Mercury in Fish, Bed Sediment, and Water from Streams Across the United States, 1998-2005
Mercury in Fish, Bed Sediment, and Water from Streams Across the United States, 1998-2005

Author: Barbara C. Scudder

Publisher: DIANE Publishing

Published: 2010-08

Total Pages: 86

ISBN-13: 1437921132

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Report on how mercury (Hg) was examined in top-predator fish, bed sediment, and water from streams that spanned regional and national gradients of Hg source strength and other factors thought to influence methylmercury bioaccum. Sampled settings include stream basins that were agr¿l, urbanized, undeveloped, and mined. Predator fish were targeted for collection, and composited samples of fish were analyzed for total Hg (THg), as most of the Hg found in fish tissue is MeHg. Samples of bed sediment and stream water were analyzed for THg, MeHg, and characteristics thought to affect Hg methylation, such as loss-on-ignition and acid-volatile sulfide in bed sediment, and pH, dissolved organic carbon, and dissolved sulfate in water. Illus.

Applied Groundwater Modeling
Applied Groundwater Modeling

Author: Mary P. Anderson

Publisher: Academic Press

Published: 2015-08-13

Total Pages: 632

ISBN-13: 0080916384

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This second edition is extensively revised throughout with expanded discussion of modeling fundamentals and coverage of advances in model calibration and uncertainty analysis that are revolutionizing the science of groundwater modeling. The text is intended for undergraduate and graduate level courses in applied groundwater modeling and as a comprehensive reference for environmental consultants and scientists/engineers in industry and governmental agencies. - Explains how to formulate a conceptual model of a groundwater system and translate it into a numerical model - Demonstrates how modeling concepts, including boundary conditions, are implemented in two groundwater flow codes-- MODFLOW (for finite differences) and FEFLOW (for finite elements) - Discusses particle tracking methods and codes for flowpath analysis and advective transport of contaminants - Summarizes parameter estimation and uncertainty analysis approaches using the code PEST to illustrate how concepts are implemented - Discusses modeling ethics and preparation of the modeling report - Includes Boxes that amplify and supplement topics covered in the text - Each chapter presents lists of common modeling errors and problem sets that illustrate concepts