Download or read book Infragravity Velocity Profiles in the Surf zone written by Uday Putrevu and published by . This book was released on 1994 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Infragravity Waves in the Nearshore Zone written by Kent K. Hathaway and published by . This book was released on 1998 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the present state of knowledge on infragravity wave motions (nominally 0.003 to 0.05 Hz). Theoretical and observational studies are presented. Most of the studies discussed herein have been published elsewhere, however a few studies discussed in chapter 4 are presented for the first time in this report Measurements of nearshore waves and currents have shown that a significant amount of the total energy can be contained in the infragravity band, and on highly dissipative beaches the infragravity wave variance often dominates over energy in the incident wave band(0.05 to 0.3 Hz). An 8-month data set of infragravity variance measured at 8-m-depth at the shoreline (runup) was compared with incident wave variance. Analysis of the 8-m-depth data showed that high mode edge waves account for about 50 percent of the total infragravity variance, and as high as 80 percent at times. Significant edge wave heights greater than 20 cm were observed at the 8-m depth. Infragravity wave variance was shown to have a higher correlation with swell variance (C = 0.95) than with sea variance (C = 0.61). This report was motivated, in part, by the need to determine the significance of infragravity waves on coastal erosion and structure damage and by the desire to improve coastal engineering solutions to problems associated with nearshore processes.
Download or read book Surf zone Hydrodynamics written by Ib A. Svendsen and published by . This book was released on 1995 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Coastal and Ocean Engineering written by Philip L. F. Liu and published by World Scientific. This book was released on 1996 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains six papers discussing coastal processes, and physical and numerical modeling.In the first paper, Svendsen and Putrevu give an extensive review on the state of understanding of surf-zone hydrodynamics, including subjects such as wave breaking, wave-induced currents, and instability of nearshore currents and infragravity waves. They point out that the most urgent need is to develop an adequate theory for wave breaking and broken waves in the surf zone.One of the methods for studying the complex coastal processes is to perform laboratory experiments. However, physical models are always plagued by scale and laboratory effects, because the coastal process involves many different length and time scales. In the second paper, Kamphuis presents a detailed discussion on the sources and implications of the scale and laboratory effects on physical modeling.The third and the fourth papers are two parts of the discussion on the mathematical modeling of the meso-tidal barrier island coasts. To understand the dynamics of coastal inlet systems, one can either rely on empirical knowledge and construct various forms of empirical and semi-empirical models (Part I), or develop a set of mathematical models based on the physical processes (Part II). Although these models do not provide the details of the dynamics, they give valuable knowledge of the equilibrium-state relationships. de Vriend and Ribberink give a detailed review on two models, Initial Sedimentation/Erosion models and Medium-Term Morphodynamic models. They have also presented many examples of applications.In the fifth paper, Houston gives a brief review on different methods to mitigate beach loss caused by storms or persistent long-term erosion. He then describes, in detail, the method of beach nourishment, which is also called a beach fill. This paper discusses the information that must be collected to design a beach fill and that should be monitored after the completion of the project.The last paper of this volume shifts our attention to the design of offshore structures, such as gravity structures, floating barges and tankers. Chakrabarti discusses the effects of the uniform and shear currents on fixed and floating structures.
Download or read book The Measurement and Interpretation of Infragravity Shore Normal Surf Zone Water Surface Elevation Data written by R. C. Nelson and published by . This book was released on 1989 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances In Coastal And Ocean Engineering Vol 2 written by Philip L-f Liu and published by World Scientific. This book was released on 1996-07-03 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains six papers discussing coastal processes, and physical and numerical modeling.In the first paper, Svendsen and Putrevu give an extensive review on the state of understanding of surf-zone hydrodynamics, including subjects such as wave breaking, wave-induced currents, and instability of nearshore currents and infragravity waves. They point out that the most urgent need is to develop an adequate theory for wave breaking and broken waves in the surf zone.One of the methods for studying the complex coastal processes is to perform laboratory experiments. However, physical models are always plagued by scale and laboratory effects, because the coastal process involves many different length and time scales. In the second paper, Kamphuis presents a detailed discussion on the sources and implications of the scale and laboratory effects on physical modeling.The third and the fourth papers are two parts of the discussion on the mathematical modeling of the meso-tidal barrier island coasts. To understand the dynamics of coastal inlet systems, one can either rely on empirical knowledge and construct various forms of empirical and semi-empirical models (Part I), or develop a set of mathematical models based on the physical processes (Part II). Although these models do not provide the details of the dynamics, they give valuable knowledge of the equilibrium-state relationships. de Vriend and Ribberink give a detailed review on two models, Initial Sedimentation/Erosion models and Medium-Term Morphodynamic models. They have also presented many examples of applications.In the fifth paper, Houston gives a brief review on different methods to mitigate beach loss caused by storms or persistent long-term erosion. He then describes, in detail, the method of beach nourishment, which is also called a beach fill. This paper discusses the information that must be collected to design a beach fill and that should be monitored after the completion of the project.The last paper of this volume shifts our attention to the design of offshore structures, such as gravity structures, floating barges and tankers. Chakrabarti discusses the effects of the uniform and shear currents on fixed and floating structures.
Download or read book Time and Depth varying Cross shore Currents written by Jane M. Smith and published by . This book was released on 1996 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Shore Wave Modulation Due to Infragravity Waves in the Nearshore Zone with Applications written by Saad M. M. Abdelrahman and published by . This book was released on 1986 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: The omni-present low frequency wave motion (30-300 sec) contains a substantial fraction of the total wave energy inside the surf zone. A more complete description of nearshore wave processes considers incident short period waves superposed on, and interacting with, long standing waves. The wind waves are modulated in amplitude, wavenumber and direction due to relatively slowly varying depth changes caused by the long waves. The energy in the wind wave band is enhanced by side band growth at the sum and difference frequencies of short and long waves (order 15% at the shoreline). The modulation is identified in the analysis of field data as a positive correlation between the long waves and the wind wave envelope near the shoreline. Considering oblique incident waves, a steady longshore current showing a non-vanishing current at the shoreline is found as a result of the non-linear interaction between monochromatic incident and infragravity waves. An analytical solution describing the unsteadiness of the longshore current is developed. Keywords include: Infragravity, Longshore Current, Sediment transport, and Surf zone dynamics. (Theses).
Download or read book Infragravity Waves in the Nearshore Zone written by Kent K. Hathaway and published by . This book was released on 1998 with total page 100 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report summarizes the present state of knowledge on infragravity wave motions (nominally 0.003 to 0.05 Hz). Theoretical and observational studies are presented. Most of the studies discussed herein have been published elsewhere, however a few studies discussed in chapter 4 are presented for the first time in this report Measurements of nearshore waves and currents have shown that a significant amount of the total energy can be contained in the infragravity band, and on highly dissipative beaches the infragravity wave variance often dominates over energy in the incident wave band(0.05 to 0.3 Hz). An 8-month data set of infragravity variance measured at 8-m-depth at the shoreline (runup) was compared with incident wave variance. Analysis of the 8-m-depth data showed that high mode edge waves account for about 50 percent of the total infragravity variance, and as high as 80 percent at times. Significant edge wave heights greater than 20 cm were observed at the 8-m depth. Infragravity wave variance was shown to have a higher correlation with swell variance (C = 0.95) than with sea variance (C = 0.61). This report was motivated, in part, by the need to determine the significance of infragravity waves on coastal erosion and structure damage and by the desire to improve coastal engineering solutions to problems associated with nearshore processes.
Download or read book Coastal Dynamics written by and published by . This book was released on 1995 with total page 1092 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ocean System Studies The ocean system written by and published by . This book was released on 1989 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Observed Kinematics of Waves in the Surf Zone written by and published by . This book was released on 1999 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: The observed kinematics of waves in the surf zone is examined with extensive measurements from the DUCK94 experiment. Field data used in the study were obtained from vertical stacks of bi-directional current meters and a pressure sensor mounted on a rigid frame at 3 locations along a cross-shore transect in depths of 2,4, and 8m. Observed pressure and velocity spectra are compared to transfer functions based on linear finite depth theory and a simple nonlinear model that accounts for harmonic generation in shallow water. At high frequencies, the observed vertical aftenuation of horizontal velocity spectra in 8 and 4m depth is much weaker than predicted by linear theory and generally in good agreement with the nonlinear model predictions. In 2m depth, differences between the linear and nonlinear transfer function are small and both predictions are in reasonable agreement with the observed weak vertical decay. At infragravity frequencies in shallow water depths, observed velocity spectra often show significant vertical decay that is not predicted by either model. Velocity and pressure spectra measured in 4m depth are in good agreement with the nonlinear transfer function. Pressure spectra levels at high frequencies are shown to be significantly reduced by the nonlinear Bernoulli term in the second order pressure field. Analysis of the slopes of the high-frequency tails of the observed velocity spectra shows considerable scatter with a general tendency for spectra to flatten as waves rotate through the surf zone.
Download or read book Observed Kinematics of Waves in the Surf Zone written by Richard K. Constantian and published by . This book was released on 1999 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: The observed kinematics of waves in the surf zone is examined with extensive measurements from the DUCK94 experiment. Field data used in the study were obtained from vertical stacks of bi-directional current meters and a pressure sensor mounted on a rigid frame at 3 locations along a cross-shore transect in depths of 2,4, and 8m. Observed pressure and velocity spectra are compared to transfer functions based on linear finite depth theory and a simple nonlinear model that accounts for harmonic generation in shallow water. At high frequencies, the observed vertical aftenuation of horizontal velocity spectra in 8 and 4m depth is much weaker than predicted by linear theory and generally in good agreement with the nonlinear model predictions. In 2m depth, differences between the linear and nonlinear transfer function are small and both predictions are in reasonable agreement with the observed weak vertical decay. At infragravity frequencies in shallow water depths, observed velocity spectra often show significant vertical decay that is not predicted by either model. Velocity and pressure spectra measured in 4m depth are in good agreement with the nonlinear transfer function. Pressure spectra levels at high frequencies are shown to be significantly reduced by the nonlinear Bernoulli term in the second order pressure field. Analysis of the slopes of the high-frequency tails of the observed velocity spectra shows considerable scatter with a general tendency for spectra to flatten as waves rotate through the surf zone.
Download or read book Coastal Dynamics 95 written by William R. Dally and published by . This book was released on 1996 with total page 1084 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ninety-two proceedings papers from the 1995 conference reviewing large-scale field and laboratory experiments in the European Community, Japan, the US, and the former Soviet-Bloc countries of Russia, Bulgaria, East Germany, and Poland. These volume particularly features the discussions from those latter countries since most of their experiments have not been, until now, released to the West. In more specific terms, the papers report findings in wave motion in vegetated and non-vegetated coastal zone, surf zone modeling, planform considerations of beach nourishment, swash dynamics, runup, low- frequency motion, longshore currents, cross-shore transport, and profile evolution. Annotation copyright by Book News, Inc., Portland, OR
Download or read book Measuring Ocean Currents written by Antony Joseph and published by Newnes. This book was released on 2013-08-12 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measuring Ocean Currents: Tools, Technologies, and Data covers all major aspects of ocean current measurements in view of the implications of ocean currents on changing climate, increasing pollution levels, and offshore engineering activities. Although more than 70% of the Earth is covered by ocean, there is limited information on the countless fine- to large-scale water motions taking place within them. This book fills that information gap as the first work that summarizes the state-of-the-art methods and instruments used for surface, subsurface, and abyssal ocean current measurements. Readers of this book will find a wealth of information on Lagrangian measurements, horizontal mapping, imaging, Eulerian measurements, and vertical profiling techniques. In addition, the book describes modern technologies for remote measurement of ocean currents and their signatures, including HF Doppler radar systems, satellite-borne sensors, ocean acoustic tomography, and more. Crucial aspects of ocean currents are described in detail as well, including dispersion of effluents discharged into the sea and transport of beneficial materials—as well as environmentally hazardous materials—from one region to another. The book highlights several important practical applications, showing how measurements relate to climate change and pollution levels, how they affect coastal and offshore engineering activities, and how they can aid in tsunami detection. Coverage of measurement, mapping and profiling techniques Descriptions of technologies for remote measurement of ocean currents and their signatures Reviews crucial aspects of ocean currents, including special emphasis on the planet-spanning thermohaline circulation, known as the ocean's "conveyor belt," and its crucial role in climate change
Download or read book Coastal Storms written by Paolo Ciavola and published by John Wiley & Sons. This book was released on 2017-03-31 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive introduction to coastal storms and their associated impacts Coastal Storms offers students and professionals in the field a comprehensive overview and groundbreaking text that is specifically devoted to the analysis of coastal storms. Based on the most recent knowledge and contributions from leading researchers, the text examines coastal storms’ processes and characteristics, the main hazards (such as overwash, inundation and flooding, erosion, structures overtopping), and how to monitor and model storms. The authors include information on the most advanced innovations in forecasting, prediction, and early warning, which serves as a foundation for accurate risk evaluation and developing adequate coastal indicators and management options. In addition, structural overtopping and damage are explained, taking into account the involved hydrodynamic and morphodynamic processes. The monitoring methods of coastal storms are analyzed based on recent results from research projects in Europe and the United States. Methods for vulnerability and risk evaluation are detailed, storm impact indicators are suggested for different hazards and coastal management procedures analyzed. This important resource includes: Comprehensive coverage of storms and associated impacts, including meteorological coastal storm definitions and related potential consequences A state-of-the-art reference for advanced students, professionals and researchers in the field Chapters on monitoring methods of coastal storms, their prediction, early warning systems, and modeling of consequences Explorations of methods for vulnerability and risk evaluation and suggestions for storm impact indicators for different hazards and coastal management procedures Coastal Storms is a compilation of scientific and policy-related knowledge related to climate-related extreme events. The authors are internationally recognized experts and their work reflects the most recent science and policy advances in the field.
Download or read book Dynamics Of Coastal Systems written by Job Dronkers and published by World Scientific. This book was released on 2005-08-04 with total page 541 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dynamics of Coastal Systems is about the dynamic interaction between water motion and seabed topography, which affects the natural response of coastal systems to change in external conditions and to human interventions — from the scale of seabed ripples up to the scale of entire barrier and delta systems. The book highlights major concepts developed during the past 50 years for the description of current-topography, tide-topography and wave-topography interactions. It provides simple analytical tools and models for diagnosing and predicting coastal response to change, with references to a great variety of coastal systems around the world. These concepts and tools are crucial for sustainable management of beaches, deltas and coastal wetlands.The book is based on a master course on coastal morphodynamics given at the Universities of Utrecht and Delft in The Netherlands for graduate students who are familiar with the basic concepts of coastal hydrodynamics. It enables coastal engineers to complete their background knowledge and to facilitate access to cutting-edge scientific literature on specific topics. The book may also serve to familiarise consultants, practitioners and academics in related coastal disciplines with modern concepts of land-sea interaction.
