Changing river channels

Changing river channels

Book Reviews 365 culminating in a workshop in 1993, combined with extensive reviewing of the fmdings by many leading scientists, led to the producti...

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Book Reviews

365

culminating in a workshop in 1993, combined with extensive reviewing of the fmdings by many leading scientists, led to the production of this book in 1995. Following a very informative executive summary, the book comprises five chapters and two appendices. Chapter 1 provides an overview of what the freshwater imperative is in relation to the importance of water to society, how to address freshwater management issues, and the scope of the book. Chapter 2 deals with the status of freshwaters and the challenges ahead. Areas dealt with include biological impoverishment, manipulated hydrological regimes, and the threats to human health and the quality of life. Freshwater trends and challenges in an evolving world are considered. The important issues of changing demographic distribution, water resource consumption, environmental change, institutional and social values and information technology are also discussed. Chapter 3 considers the directions of freshwater research in relation to national water issues and human needs and the identification of priority research areas such as ecological restoration, protection of ecological diversity and predictive and prescriptive management. Chapter 4 links the scientific issues identified in the earlier chapters with management and policy. Here themes such as interfacing the natural human and management spheres and integrating them within a taslcsolving framework are dealt with. Important issues such as evaluation of best practice management and ecological approaches to environmental engineering are considered. Chapter 5 deals with the implementation needs including cost-benefit analysis within a strategic and management setting. The need for the enhancement of existing research programmes, the development of new institutions and the strengthening of education and communication links is also explored. The two appendices deal with (i) a list of research agenda participants and (ii) books and proceedings reviewed by the steering committee. The book is relatively short (165 pages), but a considerable amount of information is presented. While most of the presentations made are overviews, the clarity and soundness of the arguments shine through, and what could have been a boring administrative document has become a enjoyable read, couched in the much needed enthusiasm of the scientific researcher. I recommend the book to a wide enviromnental research audience and I hope that seeded by this work, equivalent studies are undertaken at the scientific policy level in countries other than that to which the book is addressed. COLIN NEAL (Wallingford, UK)

Changing River Channels by A. Gurnell and G. Petts (Editors), John Wiley, Chichester, UK, 1995, hardcover xviii + 442 pp., El 10.00, ISBN O-471-95727-5. This edited volume of requested papers represents both a celebration and a shop window. Firstly, it celebrates the distinguished career of Professor Ken Gregory who, over a period of more than 30 years, has contributed significantly to the field of fluvial

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Book Reviews

geomorphology. Much of his work has focused on the geomorphology of river channels and river channel change over various timescales. This volume is seen as an appropriate tribute to that research effort. Secondly, it serves as a shop window for the enthusiasm, inspiration and guidance which Ken Gregory has imparted, particularly to his postgraduate students, many of whom have themselves gone on to successful careers in the same field. More than half of the papers have been written by his former students, the remainder being contributed by colleagues and co-workers. Ken Gregory’s scientific standing, both nationally and internationally, has been recognised by the award of several medals, notably the coveted Founder’s Gold Medal of the Royal Geographical Society which he received in 1993. Following an introductory chapter by Petts which sets the scene in terms of the geographical approach to fluvial geomorphology, the papers are organ&d into four main sections, the overall appropriateness of which is questionable: ‘Temporal and Spatial Dimensions’, ‘Processes of Change’, ‘Information for the Management of Change’, and ‘Management for Change’. The first section includes papers on river channel change over time scales of 103-lo4 (Starkel; Brown) and lo’-lo* (Hooke; Park) years. Starkel covers familiar ground in dealing with change in European rivers during the Holocene, while Brown provides a useful review of floodplain change from a UK perspective, with emphasis on the identification of change and channel-floodplain coupling. More recent river channel adjustments are considered by Hooke and Park who respectively deal with the planform (notably meandering) and crosssectional dimensions. Sandwiched between these two sets of papers is a chapter by Gardiner on spatial and temporal variations in drainage density, a topic once close to Ken Gregory’s heart, Apart from the paper by Gomez which summarises the ‘equal mobility’ debate. in the context of both the entrainment and transport of heterogeneous bed material, the papers in the second section do not really focus sufficiently on the actions of processes to warrant the section title. Catchment-scale variations in sediment throughput and output are considered by Trimble and Walling via the sediment budget and sediment yield approaches respectively. Trimble presents five models which provide alternative perspectives on the magnitudes and timescales of sediment fluxes under different environmental conditions, while Walling brings his influential suspended sediment yield work up to date. The section closes with two papers (Keller and Macdonald; Gumell) on the interaction between vegetation and river channels, a theme with which Ken Gregory has been closely associated in recent years. Management issues are supposedly the concern of the remaining two sections. In the first there are papers on various techniques, including the application of remote sensing to the study of river channel change (Milton et al.), the information that can be obtained from topographic surveys (Downward), and the role of channel geometry equations in estimating flood discharges (Wharton). In addition, Downs considers how river channel classifications can assist planners and engineers involved in river management, focusing on those which emphasise channel adjustment. In the final section ‘sustainable development* is ‘a recurrent theme. Brookes examines current issues and future challenges surrounding river channel restoration against a background of widespread channelisation, while Gardiner looks at recent changes in

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strategic decision-making about the water environment in the light of Agenda 21 of the 1992 Rio summit. Finally, Newson makes his familiar plea for the closer integration of fluvial geomorphology and river engineering, with emphasis on the catchment scale. His remark that “Perhaps the most important current role for fluvial geomorphology is in informing (and in some cases restraining!) headlong moves for river restoration’* (p. 428) provides an interesting link with Brookes’ chapter. A wide range of subject matter is covered but, inevitably in a volume of 19 separate chapters, the depth and quality of treatment are highly variable. It is an admirable gesture to honour Ken Gregory in this way, but who is going to buy the book, particularly in view of the hefty price tag of El lo? Presumably it is aimed at the library market, but even so the price seems too high to pay for such a volume, especially since much of the material has appeared elsewhere in one form or another. There are some useful review chapters (one has over 170 references!) but generally there is not sul%cient material of a depth or novelty to recommend purchase. DAVID KNIGHTON (Sheffield, UK)

River, Coastal and Shoreline Protection by C.R. Thome, S.R. Abt, F.B.J. Barends, S.T. Maynord and K.W. Pilarczyk, John Wiley, Chichester, UK, 1995, hardback, 766 pp., E175.00, ISBN O-47194235-9. This well-produced and substantial hardback volume runs to 766 pages. It includes 47 papers that are an edited selection of those presented at the International Riprap Workshop held at Colorado State University, Fort Collins, CO, USA, in July 1993. It is subtitled Erosion Control Using Riprap and Armourstone, which describes the content more accurately than the general title as it is specifically flexible structures that are considered. As is pointed out in the preface, expenditure on the design and construction of these erosion control structures made from rock or concrete blocks is vast. This is not a widely served subject and this publication must, therefore, be a welcome addition to the available literature. The contributors represent the state of the art in this subject and, in the main, the different approaches and styles make for interesting comments in the discussion following almost all of the papers. As must be expected, not all points are resolved, but there is a satisfying sense of the interaction and feedback that arose from the workshop. This book addresses the important fundamental and practical problems concerned with the protection of waterways and coasts. It draws on international expertise and concentrates on the use of rock - a subject which is deserving of the thorough treatment given here. However, in dealing with the different aspects - hydraulic, geotechnical and material, and environmental - it provides a useful fusion of subjects that are often found only in separate sources. The book is aimed at both researchers and practitioners and has benefited from