Coastal and estuarine sediment dynamics by K.R. Dyer. Wiley, Chichester, 1986. No. of pages: 358. Price: ±36.00 (Hardback)

Abstract

It is a brave man who sets out to bring together the accumulated wisdom of a number of separate and well-defined disciplines to produce a coherent text-book, particularly when the subject area is still undergoing active research and development. This book distills elements of geology, oceanography, and engineering into a broad review of sediments and their movement in tidal waters. A specialist in any one of these disciplines might reasonably argue that the book gives the subject a superficial treatment: in this sense it is not a text- book. But given the magnitude of the task, the author has achieved a great deal, particularly in providing an excellent frame of reference that will help the reader to explore relevant knowledge beyond the usual disciplinary boundaries. This is a subject in which little is precisely analysed and neatly bound by theory. Much depends on empirical measurement and experimentation, and it is a strength of this book that ideas and principles are liberally illustrated by real field measurements. This serves to mitigate the overdependence on classical studies of sediment movement under steady flow conditions in rivers and laboratory flumes, which are of doubtful value, and possibly misleading, in the context of unsteady tidal flow. The author reveals his geology background by the text, in some instances misunderstand- ing and misrepresenting the engineering approach to tidal flow and sediment dynamics. This is particularly evident in the omission from the table of grain sizes of the different definitions commonly used by engineers. In compensation, the rest of this chapter provides an excellent reference explanation of methods of grain size analysis and the curious conventions that different disciplines use to present the results. The real value of this book lies in the assembly of information from many different sources. It provides an insight into not only the sediments themselves, but also into the processes which govern their movement and distribution. There is the most simple and succinct dissertation that I have ever read on how tides occur and the meaning of the principal tidal constituents, often quoted elsewhere without explanation. The clear descrip- tion of tidal propagation, tidal inequalities, and their combined effect on sediment distri- bution in estuaries is also without parallel. There are other text-books that provide more authoritative and comprehensive coverage of the separate topics included in this book, but none of them provide the broad sweep of the subject area in this way. With a generous list of references, Keith Dyer has provided a route by which the whole field of present knowledge of coastal and estuarine sediment dynamics can be entered, and for this reason alone it fully deserves a place on the bookshelf of the oceanographer, geologist, or engineer working in this field.