Object-Oriented Design for Temporal GIS Object-Oriented Design for Temporal GIS MONICA WACHOWICZ UK USA Taylor & Francis, 11 New Fetter Lane, London EC4P 4EE Taylor & Francis Inc., 1900 Frost Road, Suite 101, Bristol, PA 19007 Copyright © Taylor & Francis 1999 Taylor & Francis is an imprint of the Taylor & Francis Group This edition published in the Taylor & Francis e-Library, 2003 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, electronic, electrostatic, magnetic tape, mechanical, photocopying, recording or otherwise, without the prior permission of the copyright owner British Library Cataloging in Publication Data A catalogue record for this book is available from the British Library ISBN 0-203-21239-8 Master e-book ISBN ISBN 0-203-26977-2 (Adobe eReader Format) ISBN 0-7484-0831-2 (cased) Library of Congress Cataloging-in-Publication Data are available Cover design by Hybert Design and Type, Waltham St Lawrence, Berkshire Cover printed by Flexiprint, Lancing, West Sussex Contents Series Introduction Preface Acknowledgements ix xi xiii Introduction 1.1 Object-oriented analysis and design 1.2 Spatio-temporal data in GIS 1.3 Time geography 1.4 The spatio-temporal data model 1.5 Aims of this research 1.6 Organisation of this book Concepts of space and time 2.1 The space-dominant view 2.2 The time-dominant view 2.3 The absolute space-time view 2.4 The relative space view 2.5 The relative time view 2.6 The relative space-time view 2.7 Choosing the view for a GIS 2.8 Time geography 2.9 Time geography and GIS 2.10 Main elements of a space-time path 2.10.1 State as an element of the space-time path 2.10.2 Event as an element of the space-time path 2.10.3 Episode as an element of the space-time path 2.10.4 Evidence as an element of the space-time path v 7 9 11 12 13 13 14 16 16 19 20 21 22 24 24 vi CONTENTS 2.11 2.12 Uncovering space-time paths Conclusions Object-oriented analysis and design 3.1 History of the object-oriented paradigm 3.2 Choosing an object-oriented method 3.3 The main modelling constructs 3.4 Temporal databases 3.5 Version management approaches 3.6 Conclusions 24 25 27 27 32 36 39 43 43 04 The spatio-temporal data model 4.1 Defining the reasoning task 4.2 The space-time configuration 4.3 Data model changes 4.4 Connectivity aspects 4.5 Version management 4.6 Conclusions 45 46 47 48 49 50 52 Applying the STDM: public boundaries evolution 5.1 Public boundary record maintenance 5.1.1 The knowledge domain 5.1.2 The space-time path 5.2 Evolution in definition 5.3 Four main scenarios 5.3.1 Public boundary entry scenario 5.3.2 Evolution tracking scenario 5.3.3 Update scenario 5.3.4 Archiving scenario 5.4 Version management 5.5 Conclusions 55 55 56 57 61 63 64 68 73 74 77 78 Implementation of the STDM 6.1 Smallworld GIS 6.2 Public boundary entry scenario 6.3 Evolution tracking scenario 6.4 Update scenario 6.5 Archiving scenario 6.6 Historical views 6.7 Conclusions 81 81 83 87 90 92 92 94 Emerging technologies 7.1 Spatio-temporal objects in database systems 7.2 Knowledge discovery in databases 97 97 98 CONTENTS 7.3 7.4 Geographic visualisation Ubiquitous computing Appendix A Appendix B Appendix C References Index Notation for Booch’s method Depicting public boundaries on OS basic scales Overview of the spatial data model vii 99 100 101 103 105 107 115 Series Introduction Welcome The Research Monographs in Geographical Information Systems series provides a publication outlet for research of the highest quality in GIS, which is longer than would normally be acceptable for publication in a journal The series includes singleand multiple-author research monographs, often based upon PhD theses and the like, and special collections of thematic papers The need We believe that there is a need, from the point of view of both readers (researchers and practitioners) and authors, for longer treatments of subjects related to GIS than are widely available currently We feel that the value of much research is actually devalued by being broken up into separate articles for publication in journals At the same time, we realise that many career decisions are based on publication records, and that peer review plays an important part in that process Therefore a named editorial board supports the series, and advice is sought from them on all submissions Successful submissions will focus on a single theme of interest to the GIS community, and treat it in depth, giving full proofs, methodological procedures or code where appropriate to help the reader appreciate the utility of the work in the monograph No area of interest in GIS is excluded, although material should demonstrably advance thinking and understanding in spatial information science Theoretical, technical and application-oriented approaches are all welcomed The medium In the first instance the majority of monographs will be in the form of a traditional text book, but, in a changing world of publishing, we actively encourage publicationon ix x SERIES INTRODUCTION CD-ROM, the placing of supporting material on web sites, or publication of programs and of data No form of dissemination is discounted, and prospective authors are invited to suggest whatever primary form of publication and support material they think is appropriate The editorial board The monograph series is supported by an editorial board Every monograph proposal is sent to all members of the board which includes Ralf Bill, António Câmara, Joseph Ferreira, Pip Forer, Andrew Frank, Gail Kucera, Enrico Puppo, and Peter van Oostrom These people have been invited for their experience in the field, of monograph writing, and for their geographic and subject diversity Members may also be involved later in the process with particular monographs Future submissions Anyone who is interested in preparing a Research monograph, should contact either of the editors Advice on how to proceed will be available from them, and is treated on a case by case basis For now we hope that you find this, the fifth in the series, a worthwhile addition to your GIS bookshelf, and that you may be inspired to submit a proposal too Editors: Professor Peter Fisher Department of Geography University of Leicester Leicester LE1 7RH UK Phone: +44 (0) 116 252 3839 Fax: +44 (0) 116 252 3854 Email: pff1@le.ac.uk Dr Jonathan Raper Department of Information Science City University Northampton Square London EC 1V 0HB UK Phone: +44 (0) 171 477 8415 Fax: +44 (0) 171 477 8584 Preface A wide spectrum of research areas have contributed to the development of objectoriented analysis and design methods Within computing sciences objectorientation has been developed in the fields of databases, programming languages, and system engineering Some indications of this development include the proliferation of objectoriented concepts, notations, models, and application areas This book provides a much-needed geographic perspective to enhance both the development and understanding of object-oriented methodology In particular, it addresses how both Time Geography and the object-oriented methodologies can be integrated to represent and manipulate space and time in GIS Time Geography provides a conceptual framework for capturing the semantics of space and time This book introduces the reader to the framework abstractions developed in Time Geography They are of primordial importance for handling spatiotemporal data in GIS They play an important role as a modelling tool for representing the passage of time and the mechanisms of change The book explains how the time geographic abstractions can be integrated with the modelling constructs of objectoriented analysis and design methods This is achieved by describing a spatio-temporal data model designed to address the complex and subtle semantics of space and time of historical data The logical components (schema evolution, data update procedures, events) and the physical structure (storage structure, access methods, multidimensional indexing) of the spatio-temporal data model are also described in the book This book is not an introduction to object-orientation There already exists a vast literature regarding this subject The motivation for this book is the relative absence of research in the field of integrating spatio-temporal data modelling, object-orientation and GIS Therefore, the book offers a practical guide to object-oriented modelling constructs and demonstrates the feasibility of applying them to the problem of modelling spatio-temporal data It encourages readers to apply and explore objectoriented analysis and design methods by presenting a variety of practical examples in xi xii PREFACE the application area of political boundary record maintenance (historical data) A prototype implementation of the spatio-temporal data model into the Smallworld GIS illustrates the results of the processes involved in boundary making of public boundaries in England This book is a revised and summarised version of my doctoral thesis submitted to the Department of Geography at the University of Edinburgh It is intended for readers from multi-disciplinary research areas It is required reading for all those interested in the role of object-orientation for integrating space and time in GIS The book is essential reading for students, scientists and researchers in the fields of Geography, GIS, Cartography, and Databases It begins with a synopsis of space and time concepts, their application in GIS, and the functional requirements to develop a temporal GIS A variety of applications and the characteristics of their spatio-temporal data are described A literature review is included on Time Geography, temporal GIS and the object-oriented paradigm (programming languages, analysis and design methods, databases) Future research directions are outlined in spatio-temporal data modelling, version management, and applications with complex and interrelated objects and spatio-temporal data This book provides an objective source of references for addressing conceptual, methodological, and technical issues for handling spatio-temporal data in GIS The object-oriented analysis and design method developed by Booch is used in this book This method has been the most widely accepted in the database research and development communities The synergy of Time Geography, object-orientation and GIS is illustrated by a prototype implementation Finally, the last chapter discusses issues that are emerging as important areas of technological innovations in GIS Knowledge Discovery in Databases (KDD), geographic visualisation (GVis), and ubiquitous computing reinforce the use of the object-oriented methodology in GIS I have attempted to provide the reader with an understanding of the issues in the object-oriented design of a temporal GIS and have taken a position on most of them: comments, corrections, and suggestions welcome Acknowledgements I am thankful to several people who encouraged me in one way or another to realise the original thesis which led me to write this book First of all, I would like to thank my supervisors, Professor Richard G.Healey and Professor Michael F.Worboys, for their unceasing support and valuable advice during my thesis research My thanks also go to Les J.Rackham and Alan Hardiman of the Ordnance Survey, who have significantly contributed in expanding my knowledge on the evolution of public boundaries in Great Britain The Department of Geography at the University of Edinburgh has provided a stimulating environment in which to work and my thanks go to those who helped to make it that way In particular, I would like to thank Steve Dowers and Chris Place for their support and expertise on computing facilities in the Department, and I would like to thank Penny Leg for making my research meetings with Richard possible I was fortunate to find many colleagues in Edinburgh who were willing to listen to my ideas; in particular Bhaskar Ramachandran, Trevor Rotzien, Charles Stewart, Jonathan Makin and Christoph Corves who provided thought-provoking discussions and suggestions I would like to thank Marianne Broadgate, Vicen Carrio-Lluesma, Juan Suarez, Manoel Claudio da Silva, Marcelo Vieira, Gwo-Jinn Hwang, Xuan Zhu and Bod Hodgard for their friendship and endless support during my years in Edinburgh The Research monographs in Geographical Information Systems series has provided me with the possibility of publishing my thesis, and I would like to thank Professor Peter Fisher and Doctor Jonathan Raper for the opportunity of transforming my thesis into this book I am grateful for the financial support and encouragement I have received from my family Distance could never deter them from being a continuous source of love and reassurance At the risk of under-expressing my gratitude, I would like to thank my husband Victor for his unconditional optimism, continuous source of love and support This book is dedicated to them xiii ... space-time path 2 .10 .3 Episode as an element of the space-time path 2 .10 .4 Evidence as an element of the space-time path v 7 9 11 12 13 13 14 16 16 19 20 21 22 24 24 vi CONTENTS 2 .11 2 .12 Uncovering... Design for Temporal GIS Object-Oriented Design for Temporal GIS MONICA WACHOWICZ UK USA Taylor & Francis, 11 New Fetter Lane, London EC4P 4EE Taylor & Francis Inc., 19 00 Frost Road, Suite 10 1,... xi xiii Introduction 1. 1 Object-oriented analysis and design 1. 2 Spatio -temporal data in GIS 1. 3 Time geography 1. 4 The spatio -temporal data model 1. 5 Aims of this research 1. 6 Organisation of