation Management System (CIMIS) is studied. Data from the National Climatic Data Center (NCDC) and from the Department of Energy from 1950 to 2001 were used to...
Use of individualistic streamflow-vegetation relations along the Fremont River, Utah, USA to assess impacts of flow alteration on wetland and riparian area
G.T. Auble, M. L. Scott, Jonathan M. Friedman
2005, Wetlands (25) 143-154
We analyzed the transverse pattern of vegetation along a reach of the Fremont River in Capitol Reef National Park, Utah, USA using models that support both delineation of wetland extent and projection of the changes in wetland area resulting from upstream hydrologic alteration. We linked stage-discharge relations developed by a...
