Coupled Flow And Contaminant Transport Modeling In Large Watersheds PDF Download

Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Coupled Flow And Contaminant Transport Modeling In Large Watersheds PDF full book. Access full book title Coupled Flow And Contaminant Transport Modeling In Large Watersheds.

Coupled Flow and Contaminant Transport Modeling in Large Watersheds

Coupled Flow and Contaminant Transport Modeling in Large Watersheds
Author: Orhan Gunduz
Publisher:
Total Pages: 934
Release: 2004
Genre: Hydrologic models
ISBN:
GET BOOK

Download Coupled Flow and Contaminant Transport Modeling in Large Watersheds Book in PDF, ePub and Kindle

A hybrid surface/subsurface flow and transport model is developed that blends distributed parameter models with simpler lumped parameter models. The hybrid model solves the channel flow and saturated groundwater flow domains in continuous time using fully distributed physically-based formulations. This system is supplemented with the overland flow and unsaturated groundwater flow that uses lumped parameter descriptions in discrete time. In the proposed model, a one-dimensional channel flow model is dynamically coupled with a two-dimensional vertically-averaged groundwater flow model along the river bed. As an alternative to the commonly applied iterative solution technique, a so-called simultaneous solution procedure is developed to provide a better understanding to the coupled flow problem. This new methodology is based on the principle of solving the two flow domains within a single matrix structure in a simultaneous manner. In addition to the flow model, a coupled contaminant transport model is also developed to simulate the migration of contaminants between surface and subsurface domains. The contaminant transport model dynamically couples a one-dimensional channel transport model with a two-dimensional vertically-averaged groundwater transport model. The coupling is performed at the river bed interface via advective and dispersive transport mechanisms. A modified extension of the proposed simultaneous solution procedure is also implemented to solve the coupled contaminant transport problem. The dynamic coupling provides the much needed understanding for the continuity of contaminants in strongly interacting surface/subsurface systems such as a river and an unconfined aquifer. The coupled flow and transport models are applied to the lower Altamaha watershed in southern Georgia. The flow model is used to perform simulations of hydrologic and hydraulic conditions along the river and in the dynamically linked surfacial aquifer. The model predicted the flood patterns including the magnitude of peaks and their arrival times with accuracy. Under the given flow conditions, the transport model is then implemented to test alternative contaminant transport patterns both in the river and within the aquifer. It has been found that the channel network would serve as a conduit for rapid transport of contaminants within the aquifer to large distances in small time frames.

Modeling Groundwater Flow and Contaminant Transport

Modeling Groundwater Flow and Contaminant Transport
Author: Jacob Bear
Publisher: Springer Science & Business Media
Total Pages: 851
Release: 2010-01-18
Genre: Science
ISBN: 1402066821
GET BOOK

Download Modeling Groundwater Flow and Contaminant Transport Book in PDF, ePub and Kindle

In many parts of the world, groundwater resources are under increasing threat from growing demands, wasteful use, and contamination. To face the challenge, good planning and management practices are needed. A key to the management of groundwater is the ability to model the movement of fluids and contaminants in the subsurface. The purpose of this book is to construct conceptual and mathematical models that can provide the information required for making decisions associated with the management of groundwater resources, and the remediation of contaminated aquifers. The basic approach of this book is to accurately describe the underlying physics of groundwater flow and solute transport in heterogeneous porous media, starting at the microscopic level, and to rigorously derive their mathematical representation at the macroscopic levels. The well-posed, macroscopic mathematical models are formulated for saturated, single phase flow, as well as for unsaturated and multiphase flow, and for the transport of single and multiple chemical species. Numerical models are presented and computer codes are reviewed, as tools for solving the models. The problem of seawater intrusion into coastal aquifers is examined and modeled. The issues of uncertainty in model input data and output are addressed. The book concludes with a chapter on the management of groundwater resources. Although one of the main objectives of this book is to construct mathematical models, the amount of mathematics required is kept minimal.

Numerical Modeling of Coupled Groundwater and Surface Water Interactions in an Urban Setting

Numerical Modeling of Coupled Groundwater and Surface Water Interactions in an Urban Setting
Author:
Publisher:
Total Pages: 37
Release: 2007
Genre:
ISBN:
GET BOOK

Download Numerical Modeling of Coupled Groundwater and Surface Water Interactions in an Urban Setting Book in PDF, ePub and Kindle

The Dominguez Channel Watershed (DCW), located in the southern portion of Los Angeles County (Figure A.1), drains about 345 square miles into the Los Angeles Harbor. The cities and jurisdictions in DCW are shown in Figure A.2. The largest of these include the cities of Los Angeles, Carson, and Torrance. This watershed is unique in that 93% of its land area is highly developed (i.e. urbanized). The watershed boundaries are defined by a complex network of storm drains and flood control channels, rather than being defined by natural topography. Table (1) shows a summary of different land uses in the Dominguez Channel Watershed (MEC, 2004). The Dominguez Watershed has the highest impervious area of all watersheds in the Los Angeles region. The more impervious the surface, the more runoff is generated during a storm. Storm water runoff can carry previously accumulated contaminants and transport them into receiving water systems. Point sources such as industrial wastewater and municipal sewage as well as urban runoff from commercial, residential, and industrial areas are all recognized as contributors to water quality degradation at DWC. Section 303(d) of the 1972 Federal Clean Water Act (CWA) requires states to identify and report all waters not meeting water quality standards and to develop action plans to pursue the water quality objectives. These plans specify the maximum amount of a given pollutant that the water body of concern can receive and still meet water quality standards. Such plans are called Total Maximum Daily Loads (TMDLs). TMDLs also specify allocations of pollutant loadings to point and non-point sources taking into account natural background pollutant levels. This demonstrates the importance of utilizing scientific tools, such as flow and transport models, to identify contaminant sources, understand integrated flow paths, and assess the effectiveness of water quality management strategies. Since overland flow is a very important component of the water balance and hydrology of DCW, a parallel, distributed watershed model that treats flow in groundwater and surface water in a dynamically coupled manner will be used to build a flow model of the watershed. This coupled model forms the basis for modeling and understanding the transport of contaminants through the Dominguez Channel Watershed, which can be used in designing and implementing TMDLs to manage the water quality in this basin. In this report, the coupled surface water-groundwater flow model of DCW will be presented. This flow model was calibrated against a storm that occurred in February 21st, 2004. The model and approach are explained further in the following sections.

Watershed Models

Watershed Models
Author: Vijay P. Singh
Publisher: CRC Press
Total Pages: 678
Release: 2010-09-28
Genre: Science
ISBN: 1420037439
GET BOOK

Download Watershed Models Book in PDF, ePub and Kindle

Watershed modeling is at the heart of modern hydrology, supplying rich information that is vital to addressing resource planning, environmental, and social problems. Even in light of this important role, many books relegate the subject to a single chapter while books devoted to modeling focus only on a specific area of application. Recognizing the

Groundwater and Ecosystems

Groundwater and Ecosystems
Author: Alper Baba
Publisher: Springer Science & Business Media
Total Pages: 319
Release: 2006-07-15
Genre: Science
ISBN: 140204738X
GET BOOK

Download Groundwater and Ecosystems Book in PDF, ePub and Kindle

Many problems related to groundwater and ecosystems are shared by countries throughout the world and there is growing recognition that much can be gained by co-operation on an international scale. This is no time for complacency and it is critical that key problems be identified, that the potential consequences of these problems be understood, and that the development of solutions begins urgently. Important data gaps must be recognized and filled without delay.

Numerical Simulation of Flow, Sediment, and Contaminant Transport in Integrated Surface-subsurface Systems

Numerical Simulation of Flow, Sediment, and Contaminant Transport in Integrated Surface-subsurface Systems
Author: Zhiguo He
Publisher:
Total Pages: 392
Release: 2007
Genre:
ISBN:
GET BOOK

Download Numerical Simulation of Flow, Sediment, and Contaminant Transport in Integrated Surface-subsurface Systems Book in PDF, ePub and Kindle

Hydro-system within a watershed includes many environmental processes, such as rainfall, runoff, groundwater flow, infiltration, evapotranspiration, recharge, upland erosion, sediment transport, and contaminant transport. In order to investigate these processes and evaluate their effects on water environments, numerical models have been recognized as an increasingly efficient and effective tool. Due to the natural intrinsic connections between surface and subsurface waters, modeling of flow, upland soil erosion, and contaminant transport should be considered as an integrated system. This dissertation has developed a physically-based integrated numerical model for flow, sediment, and contaminant transport in the surface-subsurface system. In this model, the surface flow is calculated using a depth-averaged 2-D diffusion wave model, and the variably saturated subsurface flow is computed using the 3-D mixed-form Richards equation. Interactions between surface and subsurface flows are considered using the continuity conditions of the pressure head and exchange flux at the ground surface. A general form of the surface flow equation based on the diffusion wave approximation is developed, which is intrinsically coupled with the variably saturated subsurface flow equation. The upland soil erosion and transport model employs the concept of nonequilibrium that considers both erosion and deposition. The model simulates nonuniform total-load sediment transport, with detachments from rainsplash and/or hydraulic erosion driven by overland flow. Contaminant transports in both surface and subsurface domains are described using advection-diffusion equations. The model considers the sediment sorption and desorption of the contaminant, as well as contaminant exchanges between surface and subsurface due to infiltration, diffusion, and bed change. The integrated numerical model is evaluated by simulating several published laboratory- and field-scale experiments. It is further applied to compute flow discharge, sediment and pesticide concentration during storm events in the Deep Hollow Lake watershed, Mississippi. The sensitivity analysis of the model is also performed using different values for several model parameters. The results have shown that the integrated model framework is capable of simulating the rainfall-runoff related hydrological processes in natural surface-subsurface systems.

An Integrated Hydrology/hydraulic and Water Quality Model for Watershed-scale Simulations

An Integrated Hydrology/hydraulic and Water Quality Model for Watershed-scale Simulations
Author: Cheng Wang
Publisher:
Total Pages: 188
Release: 2009
Genre: Hydraulics
ISBN:
GET BOOK

Download An Integrated Hydrology/hydraulic and Water Quality Model for Watershed-scale Simulations Book in PDF, ePub and Kindle

This dissertation presents the design of an integrated watershed model, WASH123D version 3.0, a first principle, physics-based watershed-scale model of integrated hydrology/hydraulics and water quality transport. This numerical model is comprised of three modules: (1) a one-dimensional (1-D) simulation module that is capable of simulating separated and coupled fluid flow, sediment transport and reaction-based water quality transport in river/stream/canal networks and through control structures; (2) a two-dimensional (2-D) simulation module, capable of simulating separated and coupled fluid flow, sediment transport, and reactive biogeochemical transport and transformation in two-dimensional overland flow systems; and (3) a three-dimensional (3-D) simulation module, capable of simulating separated and coupled fluid flow and reactive geochemical transport and transformation in three-dimensional variably saturated subsurface systems. The Saint Venant equation and its simplified versions, diffusion wave and kinematic wave forms, are employed for surface fluid flow simulations and the modified Richards equation is applied for subsurface flow simulation. The reaction-based advection-dispersion equation is used as the governing equation for water quality transport. Several physically and mathematically based numerical options are provided to solve these governing equations for different application purposes. The surface-subsurface water interactions are considered in the flow module and simulated on the basis of continuity of interface. In the transport simulations, fast/equilibrium reactions are decoupled from slow/kinetic reactions by the decomposition of reaction networks; this enables robust numerical integrations of the governing equation. Kinetic variables are adopted as primary dependent variables rather than biogeochemical species to reduce the number of transport equations and simplify the reaction terms. In each time step, hydrologic/hydraulic variables are solved in the flow module; kinetic variables are then solved in the transport module. This is followed by solving the reactive chemical system node by node to yield concentrations of all species. Application examples are presented to demonstrate the design capability of the model. This model may be of interest to environmental scientists, engineers and decision makers as a comprehensive assessment tool to reliably predict the fluid flow as well as sediment and contaminant transport on watershed scales so as to evaluate the efficacy and impact of alternative watershed management and remediation techniques prior to incurring expense in the field.

Handbook of Applied Hydrology, Second Edition

Handbook of Applied Hydrology, Second Edition
Author: Vijay P. Singh
Publisher: McGraw Hill Professional
Total Pages: 1438
Release: 2016-03-07
Genre: Technology & Engineering
ISBN: 0071835105
GET BOOK

Download Handbook of Applied Hydrology, Second Edition Book in PDF, ePub and Kindle

Fully Updated Hydrology Principles, Methods, and Applications Thoroughly revised for the first time in 50 years, this industry-standard resource features chapter contributions from a “who’s who” of international hydrology experts. Compiled by a colleague of the late Dr. Chow, Chow’s Handbook of Applied Hydrology, Second Edition, covers scientific and engineering fundamentals and presents all-new methods, processes, and technologies. Complete details are provided for the full range of ecosystems and models. Advanced chapters look to the future of hydrology, including climate change impacts, extraterrestrial water, social hydrology, and water security. Chow’s Handbook of Applied Hydrology, Second Edition, covers: · The Fundamentals of Hydrology · Data Collection and Processing · Hydrology Methods · Hydrologic Processes and Modeling · Sediment and Pollutant Transport · Hydrometeorologic and Hydrologic Extremes · Systems Hydrology · Hydrology of Large River and Lake Basins · Applications and Design · The Future of Hydrology

Plans and Practices for Groundwater Protection at the Los Alamos National Laboratory

Plans and Practices for Groundwater Protection at the Los Alamos National Laboratory
Author: National Research Council
Publisher: National Academies Press
Total Pages: 104
Release: 2007-10-18
Genre: Nature
ISBN: 0309106192
GET BOOK

Download Plans and Practices for Groundwater Protection at the Los Alamos National Laboratory Book in PDF, ePub and Kindle

The world's first nuclear bomb was a developed in 1954 at a site near the town of Los Alamos, New Mexico. Designated as the Los Alamos National Laboratory (LANL) in 1981, the 40-square-mile site is today operated by Log Alamos National Security LLC under contract to the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy (DOE). Like other sites in the nation's nuclear weapons complex, the LANL site harbors a legacy of radioactive waste and environmental contamination. Radioactive materials and chemical contaminants have been detected in some portions of the groundwater beneath the site. Under authority of the U.S. Environmental Protection Agency, the State of New Mexico regulates protection of its water resources through the New Mexico Environment Department (NMED). In 1995 NMED found LANL's groundwater monitoring program to be inadequate. Consequently LANL conducted a detailed workplan to characterize the site's hydrogeology in order to develop an effective monitoring program. The study described in Plans and Practices for Groundwater Protection at the Los Alamos National Laboratory: Final Report was initially requested by NNSA, which turned to the National Academies for technical advice and recommendations regarding several aspects of LANL's groundwater protection program. The DOE Office of Environmental Management funded the study. The study came approximately at the juncture between completion of LANL's hydrogeologic workplan and initial development of a sitewide monitoring plan.