International Compendium Of Coastal Engineering

Shinji Sato, Masahiko Isobe

• Publisher: WSPC
• Year: 2015
• ISBN:
  9789814449441
• Topic: Biological Sciences
• Subtopic: Science General
• Index: Biological Sciences

The aim of this book is to provide a comprehensive overview of Coastal Engineering from basic theory to engineering practice. The authors of this book are worldwide authorities in the field. Each chapter deals with an important topic in the field of coastal engineering. The topics are of recent deep concern all over the world motivated by the 2004 Indian Ocean Tsunami, 2005 Hurricane Katrina, 2011 Tohoku Earthquake Tsunami and other natural disasters.For proper coastal zone management, a broad range of knowledge is necessary. This book provides a basic understanding of the theories behind the diverse natural phenomena within the coastal areas, such as waves, tsunamis and sediment transport. The book also introduces various coastal conservation technologies such as coastal structures and beach nourishment. Finally, coastal zone management practices in the USA, Europe, and Japan are introduced.Each chapter is self-standing and readers can begin from any topic depending on their interest.The aim of this book is to provide a comprehensive overview of Coastal Engineering from basic theory to engineering practice. The authors of this book are worldwide authorities in the field. Each chapter deals with an important topic in the field of coastal engineering. The topics are of recent deep concern all over the world motivated by the 2004 Indian Ocean Tsunami, 2005 Hurricane Katrina, 2011 Tohoku Earthquake Tsunami and other natural disasters.For proper coastal zone management, a broad range of knowledge is necessary. This book provides a basic understanding of the theories behind the diverse natural phenomena within the coastal areas, such as waves, tsunamis and sediment transport. The book also introduces various coastal conservation technologies such as coastal structures and beach nourishment. Finally, coastal zone management practices in the USA, Europe, and Japan are introduced.Each chapter is self-standing and readers can begin from any topic depending on their interest.Contents:Introduction (Robert L Wiegel)Random Waves in the Sea(Yoshimi Goda)Tsunamis — Their Coastal Effects and Defense Works (Nobuo Shuto)Basic Coastal Sediment Transport Mechanisms (Peter Nielsen)Morphology of Erosional and Accretionary Coasts (Paul D Komar and Tsuguo Sunamura)Numerical Modeling of Nearshore Wave Transformation(Hitoshi Nishimura and Masahiko Isobe)Physical Modeling — Renewed Importance (J William Kamphuis)Field Observations and Data Management (Gary P Mocke and Francois Smit)Beach Nourishment (Robert G Dean)Dredging of Navigational Channels (John B Herbich)Enhancement of Marine Habitats (Makoto Nakamura and Shinya Otake)Hydro-Environmental Assessment of Coastal and Estuarine Systems (H Lee Butler and Carl F Cerco)Coastal Zone Management (1) — US Perspective (Peter Grenell)Coastal Zone Management (2) — The European Perspective (Hans Kunz)Coastal Zone Management (3) — Sediment Movement and Beach Transformation Due to Port Construction in Japan (Kazumasa Katoh)Coastal Zone Management (4) — Downcoast Erosion Triggered by Exhaustion of Sand Supply from Sea Cliffs with Northern Kujukuri Beach in Japan Taken as Example (Takaaki Uda)View on Future Prospects of Coastal Engineering (Kiyoshi Horikawa)Key Features:This book focuses on important topics in coastal regionThis book covers topics from theories of waves and sand transport to coastal engineering practice such as beach protectionThis book provides advanced knowledge in coastal engineering

Chapter 1

Introduction

Robert L. Wiegel

Professor Emeritus,
University of California, USA

1.Introduction

In its broadest sense, coastal engineering started in antiquity. The name “coastal engineering”, however, was probably not used (at least in print) until 1950 — at the Institute on Coastal Engineering held in Long Beach, California, planned by Morrough P. O’Brien and J. W. Johnson, organized by the University of California Extension. The purpose of the program was to help engineers by summarizing the state-of-the-art and science, related to planning and designing coastal works; each of the 35 lectures was by invitation. The written versions were published as the Proceedings of First Conference on Coastal Engineering, edited by J. W. Johnson (1951). In the proceeding’s preface, O’Brien wrote:

“A word about the term “Coastal Engineering” is perhaps in order here. It is not a new or separate branch of engineering and there is no implication intended that a new breed of engineer, and a new society is in the making. Coastal Engineering is primarily a branch of Civil Engineering which leans heavily on the sciences of oceanography, meteorology, fluid mechanics, electronics, structural mechanics, and others (such as geology — RLW). However, it is also true that the design of coastal works does involve many criteria which are foreign to other phases of civil engineering and novices in this field should proceed with caution.”

Prior to, then there were coastal activities, works, studies and publications on aspects of coastal engineering: some in ancient times such as ports/harbors, lighthouses, fishing, salt water fishponds (piscina), evaporative salt ponds; and some mostly within the past century and a half, such as recreation. People have always lived along the coast owing in part to convenience in transportation (ocean and river) and relatively mild climate, its use as a source of food, and the ease in disposing of wastes (even though sometimes a health hazard). Its use has increased dramatically in the past century owing to population growth, the development of highway and rail systems, low-cost airlines, and great changes in the economic/social environment. Much had been learned in the past about operating in the coastal physical environment; about some characteristics of waves, winds, currents and tides; about the shoaling of harbors; about subsidence/uplift/earthquakes. But, it was not until World War II that major advances were made in analysis techniques and development and use of hydraulic laboratories — the combination of science and engineering — together with advances made in instruments and the increased measurement, analysis and data presentation of components of environmental processes (e.g. Wiegel and Saville, Jr., 1996). Most recent has been the use of digital computers in analysis, data handling and evaluation, and design.

The present book has two purposes: a celebration of coastal engineering for Professor Kiyoshi Horikawa, and looking towards the future beyond its golden anniversary. Professor Horikawa’s professional career has spanned nearly the entire half century of modern coastal engineering. He has been an important leader, teacher and researcher in the discipline; his large number of papers on diverse subjects, and his book (1978) are evidences of this. It is appropriate to have this celebration. I first worked with Professor Horikawa when he was a visiting assistant professor at the University of California at Berkeley, November 1957–April 1959 (Horikawa and Wiegel, 1959) and have met with him many times since then, often at the ICCEs. We have worked together, first at Berkeley, then on two US Japan Cooperative Science Program seminars: coastal engineering in 1964, and tsunamis in 1965. We wrote a paper about the first one for Civil Engineering (December 1964): “Coastal Engineering in Japan”. I value my 40 yrs of association with Professor Horikawa, and I am pleased to participate in honoring him.

The second purpose — the future of coastal engineering beyond its golden anniversary — is difficult. We have never been good in foreseeing the future, and when we have done so correctly, it has often been by luck. I will make a few predictions, but mostly will write what I think should be done in the future, as well as now. Certainly, the future will include more cooperative efforts to live better with the environment, to minimize harmful effects, and to plan and implement more regional rather than local projects. Multiple use of the coast is increasing, so more time and effort must be spent in finding solutions that will satisfy (perhaps only to some extent) a diversity of opinions by affected persons on what can (or should) be done, economically and socially. I think we will continue to recognize that although we have generalized theories, the combination (“mix”) of processes, forcings and boundary conditions makes nearly all projects different, each requiring a unique solution, and that the project performance should be monitored quantitatively. This has been recognized by others (e.g. O’Brien, 1972), but should be emphasized again. The more experience I gain, the more I believe it to be true. Also, the recent trend seems to be, at least in the USA, of making little use of hydraulic laboratory studies, and to rely mostly on numerical models and field investigations. I think this is a mistake which hopefully will be recognized and reversed, as all are needed. If a numerical model cannot predict correctly what is observed in a hydraulic model — and the “scale effects” — we should have no confidence in its use for prototype application. Both laboratory and field are part of the “real world”, and we learn from each.

Substantial advances have been made in our ability to analyze, design and construct coastal works, as is documented in the present book, and in History and Heritage of Coastal Engineering (Kraus, 1996). However, much remains to be done. Sometimes, we have to rectify or mitigate problems caused by the actions of others, such as chronic erosion or narrowing of beaches owing to a decrease in river transport of sand to the coast after the construction of dams, coastal subsidence resulting from withdrawal of oil/gas/water, construction of navigation works, or encroachment on beaches with buildings and infrastructure. Sometimes, engineers are even called upon to rectify a problem caused by a project which was built against their advice. In general, engineers are optimistic, learning from past works, and believing they can do a better job next time; perhaps this is one of the traits that leads us to become engineers — and when we find a societal need, we want to help society by developing a solution for it.

2.Origin and Needs of Coastal Engineering

A few anecdotes from the past, some ancient, some several centuries ago, and some recent, are both interesting and useful in illustrating the origin and needs of coastal engineering. We will recognize types of problems that are still with us, and why there is a continued demand for the resourcefulness of the human mind in coastal engineering — both research and practice. Also, they illustrate how much change can occur, physically and sociologically, and that we must expect and accommodate for these changes.

In antiquity, water-borne transport was often the most convenient manner of conveying cargo and people, and for heavy cargo, probably the only means. For some coastal works, there is only archaeological evidence, but for others, historical information is also available; as an example, ports/harbors have been used for more than 4,000 yrs in the Mediterranean Sea and elsewhere, and have been the subject of much archaeological and historical research. Many Roman ports/harbor sites have been investigated, but even earlier there were Egyptian, Phoenician and Greek coastal works.

Half-way through the time frame mentioned above, about 2,000 yrs ago, an artificial harbor, Caeseria Maritima (Sebastos Harbor), was built from shore into the open Mediterranean Sea by King Herod (Holum et al., 1988). Some archaeologists believe it to be at the site of Strato’s Tower, a Phoenician harbor used some two–four centuries prior to the construction of the new harbor. I mention this example, which has been studied extensively, because Roman engineering and construction techniques of great historical interest were used. This included “hydraulic concrete” (rubble stone and “cement” of lime and pozzuolana, a volcanic ash, which sets underwater, discovered in the 3rd Century BC) that was placed underwater in large size wooden form-works that had been weighted and set on the prepared bottom. Quarried limestone blocks were then laid above the large concrete units to form the breakwater. Use was likely made of wave overtopping/water storage/sluicing to dredge the harbor. The breakwaters deteriorated eventually, but their remnant can be seen through the water. They extend further seaward than the present harbor structures, which are modifications of the smaller Byzantine, Arabic, Crusader, and Turkish facilities which followed the Roman period. It appears that the breakwaters caused substantial changes in the transport and deposition of sand in the region, by waves moving it alongshore and by wind blowing great quantities of trapped sand inland. Some of the sand here, travelled from the Nile River, along the littoral of the southeastern Mediterranean Sea (Rohrlich and Goldsmith, 1984).

The ancient port of Ostia, which served Rome, was constructed in 43 AD just north of the mouth of the Tiber River. It was built against the advice of the engineers (Savile, 1940). It filled with sediment as the river delta built seaward, causing difficulties in the use of the harbor by the end of the 1st Century AD. It is no longer a harbor, and is about 2 miles inland (Bradford, 1957 as reported in Flemming, 1969). It is interesting that in the present century, particularly in the recent several decades, the beach at Lido di Ostia has eroded owing to the decrease in sand supplied to it by the Tiber River because of dams that had been built. This loss of sand has been mitigated by a beach nourishment and submerged shore-parallel breakwater perched beach project (Ferrante et al., 1992).

Earthquakes have always been with us. Almost the symbol of coastal engineering, is the famous Japanese painting of a tsunami generated by an undersea earthquake. Japan has had a long history of tsunamis, with disastrous ones in the past few years. The most recent, a terrible disaster that occurred on 11 March 2011, was the 2011 Tohoku earthquake (9.0 Mw) and tsunami in Sendai/Onagawa, Japan (e.g. Wikipedia, 2011). In 1996, in Hilo, Hawaii, a symposium was held to mark the 50th anniversary of the 1 April 1946 tsunami which was probably generated by a massive underwater slide triggered by the Aleutian Trench Earthquake. A few years after the tsunami, in 1948, the Seismic Sea Wave Warning System was established. It expanded, with a number of countries on the Pacific Rim participating, and the cooperative effort is now named the International Tsunami Warning System. Much scientific and coastal engineering research and development followed the event (e.g. Kaijura, 1963; Keller, 1963), and is still ongoing. We will learn more from Professor Shuto’s chapter in this book.

In another part of the world, the extensive archaeological/sea level changes study by Flemming (1969) of 179 coastal cities in the Western Mediterranean (with definite conclusions on 54 and relevant but inconclusive data on another 67), led him to state: “It is concluded that there has been no net eustatic change in the last 2000 years; that all submerged sites are due to earth movement; and that tectonic movements in the basin are predominantly downward.” In other regions of the earth, tectonic movements are upward, or sometimes upward in one part and downward in another part of the area during a single event, such as the 1964 Alaska Earthquake. For ancient events, we have more information on tectonic movement than for subsidence caused by liquefaction — an important problem today, especially where fill is used to create land for the large areas needed for cargo containers. We are all aware of the catastrophe at Kobe, Japan, caused by the 1995 Hyogo-ken Nanbu Earthquake.

There is little, if any, information on the effects of storm waves on ancient coastal structures. However, nearly 500 yrs ago (in the same decade that Columbus made his historic voyage across the Atlantic Ocean), waves of a great storm (in February, 1498) demolished the superstructure of the wall of the “Old Mole” in Genoa, Italy. The inspection and engineering report of the event was made by the artist/scientist/engineer of genius Leonardo da Vinci (D’Arrigo, 1955). Owing to the port’s location, the several breakwaters that have replaced the old one have been subject to many severe storms and damages (D’Arrigo, 1955). As a part of engineering studies, one of the first wave height gages made was in Genoa and installed on a section of the vertical concrete wall in water 15m deep, together with two vertical arrays of pressure cells (7 cells in each array) mounted in the wall to measure wave-induced forces.

Many natural, and some artificial, harbor entrances are difficult, or even dangerous to use. Just south of Biarritz, France is one described in the 16th Century “Sailing Directions of Pierre Garcie” (as translated by Waters, 1967): “Know that when the sea breaks more than two rollers on the Plateau de St. Jean de Luz (Bay of Biscay) you must not attempt to enter Le Boucaut; take heed indeed, because it is not worth it. But if the seas are not breaking you can go in safely.” Four centuries later, at the unimproved tidal entrance of Tomales Bay, CA (40 miles north of my University), about one small boat a year capsizes in large waves that break over the entrance bar — often when a strong ebb tidal current is flowing, and northwest winds blowing (Doyle, 1996). Improvement of entrances for safe navigation has been, and is, a major activity of coastal engineers. Sometimes, however, improvements cannot be made economically, and reliance must be placed on public education to improve safety.

The formation of a tidal estuary/lagoon inlet and its changes with time has been documented for Aveiro, Portugal since the 10th Century, with detailed information, including surveys, since the end of the 13th Century (Abecasis, 1955). It was formed by the evolution of a sand spit, and the harbor was used for shipping until the middle of the 18th Century. The entrance nearly closed in 1575, but it opened again. By the end of that century, and during the following century it was unstable, and navigation was difficult. It eventually closed by natural processes, becoming a barrier beach and lagoon, which occasionally opened. The lagoon became a swamp. The population of the city decreased to a small number. Many attempts were made to open and maintain an entrance. During the early part of the 19th Century, an artificial entrance was opened. Entrance works were built and sluicing used during the following years. Other substantial works were constructed in the 20th Century, with a major project in the 1930’s, and another in the 1950’s. There is probably more detailed long term information on this tidal estuary than any other.

Tidal entrances/estuaries/land reclamation/coastal wetlands are complex coupled nonlinear systems. In problems associated with these, as with many other problems, engineers are asked to serve as expert witnesses in courts of law. John Smeaton was the first to b...

Table of contents

• Cover Page
• Title Page
• Copyright
• Preface
• Contents
• 1. Introduction
• 2. Random Waves in the Sea
• 3. Tsunamis — Their Coastal Effects and Defense Works
• 4. Basic Coastal Sediment Transport Mechanisms
• 5. Morphology of Erosional and Accretionary Coasts
• 6. Numerical Modeling of Nearshore Wave Transformation
• 7. Physical Modeling — Renewed Importance
• 8. Field Observations and Data Management
• 9. Beach Nourishment
• 10. Dredging of Navigational Channels
• 11. Enhancement of Marine Habitats
• 12. Hydro-Environmental Assessment of Coastal and Estuarine Systems
• 13. Coastal Zone Management (1) — U.S. Perspective
• 14. Coastal Zone Management (2) — The European Perspective
• 15. Coastal Zone Management (3) Sediment Movement and Beach Transformation Due to Port Construction in Japan
• 16. Coastal Zone Management (4) — Downcoast Erosion Triggered by Exhaustion of Sand Supply from Sea Cliffs with Northern Kujukuri Beach in Japan Taken as Example
• 17. View on Future Prospects of Coastal Engineering