Introduction to the Physics of Cohesive Sediment Dynamics in the Marine Environment


Book Description

This book is an introduction to the physical processes of cohesive sediment in the marine environment. It focuses on highly dynamic systems, such as estuaries and coastal seas. Processes on the continental shelf are also discussed and attention is given to the effects of chemistry, biology and gas.The process descriptions are based on hydrodynamic and soil mechanic principles, which integrate at the soil-water interface. This approach is substantiated through a classification scheme of sediment occurrences in which distinction is made between cohesive and granular material. Emphasis is also placed on the important interactions between turbulent flow and cohesive sediment suspensions, and on the impact of flow-induced forces on the stability of the seabed. An overview of literature on cohesive sediment dynamics is presented and a number of new developments are highlighted, in particular in relation to floc formation, settling and sedimentation, consolidation, bed failure and liquefaction and erosion of the bed. Moreover, it presents a summary on methods and techniques to measure the various sediment properties necessary to quantify the various parameters in the physical-mathematical model descriptions. A number of examples and case studies have been included.




Cohesive Sediments


Book Description

There is an alarming tendency today to assume that something calculated by a computer must be correct, yet the phrase 'garbage in, garbage out' (gigo) is possibly nowhere more (generally) appropriate than in computer modelling of cohesive sediment behaviour. The behaviour of 'mud' is highly complex and one only needs to look at a sample under a microscope to see why - the variety of particle shapes, not to mention the presence of living organisms, make it a substance with properties virtually unique to its situation which even change with time. For many years most researchers tended to avoid it, preferring to study sand and gravel, but a dedicated few tackled it and found a forum for discussing their work in the first Cohesive Sediments Workshop in Florida in 1980. The workshop met about every three years resulting in publication of some of the most definitive papers on the subject. By 1994 it was time to recognise the extensive research being carried on in Europe by holding the workshop in that region. Intercoh '94 (the 4th Nearshore and Estuarine Cohesive Sediment Transport Conference) drew together about 100 of the world's leading researchers in the field. The resulting papers, presented in this volume, truly represent the definitive state of the art on the measurement and modelling of mud properties today.




Fine Sediment Dynamics in the Marine Environment


Book Description

Cohesive sediment, or mud, is encountered in most water bodies throughout the world. Often mud is a valuable resource, synonymous with fertile land, enriching the natural environment and used as an important building material. Yet mud also hinders navigation and consequently, dredging operations have been carried out since ancient times to safeguard navigation. Unfortunately, many mud deposits are now contaminated, endangering the eco-system and increasing the costs of dredging operations. The transport and fate of mud in the environment are still poorly understood and the need for basic research remains. This text contains the proceedings of the INTERCOH-2000 conference on progress in cohesive sediment research. It was the sixth in a series of conferences initially started by Professor Ashish Mehta in 1984 as a "Workshop on Cohesive Sediment Dynamics with Special Reference to the Processes in Estuaries". During these conferences the character of the first workshop has always been maintained, that is, small scale and dedicated to the physical and engineering aspects of cohesive sediments, without parallel sessions, but with ample time for discussions during and after the presentations, and followed by a book of proceedings containing thoroughly reviewed papers. INTERCOH-2000 was integrated with the final workshop of the COSINUS project. This project was carried out as a part of the European MAST-3 programme, and almost all European cohesive sediment workers were involved. INTERCOH-2000 focused on the behaviour and modelling of concentrated benthic suspensions, i.e. high-concentrated near-bed suspensions of cohesive sediment. Special attention was paid to: sediment - turbulence interaction; flocculation and settling velocity; high-concentrated mud suspensions; processes in the bed - consolidation; processes on the bed - erosion; field observations on mud dynamics; instrumentation; and numerical modelling.




Estuarine Ecohydrology


Book Description

Estuarine Ecohydrology focuses on the principal components of an estuary. The book demonstrates how one can quantify an estuarine ecosystem's ability to cope with human stresses. The theories, models, and real-world solutions covered will serve as a toolkit for designing a management plan for the ecologically sustainable development of an estuary. This book is organized into seven chapters dealing with topics such as estuarine water circulation; estuarine sediment dynamics; tidal wetlands; estuarine food webs; and ecohydrology models and solutions. Although each chapter contains rigorous specialist knowledge, it is presented in an accessible way that encourages multi-disciplinary collaboration between such fields as hydrology, ecology and mathematical modeling. Estuarine Ecohydrology is appropriate for use as a textbook and as a reference for researchers; advanced undergraduate and graduate students in marine biology, oceanography, coastal management, and coastal engineering; coastal developers; resources managers, shipping operators; and those involved in estuarine fisheries and sustainable development communities. * Appropriate for use as a textbook and as a reference* Focuses on the principal components of an estuary* Presents theories, models, and real-world solutions to serve as a toolkit for designing a management plan for the ecologically sustainable development of an estuary




Estuarine Cohesive Sediment Dynamics


Book Description

The background for the Workshop on Cohesive Sediment Dynamics - . !!!!!. Special Reference to Physical Processes in Estuaries is briefly outlined in Chapter I. Here I wish to acknowledge those whose support I consider to be pivotal to this under taking. My deepest appreciation goes to Cynthia Vey, whose organizational skills and dedicated effort made the completion of this volume possible. Thanks are also due to Gail Terry for workshop organization, Jean Branson for word processing and Lillean Pieter for helping with drawings. Finally, I must express my sincere appreciation to Arthur Ezra 9f the National Science Foundation for providing support (through Grant No. CEE-8401185) for the workshop, and to Hsiang Wang for depart mental encouragement. With deepest regret, I must note the untimely death of Ranjan Ariathurai, 39, on June 5, 1985, before this volume could be published. He was a guiding force to many within the small group of researchers in cohesive sediment dynamics, and his professional brilliance and inspirational personal qualities constituted the true spirit . behind the workshop. I trust this volume will serve, albeit in a small way, as a fitting memory to this spirit, and to the remarkable professional contributions Ranjan made during his short career. Professor Ray B. Krone Professor Emmanuel Partheniades Department of Civil Engineering Department of Engineering Sciences University of California University of Florida Davis, California Gainesville, Florida TABLE OF CONTENTS CHAPTER PAGE I. INTRODUCTION Ashish J. Mehta •••••••••••••••••••••••••••••••••••••••••••••••••••• 1 II.




Modeling and Practice of Erosion and Sediment Transport under Change


Book Description

Climate and anthropogenic changes impact the conditions of erosion and sediment transport in rivers. Rainfall variability and, in many places, the increase of rainfall intensity have a direct impact on rainfall erosivity. Increasing changes in demography have led to the acceleration of land cover changes in natural areas, as well as in cultivated areas, and, sometimes, in degraded areas and desertified landscapes. These anthropogenized landscapes are more sensitive to erosion. On the other hand, the increase in the number of dams in watersheds traps a great portion of sediment fluxes, which do not reach the sea in the same amount, nor at the same quality, with consequences on coastal geomorphodynamics. This book is dedicated to studies on sediment fluxes from continental areas to coastal areas, as well as observation, modeling, and impact analysis at different scales from watershed slopes to the outputs of large river basins. This book is concentrated on a number of keywords: “erosion” and “sediment transport”, “model” and “practice”, and “change”. The keywords are briefly discussed with respect to the relevant literature. The contributions in this book address observations and models based on laboratory and field data, allowing researchers to make use of such resources in practice under changing conditions.




Estuarine and Coastal Fine Sediment Dynamics


Book Description

This volume is the product of the International Conference on Cohesive Sediment Transport (INTERCOH 2003) held at the Virginia Institute of Marine Science, U.S.A., during October 1-4, 2003. The topics included in this monograph range from basic research on cohesive sediment dynamics to practical applications. Also included with this book is a database that contains all experimental results as well as a comparison of numerical simulation results supported by the COSINUS project.* Provides fundamental knowledge of the dynamics of cohesive sediments* Presents practical applications of new finds on sedimentary processes* Includes valuable ready-for-use data




An Introduction To Hydraulics Of Fine Sediment Transport


Book Description

This book presents observations on the phenomena of fine sediment transport and their explanations under process-related divisions such as flocculation, erosion, and deposition.The text is a compilation of the author's lecture notes from nearly four decades of teaching and guiding graduate students in civil and coastal engineering. Illustrations of fine sediment transport processes and their complexities given in the book are taken from field and laboratory-based observations by the author and his students, as well as numerous investigators.The wide-ranging composition of particles (of inorganic and organic matter), their universal presence and their complex interactions with hydraulic forces make this branch of science a difficult one to deal with in a single treatise. It is therefore essential to study fine sediment transport as an independent subject rather than cover it in no more than a single chapter as many texts on coarse sediment transport have done.Even though the entire coverage is “introductory”, the twelve chapters collectively include more material than what can be reasonably dealt with in a one semester, three-credit course.The book includes an extensive description of the components of fine-grained — especially cohesive — sediment transport. It covers the development of the subject in scientific and engineering applications mainly from the 1950s to its present state. Solved examples and chapter-end exercises are also included.This text is aimed at senior civil engineering undergraduates and graduate students who, in the normal course of their study, seldom come across the subject of fine sediment transport in their curricula. Interested students should have a basic understanding of the mechanics of fluid flow and open channel hydraulics.




Encyclopedia of Coastal Science


Book Description

This new Encyclopedia of Coastal Science stands as the latest authoritative source in the field of coastal studies, making it the standard reference work for specialists and the interested lay person. Unique in its interdisciplinary approach. This Encyclopedia features contributions by 245 well-known international specialists in their respective fields and is abundantly illustrated with line-drawings and photographs. Not only does this volume offer an extensive number of entries, it also includes various appendices, an illustrated glossary of coastal morphology and extensive bibliographic listings.




Coasts and Estuaries


Book Description

Coasts and Estuaries: The Future provides valuable information on how we can protect and maintain natural ecological structures while also allowing estuaries to deliver services that produce societal goods and benefits. These issues are addressed through chapters detailing case studies from estuaries and coastal waters worldwide, presenting a full range of natural variability and human pressures. Following this, a series of chapters written by scientific leaders worldwide synthesizes the problems and offers solutions for specific issues graded within the framework of the socio-economic-environmental mosaic. These include fisheries, climate change, coastal megacities, evolving human-nature interactions, remediation measures, and integrated coastal management. The problems faced by half of the world living near coasts are truly a worldwide challenge as well as an opportunity for scientists to study commonalities and differences and provide solutions. This book is centered around the proposed DAPSI(W)R(M) framework, where drivers of basic human needs requires activities that each produce pressures. The pressures are mechanisms of state change on the natural system and Impacts on societal welfare (including well-being). These problems then require responses, which are the solutions relating to governance, socio-economic and cultural measures (Scharin et al 2016). - Covers estuaries and coastal seas worldwide, integrating their commonality, differences and solutions for sustainability - Includes global case studies from leading worldwide contributors, with accompanying boxes highlighting a synopsis about a particular estuary and coastal sea, making all information easy to find - Presents full color images to aid the reader in a better understanding of details of each case study - Provides a multi-disciplinary approach, linking biology, physics, climate and social sciences