Download or read book Evaluation of Uncertainty in Hydrodynamic Modeling written by and published by . This book was released on 2013 with total page 203 pages. Available in PDF, EPUB and Kindle. Book excerpt: Uncertainty analysis in hydrodynamic modeling is useful to identify and report the limitations of a model caused by different sources of error. In the practice, the main sources of errors are divided into model structure errors, errors in the input data due to measurement imprecision among other, and parametric errors resulting from the difficulty of identifying physically representative parameter values valid at the temporal and spatial scale of the models. This investigation identifies, implements, evaluates, and recommends a set of methods for the evaluation of model structure uncertainty, parametric uncertainty, and input data uncertainty in hydrodynamic modeling studies. A comprehensive review of uncertainty analysis methods is provided and a set of widely applied methods is selected and implemented in real case studies identifying the main limitations and benefits of their use in hydrodynamic studies. In particular, the following methods are investigated: the First Order Variance Analysis (FOVA) method, the Monte Carlo Uncertainty Analysis (MCUA) method, the Bayesian Monte Carlo (BMC) method, the Markov Chain Monte Carlo (MCMC) method and the Generalized Likelihood Uncertainty Estimation (GLUE) method. The results of this investigation indicate that the uncertainty estimates computed with FOVA are consistent with the results obtained by MCUA. In addition, the comparison of BMC, MCMC and GLUE indicates that BMC and MCMC provide similar estimations of the posterior parameter probability distributions, single-point parameter values, and uncertainty bounds mainly due to the use of the same likelihood function, and the low number of parameters involved in the inference process. However, the implementation of MCMC is substantially more complex than the implementation of BMC given that its sampling algorithm requires a careful definition of auxiliary proposal probability distributions along with their variances to obtain parameter samples that effectively belong to the posterior parameter distribution. The analysis also suggest that the results of GLUE are inconsistent with the results of BMC and MCMC. It is concluded that BMC is a powerful and parsimonious strategy for evaluation of all the sources of uncertainty in hydrodynamic modeling. Despites of the computational requirements of BMC, the method can be easily implemented in most practical applications.
Download or read book Evaluating Hydrodynamic Uncertainty in Oil Spill Modeling written by Xianlong Hou and published by . This book was released on 2013 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new method is presented to provide automatic sequencing of multiple hydrodynamic models and automated analysis of model forecast uncertainty. A Hydrodynamic and oil spill model Python (HyosPy) wrapper was developed to run the hydrodynamic model, link with the oil spill, and visualize results. The HyosPy wrapper completes the following steps automatically: (1) downloads wind and tide data (nowcast, forecast and historical); (2) converts data to hydrodynamic model input; (3) initializes a sequence of hydrodynamic models starting at pre-defined intervals on a multi-processor workstation. Each model starts from the latest observed data, so that the multiple models provide a range of forecast hydrodynamics with different initial and boundary conditions reflecting different forecast horizons. As a simple testbed for integration strategies and visualization on Google Earth, a Runge-Kutta 4th order (RK4) particle transport tracer routine is developed for oil spill transport. The model forecast uncertainty is estimated by the difference between forecasts in the sequenced model runs and quantified by using statistics measurements. The HyosPy integrated system with wind and tide force is demonstrated by introducing an imaginary oil spill in Corpus Christi Bay. The results show that challenges in operational oil spill modeling can be met by leveraging existing models and web-visualization methods to provide tools for emergency managers.
Download or read book Uncertainty Analysis of a Two dimensional Hydrodynamic Model written by Aaron Thompson and published by . This book was released on 2006 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Uncertainty Analysis of Hydrodynamic River Models written by Jord Warmink and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrodynamics and Transport for Water Quality Modeling written by James L. Martin and published by CRC Press. This book was released on 2018-05-04 with total page 820 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrodynamics and Transport for Water Quality Modeling presents a complete overview of current methods used to describe or predict transport in aquatic systems, with special emphasis on water quality modeling. The book features detailed descriptions of each method, supported by sample applications and case studies drawn from the authors' years of experience in the field. Each chapter examines a variety of modeling approaches, from simple to complex. This unique text/reference offers a wealth of information previously unavailable from a single source. The book begins with an overview of basic principles, and an introduction to the measurement and analysis of flow. The following section focuses on rivers and streams, including model complexity and data requirements, methods for estimating mixing, hydrologic routing methods, and unsteady flow modeling. The third section considers lakes and reservoirs, and discusses stratification and temperature modeling, mixing methods, reservoir routing and water balances, and dynamic modeling using one-, two-, and three-dimensional models. The book concludes with a section on estuaries, containing topics such as origins and classification, tides, mixing methods, tidally averaged estuary models, and dynamic modeling. Over 250 figures support the text. This is a valuable guide for students and practicing modelers who do not have extensive backgrounds in fluid dynamics.
Download or read book Uncertainty Modeling and Analysis in Engineering and the Sciences written by Bilal M. Ayyub and published by CRC Press. This book was released on 2006-05-25 with total page 401 pages. Available in PDF, EPUB and Kindle. Book excerpt: Engineers and scientists often need to solve complex problems with incomplete information resources, necessitating a proper treatment of uncertainty and a reliance on expert opinions. Uncertainty Modeling and Analysis in Engineering and the Sciences prepares current and future analysts and practitioners to understand the fundamentals of knowledge a
Download or read book Review of the St Johns River Water Supply Impact Study written by National Research Council and published by National Academies Press. This book was released on 2012-02-11 with total page 118 pages. Available in PDF, EPUB and Kindle. Book excerpt: The St. Johns River Water Management District is responsible for managing water resources in the St. Johns River basin, which comprises 23 percent of Florida. Approximately 4.73 million people (one-quarter of Florida's population) live in the area served by the District, which contains the growing cities of Jacksonville, Orlando, and Gainesville. In order to meet the increasing water supply needs of the District's residents and other water users, the District is considering supplementing its historical supply of groundwater with water from the St. Johns and Ocklawaha Rivers. To better understand the potential ecological impacts of such withdrawals, in 2008 the District began a large scientific study called the Water Supply Impact Study (WSIS). In late 2008, the Water Science and Technology Board (WSTB) of the National Academies was asked to review the progress of the WSIS, including such scientific aspects as hydrologic and water quality modeling and how river withdrawals will affect wetlands, biogeochemical processes, plankton, benthos, the littoral zone, fish, and wetlands wildlife in the basin. For two and a half years, the WSTB Committee has followed the activities of eight District workgroups as they modeled the relevant river basins, determined the criteria to evaluate the environmental impacts of water withdrawals, evaluated the extent of those impacts, and coordinated with other ongoing projects. The first report of the Committee reviewed the Phase 1 hydrologic and environmental assessment tools and relevant data, and made recommendations regarding proposed work for the second phase of the WSIS. The Committee's second report focused on how the District was responding to the recommendations in its first report. The third Committee report primarily evaluated the hydrologic and hydrodynamic work being performed by the District. Review of the St. Johns River Water Supply Impact Study, the fourth and final product of the Committee focuses on the ecological impact analyses conducted by the environmental workgroups, presents final thoughts about the hydrologic and hydrodynamic studies, and provides some overall perspectives on the WSIS.
Download or read book Numerical Modelling of Hydrodynamics for Water Resources written by Pilar Garcia Navarro and published by CRC Press. This book was released on 2007-11-01 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overland flow modelling has been an active field of research for some years, but developments in numerical methods and computational resources have recently accelerated progress, producing models for different geometries and types of flows, such as simulations of canal and river networks. Flow in canals has traditionally been described using one-dimensional, depth-averaged, shallow water models; but a variety of simulation techniques now facilitate the management of hydrodynamic systems, providing models which incorporate complex geometry and diverse flows. Much effort has gone into elaborating canal operational rules based on decision support systems, with the dual aim of assuring water delivery and meeting flow control constraints. In natural water courses, water management problems are associated with the need to meet quality standards. Numerical modelling of advection-diffusion can be used to manage problems related to the movement of solutes in rivers and aquifers. The analysis of solute transport is used to safeguard the quality of surface and ground water and to help prevent eutrophication. Solute flow through the soil can be dynamically linked to overland flow for hydrological and agricultural applications. Advances in modelling also cast new light on sediment transport in rivers, exploring the complex dynamics of river bed erosion and deposition and assist in thee analysis of river-reservoir systems. All these issues are discussed in Numerical Modelling of Hydrodynamics for Water Resources, which will be useful to civil engineers, applied mathematicians, hydrologists, and physicists.
Download or read book Aquananotechnology written by David E. Reisner and published by CRC Press. This book was released on 2014-09-24 with total page 1370 pages. Available in PDF, EPUB and Kindle. Book excerpt: The world’s fresh water supplies are dwindling rapidly—even wastewater is now considered an asset. By 2025, most of the world's population will be facing serious water stresses and shortages. Aquananotechnology: Global Prospects breaks new ground with its informative and innovative introduction of the application of nanotechnology to the remediation of contaminated water for drinking and industrial use. It provides a comprehensive overview, from a global perspective, of the latest research and developments in the use of nanotechnology for water purification and desalination methods. The book also covers approaches to remediation such as high surface area nanoscale media for adsorption of toxic species, UV treatment of pathogens, and regeneration of saturated media with applications in municipal water supplies, produced water from fracking, ballast water, and more. It also discusses membranes, desalination, sensing, engineered polymers, magnetic nanomaterials, electrospun nanofibers, photocatalysis, endocrine disruptors, and Al13 clusters. It explores physics-based phenomena such as subcritical water and cavitation-induced sonoluminescence, and fog harvesting. With contributions from experts in developed and developing countries, including those with severe contamination, such as China, India, and Pakistan, the book’s content spans a wide range of the subject areas that fall under the aquananotechnology banner, either squarely or tangentially. The book strongly emphasizes sorption media, with broad application to a myriad of contaminants—both geogenic and anthropogenic—keeping in mind that it is not enough for water to be potable, it must also be palatable.
Download or read book Uncertainty Analysis and Ocean Modeling Using the Shallow Water Equations written by Andrew William Coleman and published by . This book was released on 1999 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Modelling of Hydrodynamics for Water Resources written by Pilar Garcia Navarro and published by CRC Press. This book was released on 2007-09-17 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: Overland flow modelling has been an active field of research for some years, but developments in numerical methods and computational resources have recently accelerated progress, producing models for different geometries and types of flows, such as simulations of canal and river networks. Flow in canals has traditionally been described using
Download or read book Hydrodynamic Modeling and Ecological Risk based Design of Produced Water Discharge from an Offshore Platform written by and published by . This book was released on 2001 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Uncertainty Analysis in Modelling written by Uncertainty Analysis in Modelling and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Numerical Ship Hydrodynamics written by Lars Larsson and published by Springer Science & Business Media. This book was released on 2013-09-30 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book assesses the state-of-the-art in computational fluid dynamics (CFD) applied to ship hydrodynamics and provides guidelines for the future developments in the field based on the Gothenburg 2010 Workshop. It presents ship hull test cases, experimental data and submitted computational methods, conditions, grids and results. Analysis is made of errors for global (resistance, sinkage and trim and self-propulsion) and local flow (wave elevations and mean velocities and turbulence) variables, including standard deviations for global variables and propeller modeling for self-propulsion. The effects of grid size and turbulence models are evaluated for both global and local flow variables. Detailed analysis is made of turbulence modeling capabilities for capturing local flow physics. Errors are also analyzed for head-wave seakeeping and forward speed diffraction, and calm-water forward speed-roll decay. Resistance submissions are used to evaluate the error and uncertainty by means of a systematic verification and validation (V&V) study along with statistical investigations. Post-workshop experimental and computational studies are conducted and analyzed for evaluation of facility biases and to draw more concrete conclusions regarding the most reliable turbulence model, appropriate numerical methods and grid resolution requirements, respectively.
Download or read book Refining the Committee Approach and Uncertainty Prediction in Hydrological Modelling written by NAGENDRA. KAYASTHA and published by CRC Press. This book was released on 2018-09-27 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt: Due to the complexity of hydrological systems a single model may be unable to capture the full range of a catchment response and accurately predict the streamflows. A solution could be the in use of several specialized models organized in the so-called committees. Refining the committee approach is one of the important topics of this study, and it is demonstrated that it allows for increased predictive capability of models. Another topic addressed is the prediction of hydrologic models' uncertainty. The traditionally used Monte Carlo method is based on the past data and cannot be directly used for estimation of model uncertainty for the future model runs during its operation. In this thesis the so-called MLUE (Machine Learning for Uncertainty Estimation) approach is further explored and extended; in it the machine learning techniques (e.g. neural networks) are used to encapsulate the results of Monte Carlo experiments in a predictive model that is able to estimate uncertainty for the future states of the modelled system. Furthermore, it is demonstrated that a committee of several predictive uncertainty models allows for an increase in prediction accuracy. Catchments in Nepal, UK and USA are used as case studies. In flood modelling hydrological models are typically used in combination with hydraulic models forming a cascade, often supported by geospatial processing. For uncertainty analysis of flood inundation modelling of the Nzoia catchment (Kenya) SWAT hydrological and SOBEK hydrodynamic models are integrated, and the parametric uncertainty of the hydrological model is allowed to propagate through the model cascade using Monte Carlo simulations, leading to the generation of the probabilistic flood maps. Due to the high computational complexity of these experiments, the high performance (cluster) computing framework is designed and used. This study refined a number of hydroinformatics techniques, thus enhancing uncertainty-based hydrological and integrated modelling.
Download or read book Parameter Estimation and Uncertainty Quantification in Water Resources Modeling written by Philippe Renard and published by Frontiers Media SA. This book was released on 2020-04-22 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical models of flow and transport processes are heavily employed in the fields of surface, soil, and groundwater hydrology. They are used to interpret field observations, analyze complex and coupled processes, or to support decision making related to large societal issues such as the water-energy nexus or sustainable water management and food production. Parameter estimation and uncertainty quantification are two key features of modern science-based predictions. When applied to water resources, these tasks must cope with many degrees of freedom and large datasets. Both are challenging and require novel theoretical and computational approaches to handle complex models with large number of unknown parameters.
Download or read book Proceedings of the 15th International Ship and Offshore Structures Congress written by A.E Mansour and published by Elsevier. This book was released on 2003-06-26 with total page 523 pages. Available in PDF, EPUB and Kindle. Book excerpt: KEY FEATURES: Provides researchers in Ocean engineering with a thorough review of the latest research in the field Lengthy reports by leading experts A valuable resource for all interested in ocean engineering DESCRIPTION: The International Ship and Offshore Congress (ISSC) is a forum for the exchange of information by experts undertaking and applying marine structural research. These three volumes contain the eight technical committee reports, six Specialist Committee and 2 Special Task Committee reports which were presented for the 15th International Ship and Offshore Structures Congress (ISSC 2004) in San Diego USA, between 11th and 15th August 2003. Volume III will be published in 2004 and is to contain the discussion of the reports, the chairmen's reply, the text of the invited Lecture and the congress report of ISSC 2003.
