Lake resources at risk to acidic deposition in the eastern United States

Schnoor, Jerald L.; Lee, Sijin; Nikolaidis, Nikolaos P.; Nair, D. R.

doi:10.1007/bf00284254

Cited by 22 publications

(8 citation statements)

References 2 publications

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“…The low‐ANC seepage lakes in the study area typically have long hydraulic residence times and receive nearly all (>95%) of their hydrologic inflow from precipitation directly onto the lake surface. The hydraulic residence time, for example, was approximately five years in Vandercook Lake [13,15] and approximately 13 years in Crystal Lake [16]. Only two study lakes, Pallette and Russett, received measurable (<1% of the total hydrologic budget) groundwater input during the period from 1987 to 1990 [13,17].…”

Section: Methodsmentioning

confidence: 99%

Whole-lake burdens and spatial distribution of cadmium in sediments of Wisconsin seepage lakes, USA

Powell

Rada

Wiener

et al. 2000

Environmental Toxicology and Chemistry

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Abstract-Cadmium was quantified in the surface sediments of six seepage lakes ranging from 8 to 70 ha in surface area, 6 to 20 m in maximum depth, 5.2 to 7.0 in mean epilimnetic pH, and 1.7 to 6.8 mg·L Ϫ1 in dissolved organic carbon. Within each lake, dry-weight concentrations of cadmium (range, 0.02-7.17 g·g Ϫ1 ) were positively correlated with volatile matter content of the sediments, which increased with water depth. Volumetric concentrations (i.e., mass per volume of wet sediment) were correlated with water depth in only one lake, and they more accurately represented the spatial distribution of sedimentary cadmium within the lakes. Analysis of sediment cores from two of the lakes indicated that surface sediments were enriched with cadmium. The source of cadmium and the within-lake processes controlling deposition to the sediments were presumably similar among the lakes, as demonstrated by the strong correlation between lake area and whole-lake burdens of cadmium in the surface sediments (range, 625-5785 g/lake). Hence, cadmium in these lakes appears to be derived largely from atmospheric deposition. When normalized for lake area, cadmium burdens in the surface sediments ranged from 62 to 92 g·ha Ϫ1 and were strongly correlated with dissolved organic carbon, but not with lake pH, which suggests a link between the transport of cadmium and organic matter to the sediments.

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Section: Methodsmentioning

confidence: 99%

Whole-lake burdens and spatial distribution of cadmium in sediments of Wisconsin seepage lakes, USA

Powell

Rada

Wiener

et al. 2000

Environmental Toxicology and Chemistry

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“…Reuss, Christophersen, and Seip (1986) discussed the differences in scope and structure among these models which contain similar assumptions regarding several key soil chemical processes, in particular the anion mobility concept of Seip (1980), cation exchange, the carbonic-acid system, Al-bearing weathering and Al-hydroxide dissolution and precipitation (Reuss, Christophersen, and Seip 1986). The "Trickle Down" models of Schnoor and coworkers (Stumm, Morgan and Schnoor 1983;Schnoor and Stumm 1985;Schnoor, Nikolaidis, and Glass 1986;Lin and Schnoor, 1986) are based on mass balance for acid-neutralizing capacity (ANC). A variety of steady-state and dynamic models have been utilized ' within the NAPAP research efforts.…”

Section: Projections Of Future Changes In Surface Water Chemistry In mentioning

confidence: 99%

Comparison of MAGIC and Diatom paleolimnological model hindcasts of lakewater acidification in the Adirondack region of New York

Sullivan¹,

Bernert²,

Eliers³

et al. 1991

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PNL-7487 UC-603 encouragement and support, Robert Turner and Craig Brandt of Oak Ridge National Laboratory for assistance in data analysis, S. S. Dixit and B. F. Cumming of Queen's University for providing unpublished data; and E. C. Krug of the Illinois State Water Survey for his detailed critique of the report. This research would not have been possible without the considerable efforts of Robbins Church and coworkers in the Direct Delayed Response Project and of John Smol and coworkers in the PIRLA-11 project • iii Thirty-three lakes that had been statistically selected as part of the U.S. Environmental Protection Agency's Eastern Lake Survey and Direct Delayed Response Project (DDRP) were used to compare the MAGIC (watershed) and Diatom (paleolimnological) models. The study lakes represented a well-defined group of Adirondack lakes, each larger than 4 ha in area and having acidneutralizing capacity (ANC) < 400 ~eq L•'. The study first compared current and pre-industrial (before !850) pH and ANC estimates from Diatom and MAGIC as they were calibrated in the preceding Paleocological Investigation of Recent Lake Acidification (PIRLA) and DDRP studies, respectively. Initially, the comparison of hindcasts of pre-industrial chemistry was confounded by seasonal and methodological differences in lake chemistry data used in calibration of the models. Although certain differences proved to be of little significance for comparison, MAGIC did predict significantly higher pre-industrial ANC and pH values than did Diatom, using calibrations in the preceding studies. To remove known calibration biases, both models were recalibrated for selected scenarios. The more realistic pre-industrial sulfur deposition level (~13% of 1984 value) in the recalibrated MAGIC scenario reduced the hindcast ANC values significantly, reducing the discrepancy between the two models and indicating the sensitivity of process-level watershed models to assumptions concerning the quantity of atmospheric deposition. The reaggregation to subregional soils data appeared to produce little effect on hindcast ANC and pH values. A recalibrated MAGIC scenario using reaggregated soils data, sulfate loss-tolake sediment, and partial pressure of C0 2 specific to the Adirondack subregion, was also compared to a Diatom scenario using a similar sum of base cations minus sum of strong acid anions definition of ANC. The result yielded MAGIC hindcasts closer to Diatom hindcasts, but still significantly higher pre-industrial ANC and pH values than suggested by the Diatom model. Both models suggest acidification of low ANC Adirondack region lakes since preindustrial times, but differ primarily in that MAGIC inferred greater acidification and that acidification has occurred in all lakes in the comparison, whereas Diatom inferred that acidification has been restricted to low ANC lakes (

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“…The empirical cumulative distribution function exhibits a heavy upper tail, and the sample histogram for log(ANC (Schnoor, Lee, Nikolaidis, and Nair 1985;Schnoor, Nikolaidis, and Glass 1986) indicate that many relevant covariates are categorical with two or more categories. For example, hydrologic drainage pattern appears to play an important role.…”

Section: (8)mentioning

confidence: 99%

An Application of the Laplace Method to Finite Mixture Distributions

Crawford

1994

Journal of the American Statistical Association

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An exact Bayesian analysis of finite mixture distributions is often computationally infeasible, because the number of terms in the posterior density grows exponentially with the sample size. A modification of the Laplace method is presented and applied to estimation of posterior functions in a Bayesian analysis of finite mixture distributions. The procedure, which involves computations similar to those required in maximum likelihood estimation, is shown to have high asymptotic accuracy for finite mixtures of certain exponential-family densities. For these mixture densities, the posterior density is also shown to be asymptotically normal. An approximation of the posterior density of the number of components is presented. The method is applied to Duncan's barley data and to a distribution of lake chemistry data for north-central Wisconsin.

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Lake resources at risk to acidic deposition in the eastern United States

Cited by 22 publications

References 2 publications

Whole-lake burdens and spatial distribution of cadmium in sediments of Wisconsin seepage lakes, USA

Whole-lake burdens and spatial distribution of cadmium in sediments of Wisconsin seepage lakes, USA

Comparison of MAGIC and Diatom paleolimnological model hindcasts of lakewater acidification in the Adirondack region of New York

An Application of the Laplace Method to Finite Mixture Distributions

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