UK IlfcWtt Principles of Geographical Information Systems Peter A. Burrough and Rachael A. McDonnell V Spatial Information Systems and Geostatistics Principles of Geographical Information Systems Spatial Information Systems and Geostatistics General Editors P. A. Burrough M. F. Goodchiid R. A. McDonnell P. Switzer M. Worboys Other books in the series Anthropology, Space, and Geographic Information M. Aldenderfer and H. D. G. Maschner Spatial and Temporal Reasoning in Geographic Information Systems M. J. Egenhofer and R. G. Golledge (eds.) Environmental Modeling with GIS M. Goodchiid, B. O. Parks, L. Steyaert (eds.) Managing Geographic Information Systems Projects W. E. Huxold and A. G. Levinsohn GIS County User Guide: Laboratory Exercises in Urban Geographic Information Systems W. E. Huxold, P. S. Tierney, D. R. Turnpaugh, B. J. Maves, and K. T. Cassidy Introduction to Disjunctive Krigingand Non-linear Geostatistics J. Rivoirard Principles of Geographical Information Sy st e m s Peter A. Burrough Rachael A. McDonnell OXFORD UNIVERSITY PRESS 1998 Oxford University Press, Great Clarendon Street, Oxford 0x2 6dp Oxford New York Athens Auckland Bangkok Bogota Bombay Buenos Aires Calcutta Cape Town Dar es Salaam Delhi Florence Hong Kong Istanbul Karachi Kuala Lumpur Madras Madrid Melbourne Mexico City Nairobi Paris Singapore Taipei Tokyo Toronto Warsaw and associated companies in Berlin Ibadan Oxford is a trade mark of Oxford University Press Published in the United States by Oxford University Press Inc., New York © Peter A. Burrough and Rachael A. McDonnell 1998 The moral rights of the authors have been asserted First published 1998 Reprinted with corrections 1998 All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, without the prior permission in writing of Oxford University Press. Within the UK, exceptions are allowed in respect of any fair dealing for the purpose of research or private study, or criticism or review, as permitted under the Copyright, Designs and Patents Act, 1988, or in the case of reprographic reproduction in accordance with the terms of the licences issued by the Copyright Licensing Agency. Enquiries concerning reproduction outside these terms and in other countries should be sent to the Rights Department, Oxford University Press, at the address above This book is sold subject to the condition that it shall not, by way of trade or otherwise, be lent, re-sold, hired out or otherwise circulated without the publisher’s prior consent in any form of binding or cover other than that in which it is published and without a similar condition including this condition being imposed imposed on the subsequent purchaser British Library Cataloguing in Publication Data Data available Library of Congress Cataloging in Publication Data Burrough, P. A. Principles of geographical information systems / Peter A. Burrough and Rachael A. McDonnell. p. cm. — (Spatial information systems) Rev. edn. of Principles of geographical information systems for land resources assessment. Includes bibliographical references and index. I. Geographic information systems. I. McDonnell, Rachael. II. Burrough, P. A. Principles of geographical information systems for land resources assessment. III. Title. IV. Series. G70.212.B87 1997 910'.285—dc21 97-25863 ISBN 0-19-823366-3 ISBN 0-19-823365-5 (Pbk) 10 98765432 Printed in Great Britain on acid-free paper by Butler & Tanner Ltd, Frome, Somerset To Joy, Alexander, Nicholas, and Gerard Digitized by the Internet Archive in 2018 with funding from Kahle/Austin Foundation https://archive.org/details/principlesofgeogOOOOburr Preface As with the first edition (Burrough 1986), this book describes and explains the theor¬ etical and practical principles for handling spatial data in geographical information (GI) systems. In the mid-1980s these computer tools were being developed from com¬ puterized aided design packages and computer-aided manufacturing packages (CAD- CAM), from automated mapping systems, and from programs for handling data from remotely sensed images collected by sensors in satellites, and there was a need to pro¬ vide a text that covered the common ground. Since then, sales of GIS as commercial products for the mapping and spatial sciences and for the inventory and management of spatial resources of cities, states, or businesses have increased phenomenonaily. People have become fascinated by the power of immediate interaction with electronic representations of the world. The development of the cheap, powerful personal com¬ puter has facilitated this process and the current ability to link computers by electronic networks across the globe has provided a ready source of all kinds of data in electronic form, including maps and raster images taken from all kinds of platforms from satel¬ lites to hovercraft to deep-sea vehicles. Today, not just maps are made using GIS, but the infrastructure of utilities (cables and pipes) in the streets of your town will be held in a GIS, your taxis and emergency services may be guided to their destinations using satellite-linked spatial systems, the range of goods in your shops may be decided by systems linking customer preferences to neighbourhood and socio-economic status, the foresters and farmers will be mon¬ itoring their stands and crops with spatial information systems, and a whole range of scientists and technicians will be advising governments, the military, and businesses from local to world scale how best to deal with the distribution of what interests them most. The ready provision of powerful computing tools, the increasing abundance of spatial data, and the enormous diversity of applications that are not just limited to map-making or scientific enquiry, make it even more important today than in 1986 to understand the basic principles behind GIS. Everyone thinks they understand GIS because they think they understand maps. But to understand a map is to understand how a person once observed the world, how they formulated imperfect, but plausible models to represent their observations, and how they decided to code these models on paper using conventional semiology. All these processes depend strongly on cul¬ ture, on age, on discipline, and on background. With GIS we go even further down a path in the labyrinth that leads from perception to presentation of spatial informa¬ tion, because though computers can mimic human draughtsmen, they can do so only according to the ways they are programmed. The basic tenets of spatial interactions needed to describe a given spatial process or phenomenon may or may not be shared by the ground rules of the GIS you would like to buy. But electronic GIS provide an enormous wealth of choice not possible with conventional mapping. Whereas with conventional mapping (and even the earliest digital mapping) the map was the data¬ base, today the map is merely an evanescent projection of a particular view of a spatial database at a given time. On the one hand this gives us enormous power to review an unlimited number of alternatives and to make maps of anything, anyway we like, including dynamic modelling of spatial and temporal processes; on the other hand it may leave us swimming in the dark. This book aims to provide an introduction to the theoretical and technical prin¬ ciples that need to be understood to work effectively and critically with GIS. It is based on the 1986 volume, but is much more than a simple second edition. The text examines the different ways spatial data are perceived, modelled conceptually, and represented. It explains how, using the standard ‘entity’ and ‘continuous held’ approaches, spatial data are collected, stored, represented in the computer, retrieved, analysed, and dis¬ played. As with the first edition, this material is accompanied by a critical evaluation of the sources, roles, and treatment of errors and uncertainties in spatial data, and their possible effects on the conclusions to be drawn from analyses carried out with GIS. Also included is a discussion of the principles and methods of dealing with uncertainty in spatial data, either through the probabilistic medium of geostatistics, or the possibilistic route using fuzzy logic. The principles of the latter are juxtaposed with the crisp concepts underlying the entity and field models so commonly used. Frequently encountered, specialist terms are explained in the glossary. Spatial analysis and GIS are nothing without computer software, and the material in this book could not have been produced without recourse to many different pro¬ grammes. Large, commercial systems may be unsuitable or unusable for teaching or scientific enquiry, and in Appendix 2 we provide information about sources of cheap or free software that have been used in preparing this book and which may be used to support training courses and research. GIS is truly interdisciplinary and multidisciplinary, and the literature is spread over a range of journals. Trade journals such as GIS World, and GIS Europe, provide monthly coverage of technical and organizational developments; trade shows and conferences and scientific journals such as the International Journal of Geographical Information Systems, Computers and Geosciences, Computers, Environment and Urban Systems, Geoinformation, and Transactions in GIS, cover the core of the field, though much is published in discipline-specific journals, and also in ‘grey’ literature reports from con¬ ferences, institutes, and commerce. We have not covered everything in this volume: that is impossible, but we aim to provide a basic technical and scientific introduction to an important scientific and business activity, so that readers will better understand how GIS are being used to transform the ways in which much of our world is per¬ ceived, recorded, understood, and organized. P.A.B. & R.A.McD. Utrecht February 1997