108 JOURNAL OF QUATERNARY SCIENCE

Principles of geographical information systems for land resource6 assessment

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P. A. BURROUGH

Publisher Oxford University Press 1986 (paperback) (1 93 pp) ISBN 0 19 854592 4

Published as the twelfth in the Monographs on Soil and Resources Survey series, this volume covers a subject of more general interest than many of the others. The book aims to describe the principles of geographical information systems (GIS) - powerful computer systems designed to capture, manipulate and analyse spatial information - which are impor- tant for environmental analysis and land resources evaluation and management. It is the first text published specifically on geographic information systems and as an introductory text does well to cover the field. For many years computer systems have been available to perform simple forms of spatial analysis, such as contouring and the production of simple thematic maps, and statistical analysis, using packages such as MINITAB or SPSS. Geographical or Land Information Systems represent the extension and integration of these forms of analysis and are recognised as one of the most rapidly developing fields in geography and cartography.

The book can be divided into five main sections. The first deals with the development of GIS from computer assisted mapping packages and the main components of these systems. This section includes a brief history of mapping and the reasons behind the development of computer assisted cartography and ultimately general-purpose geographical information systems. The main computer hardware components and peripherals associated with a GIS are described along with basic software modules commonly found in a GIs. The second section covers, in three chapters, the data structures employed by geographic information systems, digital elevation models and the storage, verification and display of spatial information. The first of these chapters is probably of only limited interest to those not concerned with the implementation of a spatial data base. The data structures are described clearly, however, and the use of numerous figures greatly assists understanding of some of the more complex structures. Similarly, the chapter on digital elevation models deals with the methods of generating and storing elevation data. The different types of analysis that can be performed using elevation data are also examined and exam- ples are given of many of the different types of output which can be produced. The last chapter in this section describes the various methods of data input, verification, storage and output.

Thechapters in thethird section deal with spatial analysisand dataquality. Thecapabilitiesofa CIS which distinguish it from a system for computer-assisted cartography are its abiity to analyse and integrate spatial data. Approaches to linking and integrating spatial data are described and three examples of modelling applied to land evaluation in a developing country are provided. The chapter discussing data quality, errors and the natural variation is perhaps the finest in the book. Although such errors are unavoidable in the collection and processing of spatial data, their influence is often calculable and the chapter describes many of the techniques for doing so. The full spectrum of errors ranging from positional accuracy to the statistical nature of boundaries are covered and clearly explained with the assistance of numerous figures and exam p lest

The fourth section is concerned with data classification and the methods of spatial interpolation. Classification groups together associated areas to clarify patterns, simplify analysis or assist presentation. Methods for achieving classification are described and some simple guidelines for classifying data are provided. The chapter on spatial interpolation (techniques for estimating the value of properties at unsampled sites within an area covered by existing point observations) provides a comprehensive review and a useful comparison of methods. The final section provides an informed view on how to select the most suitable GIS for a particular application and would be of use to the individual or organisation interested in acquiring a system.

Throughout the text is well written, clear, and the descrip- tions are well referenced and illustrated. The book i s essential reading for anyone who intends to use a computer to display or analyse spatially referenced data, and has an appeal far wider than might be implied by its inclusion in a soil monographs series.

NICHOLAS GREEN Birkbeck College

University of London Gresse Street

London W1 P 7 PA England

Palaeosols, their recognition and interpretation EDITED BY V. PAUL WRIGHT

Publisher Blackwell Scientific Publications, Oxford 1986 f27.50 (hardback) (330 pp) 130 illustrations ISBN 0 632 0133 62

Here, at last, we have a book concerning pre-Quaternary palaeosols! In the study of Quaternary sequences, palaeosols have become a standard tool and as such are well documented. It is now evident that palaeosols are abundant in the pre- Quaternary geological record and even Pre-Cambrian types are now widely recognised.

G. Retallack gives a stimulating review of the geological story of soils, beginning his discussion with the early evolution of the Earth and speculation on its earliest soils in comparison to those on the Moon, Venus and Mars. The study of these Pte-Cambrian soils provides information on the development of the early atmosphere. It outlines some of the major events which occurred during the evolution of the biosphere. Even though a biologically active soil cover, probably cryptogamic, almost certainly existed long before the late Silurian, the rise of vascular plants in the middle Palaeozoic must have had an enormous impact on soils, just as i t does now in the high Arctic environment. In the Upper Palaeozoic, extensive aforestation occurred which also led to an increased variety of soils, and the appearance of grasses in the Tertiary led to a further diversifi- cation of soil types.

It may be necessary to take a non-uniformitarian approach, looking at these palaeosols from a process-based viewpoint rather than trying to fit them into a classification of present day soils as is usually done by most Quaternary and Tertiary palaeopedologists. C. Percival’s paper shows clearly the use of vertical modifications (structure, granulometry. weathering