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management’ in the intervening decade. This has included major changes in agricultural policy, EA legislation, the formation of the NRA and a vastly improved attitude among river managers. What a comparison of the two handbooks does demonstrate, however, is that there has been no corresponding revolution in the principles and techniques of sympathetic river management. These were all broadly in place by 1984. There have been many refinements, notably in the techniques for erosion protection and the establishment of aquatic margins. There has also been a striking expansion of scale. Thus 7 km of the previously sterile River Torne near Doncaster has been enhanced with continuous aquatic margins whose colonization by plants and animals has exceeded all expectations. If you relate such examples to the inspirational research on buffer zones described for the River Leach, where a 99% retention of nitrates was demonstrated, the possibilities of seriously restoring river corridors begin to be apparent.

Perhaps the most spectacular case study is the flood storage system at Curry Moor on the Somerset Levels where the overspill of floodwater deliberately inundates 600 ha of farmland. This is also the oldest example in the book since date of origin is given as ‘Fourteenth Century’! The recent revolution has been the establishment of the Environmentally Sensitive Area (ESA) which has been able to reverse the previous trend away from such practices. In the winter since the handbook came out, the levels have been more flooded than ever and, although the farmers complain, they all know that they are now well paid to keep their feet wet.

A major theme of the handbook is the need to address river management in a holistic manner and it starts well with an account of river processes and the links between hydrology and ecology. However, an engineer using this book could be forgiven for assuming that amenity, the historic landscape and the simple visual impact of his schemes were of no relevance provided he catered for dragonflies and otters. It is unfair to accuse the authors of neglecting areas which were always outside their scope. This is explicitly a wildlife handbook and is already 100 pages longer than its predecessor, but I do think that all handbooks of this kind should carry some kind of warning about the context in which they are used.

In 1986, the designers of the Blackwater scheme in Northern Ireland had well-thumbed copies of the first

RSPB handbook in their hands, as with best intentions they set out to apply its recommendations to a scheme which dramatically transformed 21 8 miles of watercourse and drained up to 30 wetlands. Ten years later The Good Roads Guide which does for road engineers what the RSPB handbook does for river engineering, is equally conspicuous in the site offices at Twyford Down. The new handbook describes the narrowing of a stream at High Wycombe in order to compensate for low flows. The case in point was probably validated by its benefits to crayfish, but as a general principle, artificially halving the width of streams in order to make do with less water, rather than dealing directly with the problems of over-abstraction may be seen as a cop-out, and similar proposals were firmly rejected as such on the River Darent.

These are obvious examples but the context of river management can pose more subtle pitfalls. I recently revisited a scheme where I had radically extended and altered an existing pond in the interest of habitat enhancement. It now transpires that before I got my hands on it, this had been an excellent example of a rectangular Roman fishpond. For the benefit of wildlife, I had blithely vandalized a piece of heritage. Gung-ho enhancement in the early days was a major reason for the subsequent emphasis on survey, of which the NRA now holds a superb database, and on which there is a much expanded section in the new handbook. Yet surveys also have their dangers. Politicians in the water industry would probably find it more convenient if their environmental sections quietly concentrated on surveys which are subsequently locked away in filing cabinets, rather than bother engineers and landowners with elaborate proposals for actually changing things on the river bank. One glance at the range of possibilities in this handbook, combined with the melancholy miles of still un-reconstructed river in East Anglia and the Vale of York to name but two areas where enhancement has hardly taken off, makes it clear how badly needed the new handbook is, and how much work is still needed to put its principles into practice.

JEREMY PURSEGLOVE Mott MacDonald,

Cambridge, UK

THE RIVERS HANDBOOK. HYDROLOGICAL principles into practice’. In spite of the title ‘Handbook’, it AND ECOLOGICAL PRINCIPLES, VOLUME 2, consists of 25 review chapters and provides an especially edited by Peter Calow and Geoffrey E. Petts, wide range of articles on hydrology, modelling and Blackwell Scientific Publications, Oxford, 1994. ISBN management within a single cover, including a number of 0 632 029854 subjects reviewed fully for the first time. There is little

overlap between chapters in this or the previous volume. The first part of this two-volume book dealt with general Part 1 ‘Perturbations and Biological Impacts’ starts scientific and ecological principles. This second ‘puts with a well-written review by one of the editors (Petts)

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on ‘Rivers: Dynamic components of catchment ecosystems’, which provides a useful introduction to many of the hydrological topics discussed later in the book. Similarly, ‘River Pollution’ (R. A. Sweeting) gives a concise introduction to biological problems. The editors emphasize that Part 2 ‘Monitoring Programmes’ is not intended to deal with all aspects of monitoring in river management. It includes two general chapters, with important topics such as the collection of baseline data and the statistical analysis of water-quality data, and one of the most detailed chapters in the book, ‘Biological water-quality assessment of rivers: use of macroinvertebrate communities’ (J. L. Metcalfe-Smith). Although the last is an excellent overview, the Handbook nowhere assesses the full range of biota useful for monitoring and the various ways in which information from them can be used.

Part 3 ‘Modelling: Forecasting and Prediction’ includes four chapters dealing with essentially hydrological topics, one on ‘Water quality modelling’ (P. Crockett) and one on ‘Prediction of biological responses’ (P. D. Armitage). The chapters all succeed well in doing what they set out to do, though there is little mention of nutrient chemistry or phytoplankton, two subjects which are currently the focus of modelling efforts in many rivers. A further chapter summarizing a case study would also have been useful. Part 4 ‘Management Options’ focuses on the approaches for solving or mitigating problems raised earlier in the book. ‘Flow allocation for in-river needs’ (G. E. Petts and I. Maddock) and ‘Water-quality control’ (A. J. Dobbs and T. F. Zabel) are general overviews likely to be of particular help to ecologists concerned with river management. The latter chapter is a good place to look for information on EC directives on standards and

related topics, though there is relatively little about other continents. In contrast, ‘Management of macrophytic vegetation’ (P. M. Wade) incorporates information from a very wide range of countries.

Part 5 ‘Case Studies’ deals with two rivers in detail (Upper Mississippi by J. L. Rasmussen and R. Laxa, Iceland, by G. M. Gislason) and then finishes with a broad review ‘Dryland Rivers: Their Ecology, Conservation and Management’ (B. R. Davies, M. C. Thomas, K. F. Walker, J. H. OKeeffe and J. A. Gore). This last is an excellent conclusion to the Handbook, because it brings together many of the topics reviewed earlier and ends with brief, but perceptive, observations on management and research priorities.

The book is produced to a high standard. The text is presented clearly, with a uniform format throughout the book and is virtually free of trivial errors, though the diagrams are sometimes unnecessarily large. Most of the chapters are fully up to date, and several authors manage to insert a 1994 reference. There is a useful index to this volume, but a combined index for the two volumes would have been helpful. Overall I found this volume much more useful than the first one. Whereas the quality of chapters in Volume 1 is uneven, those in Volume 2 are consistently of a high standard. Neither volume provides the detailed lists of information about rivers and river management that might be expected from a handbook. Nevertheless, I strongly recommend anyone concerned with applied aspects of rivers to obtain the second volume, whether or not they have the first one.

BRIAN WHITTON Department of Biological Sciences,

University of Durham, UK