Water sources run through it

This book is about water on land, ie not water in the oceans. It covers, in a popular way, a large sector of the scientific field of hydrology. Hydrology is a huge interdisciplinary field of interest to a wide spectrum of the public. The subject ranges from the properties of water to the hydraulics of water waves moving in river channels and their impacts on river channel geometry, from the farmer irrigating his crops to the industrialist requiring clean water inputs to his processes. As a consequence, the subject is of interest to virtually all levels of education from primary schools to postdoctoral research.

E. C. Pielou manages to span this enormous spectrum of material and levels in a single book by a very careful selection of material and treatment. The difficult problems are not avoided, so that unsaturated zone hydrology and the origin of meanders get fair treatment at a level that will be comprehended easily by average A-level students. Even degree-level students in environmental studies will find it sufficiently informed. The book is well illustrated by the author's own clear sketches designed to bring out the essentials. Each chapter has an adequate follow-up reference list. The writing is informal, fluid and rarely misleading.

As a naturalist of international standing, Pielou brings an ecological dimension that is often lacking in hydrology books. A special feature of the book is the interest in snow, ice and glacial landscapes and the "backwoodsman" feeling on practical aspects of water resources. The boreal zone gets good handling. Not so the semi-arid, tropical and desert environments, except in the context of groundwater problems. Pielou seems to inhabit a world where human concerns for the major life resource attract little attention. Not for her the great drought crises of lower latitudes, the recurrent flood problems of the great tropical rivers, or the ceaseless effort to find a suitable mechanism for constraining water consumption in the world's advanced and developing economies. The words drought, deserts and desertification hardly feature in the book. There is not too much interest in flooding, but water quality is well covered.

On the whole, this failure to address the human dimensions of water is the book's main drawback. Water conflicts at local, state and international level are as much a part of the issue as the debate about catchment-versus-channel management of water resources.

Indeed, I would argue that the solution of the future global crises in water resources will revolve more around society's capacity to handle the human dimensions of the problem than around hotly debated model parameterisation. National institutions need to address these pressing issues in hydrological sciences. They cannot be shrugged off as "soft science". In future editions of her book, Pielou also needs to pay them more attention.

This book deserves to be successful across the educational spectrum. Why not a cheaper paperback edition, at a third of the cost, so that it is more accessible to the broader educational market?

John Thornes is professor of physical geography, King's College, London.