Uncertainty Reduction and Characterization of Complex Environmental Fate and Transport Models

Uncertainty Reduction and Characterization of Complex Environmental Fate and Transport Models PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

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Book Description
In this work, a computationally efficient Bayesian framework for the reduction and characterization of parametric uncertainty in computationally demanding environmental 3-D numerical models has been developed. The framework is based on the combined application of the Stochastic Response Surface Method (SRSM, which generates accurate and computationally efficient statistically equivalent reduced models) and the Markov Chain Monte Carlo method. The application selected to demonstrate this framework involves steady state groundwater flow at the U.S. Department of Energy Savannah River Site General Separations Area, modeled using the Subsurface Flow And Contaminant Transport (FACT) code. Input parameter uncertainty, based initially on expert opinion, was found to decrease in all variables of the posterior distribution. The joint posterior distribution obtained was then further used for the final uncertainty analysis of the stream baseflows and well location hydraulic head values.

Uncertainty Reduction and Characterization of Complex Environmental Fate and Transport Models

Uncertainty Reduction and Characterization of Complex Environmental Fate and Transport Models PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 5

Get Book Here

Book Description
In this work, a computationally efficient Bayesian framework for the reduction and characterization of parametric uncertainty in computationally demanding environmental 3-D numerical models has been developed. The framework is based on the combined application of the Stochastic Response Surface Method (SRSM, which generates accurate and computationally efficient statistically equivalent reduced models) and the Markov Chain Monte Carlo method. The application selected to demonstrate this framework involves steady state groundwater flow at the U.S. Department of Energy Savannah River Site General Separations Area, modeled using the Subsurface Flow And Contaminant Transport (FACT) code. Input parameter uncertainty, based initially on expert opinion, was found to decrease in all variables of the posterior distribution. The joint posterior distribution obtained was then further used for the final uncertainty analysis of the stream baseflows and well location hydraulic head values.

Environmental Fate and Transport Analysis with Compartment Modeling

Environmental Fate and Transport Analysis with Compartment Modeling PDF Author: Keith W. Little
Publisher: CRC Press
ISBN: 1439887969
Category : Science
Languages : en
Pages : 247

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Book Description
Environmental Fate and Transport Analysis with Compartment Modeling explains how to use the powerful, highly flexible, and intuitive compartment approach to estimate the distribution of chemical contaminants in environmental media in time and space. Add this Easy-to-Use Approach to Your Environmental Modeling Toolbox This numerical technique enables readers to easily develop the equations that describe complex environmental problems by assembling the equations out of compartmental building blocks. The compartments may describe spatial subunits of single- or multi-environmental media, and the way one hooks them together implicitly provides the dimensionality of the problem. With this approach, assembling the equations to describe chemical fate and transport in a three-dimensional, multimedia system is fundamentally no more challenging than a one-dimensional, single-medium problem. Go Beyond "Black Box" Modeling with the Flexible GEM Software The book includes access to the Generic Environmental Model (GEM), a new software package developed by the author. This software implements the compartment approach based on user-prepared input files and solves the resulting mathematical equations. It allows readers to solve linear, nonlinear, and steady-state problems and offers four methods for solving dynamic problems. Each solution technique is reviewed, along with the error properties and the criteria for avoiding or minimizing numerical errors. The book also describes solution techniques and the underlying mathematical theory for solving nonlinear systems. Compartment Modeling from the Ground Up, Made Accessible to Non-Mathematicians A user-friendly introduction to environmental compartment modeling for the beginning modeler, this is also a useful resource for the experienced modeler. It combines a reference on compartment modeling with a user’s guide to the GEM. Throughout, the GEM is used to illustrate the theory with numerous examples, while the theoretical discussions illuminate the GEM’s functionality.

Uncertainty Quantification

Uncertainty Quantification PDF Author: Ralph C. Smith
Publisher: SIAM
ISBN: 161197321X
Category : Computers
Languages : en
Pages : 400

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Book Description
The field of uncertainty quantification is evolving rapidly because of increasing emphasis on models that require quantified uncertainties for large-scale applications, novel algorithm development, and new computational architectures that facilitate implementation of these algorithms. Uncertainty Quantification: Theory, Implementation, and Applications provides readers with the basic concepts, theory, and algorithms necessary to quantify input and response uncertainties for simulation models arising in a broad range of disciplines. The book begins with a detailed discussion of applications where uncertainty quantification is critical for both scientific understanding and policy. It then covers concepts from probability and statistics, parameter selection techniques, frequentist and Bayesian model calibration, propagation of uncertainties, quantification of model discrepancy, surrogate model construction, and local and global sensitivity analysis. The author maintains a complementary web page where readers can find data used in the exercises and other supplementary material.

Integrated Environmental Modeling

Integrated Environmental Modeling PDF Author: Anu Ramaswami
Publisher: John Wiley & Sons
ISBN:
Category : Science
Languages : en
Pages : 696

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Book Description
A unified presentation of environmental model development, implementation, and testing Integrated Environmental Modeling teaches model development, model implementation, and model testing skills in a unified manner, crosscutting the three "media" comprising environmental systems--air, water, and soil--by focusing on parallels and similarities between them, and introducing a new generation of multimedia models. No other single volume offers comprehensive coverage of chemical transport and fate in all three environmental media, including the resulting impacts on the biosphere and human health, with a focus on the fundamental processes underlying environmental modeling. Integrated Environmental Modeling provides broad-based training in the development of pollutant transport and fate models in air, water, and soil, with a focus on five essential competencies: * Understanding the fundamental process principles that govern contaminant transport and transformations in multimedia environments, emphasizing the parallels and links between different media * Learning model development skills, starting from the simplest conceptual models and building more complex and realistic models that couple component process modules at the appropriate spatial and temporal scales of resolution * Using statistical methods and data sources to estimate input parameters and characterize model sensitivity and uncertainty * Gaining hands-on experience with computer-aided implementation and evaluation of fate and transport models using realistic case study examples * Applying fate and transport models to evaluate pollutant interactions with the biosphere, particularly in human exposure modeling and health risk assessment Complete with case studies, Integrated Environmental Modeling is a valuable, single-source tool for senior and graduate students in environmental science and engineering courses on pollutant transport, remediation, and risk assessment, and an essential reference text for professionals in industry, consulting, and government agencies responsible for environmental assessment and risk analysis.

Large-Scale Inverse Problems and Quantification of Uncertainty

Large-Scale Inverse Problems and Quantification of Uncertainty PDF Author: Lorenz Biegler
Publisher: John Wiley & Sons
ISBN: 1119957583
Category : Mathematics
Languages : en
Pages : 403

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Book Description
This book focuses on computational methods for large-scale statistical inverse problems and provides an introduction to statistical Bayesian and frequentist methodologies. Recent research advances for approximation methods are discussed, along with Kalman filtering methods and optimization-based approaches to solving inverse problems. The aim is to cross-fertilize the perspectives of researchers in the areas of data assimilation, statistics, large-scale optimization, applied and computational mathematics, high performance computing, and cutting-edge applications. The solution to large-scale inverse problems critically depends on methods to reduce computational cost. Recent research approaches tackle this challenge in a variety of different ways. Many of the computational frameworks highlighted in this book build upon state-of-the-art methods for simulation of the forward problem, such as, fast Partial Differential Equation (PDE) solvers, reduced-order models and emulators of the forward problem, stochastic spectral approximations, and ensemble-based approximations, as well as exploiting the machinery for large-scale deterministic optimization through adjoint and other sensitivity analysis methods. Key Features: Brings together the perspectives of researchers in areas of inverse problems and data assimilation. Assesses the current state-of-the-art and identify needs and opportunities for future research. Focuses on the computational methods used to analyze and simulate inverse problems. Written by leading experts of inverse problems and uncertainty quantification. Graduate students and researchers working in statistics, mathematics and engineering will benefit from this book.

Modelling of Pollutants in Complex Environmental Systems

Modelling of Pollutants in Complex Environmental Systems PDF Author: Grady Hanrahan
Publisher: ILM Publications
ISBN: 1906799016
Category : Nature
Languages : en
Pages : 489

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Book Description
Environmental modelling has enjoyed a long tradition, but there is a defined need to continually address both the power and the limitations of such models, as well as their quantitative assessment. This book showcases modern environmental modelling methods, the basic theory behind them and their incorporation into complex environmental investigations. It highlights advanced computing technologies and how they have led to unprecedented and adaptive modelling, simulation and decision-support tools to study complex environmental systems, and how they can be applied to current environmental concerns. This volume is essential reading for researchers in academia, industry and government-related bodies who have a vested interest in all aspects of environmental modelling. Features include: A range of modern environmental modelling techniques are described by experts from around the world, including the USA, Canada, Australia, Europe and Thailand; many examples from air, water, soil/sediment and biological matrices are covered in detail throughout the book; key chapters are included on modelling uncertainty and sensitivity analysis; and, a selection of figures are provided in full colour to enable greater comprehension of the topics discussed.

Quantifying Uncertainty in Subsurface Systems

Quantifying Uncertainty in Subsurface Systems PDF Author: Céline Scheidt
Publisher: John Wiley & Sons
ISBN: 1119325838
Category : Science
Languages : en
Pages : 306

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Book Description
Under the Earth's surface is a rich array of geological resources, many with potential use to humankind. However, extracting and harnessing them comes with enormous uncertainties, high costs, and considerable risks. The valuation of subsurface resources involves assessing discordant factors to produce a decision model that is functional and sustainable. This volume provides real-world examples relating to oilfields, geothermal systems, contaminated sites, and aquifer recharge. Volume highlights include: A multi-disciplinary treatment of uncertainty quantification Case studies with actual data that will appeal to methodology developers A Bayesian evidential learning framework that reduces computation and modeling time Quantifying Uncertainty in Subsurface Systems is a multidisciplinary volume that brings together five major fields: information science, decision science, geosciences, data science and computer science. It will appeal to both students and practitioners, and be a valuable resource for geoscientists, engineers and applied mathematicians. Read the Editors' Vox: eos.org/editors-vox/quantifying-uncertainty-about-earths-resources

Quantitative Modeling in Toxicology

Quantitative Modeling in Toxicology PDF Author: Kannan Krishnan
Publisher: John Wiley & Sons
ISBN: 0470686707
Category : Science
Languages : en
Pages : 504

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Book Description
Governments around the world are passing laws requiring industry to assess the toxicity of the chemicals and products they produce, but to do so while reducing, refining, or even replacing testing on animals. To meet these requirements, experimental toxicologists and risk assessors are adopting quantitative approaches and computer simulations to study the biological fate and effects of chemicals and drugs. In Quantitative Modeling in Toxicology leading experts outline the current state of knowledge on the modeling of dose, tissue interactions and tissue responses. Each chapter describes the mathematical foundation, parameter estimation, challenges and perspectives for development, along with the presentation of a modeling template. Additionally, tools and approaches for conducting uncertainty, sensitivity and variability analyses in these models are described. Topics covered include: the quantitative models of pharmacokinetics of individual chemicals and mixtures models for toxicant-target tissue interaction. models for cellular, organ, and organism responses. approaches, tools and challenges for model application and evaluation A website containing computer codes accompanies the book to help the reader reconstruct the models described and discussed in the various chapters. Quantitative Modeling in Toxicology serves as an essential reference source and tool box for risk assessors and researchers and students in toxicology, public health, pharmacology, and human toxicology interested in developing quantitative models for a better understanding of dose-response relationships.

Geography and Technology

Geography and Technology PDF Author: Stanley D. Brunn
Publisher: Springer Science & Business Media
ISBN: 9781402018718
Category : History
Languages : en
Pages : 656

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Book Description
This volume celebrates the 100th anniversary of the Association of American Geographers. It recognizes the importance of technologies in the production of geographical knowledge. The original chapters presented here examine technologies that have affected geography as a discipline. Among the technologies discussed are cartography, the camera, aerial photography, computers, and other computer-related tools. The contributors address the impact of such technologies on geography and society, disciplinary inquiries into the social/technological interfaces, high-tech as well low-tech societies, and applications of technologies to the public and private sectors. Geography and Technology can be used as a textbook in geography courses and seminars investigating specific technologies and the impacts of technologies on society and policy. It will also be useful for those in the humanities, social, policy and engineering sciences, planning and development fields where technology questions are becoming of increased importance. Geography clearly has much to learn from other disciplines and fields about geography/technology linkages; others can likewise learn much from us.

Calibration and Uncertainty Analysis for Complex Environmental Models

Calibration and Uncertainty Analysis for Complex Environmental Models PDF Author: John Doherty
Publisher:
ISBN: 9781320702478
Category : Environmental sciences
Languages : en
Pages : 237

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Book Description