88 Book Reviews

at around 750 tniles a year, other 5ources suggest a figure around 5000 miles ayear! Such discrepancies arise because of the lack of ground survey and the subjectivity involved in defining ‘hedgerows’.

The report ends with a useful summary and an extensive reference list. This publication is of value to anyone studying countryside change and con- ccrned with the problems of elucidating such change from different sources of information. Its mainlimitation is that thereasonsfot lossorchange in the structure of woods, trees and hedges are not considered.

Louise Heathwaite Depuriment of Geogrphy, Univerxiiy of Sheffield

Bracken, 1. and Webster, C. f~lfort~ff~~on tech- nology in geographv and planning. London: Routledge, 1990. 444 pp. f60 hardback.

Information technology is changing so rapidly that there are frequent needs for new textbooks to draw together scattered material into single reference works. The art is to select the right material at an appropriate level to fulfil those needs.

Part One of this book sets the context, beginning with a chapter on geographic data. There is a detailed section on information theory, which is, however, treated as a statistical exercise unrelated to applications. Chapter 2, on the hardware environment, goes from the almost obligatory a~kno~viedgemen[s of Babbage, etc., through the basics of binary arithmetic, to character strings produced by a digitizing tablet.

Part Two is on the acquisition and organization of geographic data. 1 would personally have pre- ferred to see Chapter 5, on data structures, pre- ceding Chapters 3 and 4 on data capture and retrieval respectively, particuiarly as the authors blur from one into another. Data retrievat (Chapter 4) includes the use of 1981 Census data and SASPAC. There are skcletai pointers to local authority systems such as LAMIS, and a short introduction to Ordnance Survey digital map data.

i find the low level of attention paid to these somewhat surprising. Chapter 5 is a good account of data 5tructures.

In Part Three, the manipulatioil of data is addressed, first in Chapter 6 by looking at basic VDU graphics. Many of the operations described in this chapter, such as affine transformation, rotation, etc., belong mote with the vector tech- niques explored in Chapter 7, a useful chapter including generalization, polygon building, overlay, etc. Chapter 8 looks at raster techniques.

Part Four incudes Chapter 9 on non-carto- graphic and Chapter 10 on cartographic and related software. It is questionable whether the 22 pages on SPSSx and MINITAB would be more used by an undergraduate than manuals and leaflets available in almost any computing centre. A section on the itse of spreadsheets for specific tasks such as quadrat analysis and population forecasting is rendered more useful by not being package specific. Chapter IOsummarizesGlNOandGKS: GlMMSis used to exemplify a mapping system and various GIS systems and functions are mentioned. Finally, in a short postscript, four GIS systems are reviewed.

This volume is ambitious and perhaps the authors have tried to encompass too much. The result is very uneven levels of treatment given to different areas and in too many parts there is a sense of superficiality. It is apparently aimed at British rather than international readers-who e!se would understand ‘BBC (modeO)‘-but despite its title it IS not obvious as a book for planners. The frequent use of pseudo-code to describe algorithms without always giving full explanation of what is acrualll being done is probably of most value to reader, who might wish to translate the code into a computer language.

Lept I sound too critical, 1 think that there arc many sections of this book which will prove invaluable as sources of reference in geographic data handling and GlS for several years to come.

Atlan Jones Deporfment of Geographicul Sciences, Polytrchnit Soitrh West