Table Of ContentGIS, Computer Science DH
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Linked Data
A Geographic Perspective
“... this volume is a gem. ... It fully meets [the authors’] objective of being a practical L
guide to implementing solutions based on Linked Data and the Semantic Web that i
involve Geographic Information. The practical experience of the authors shines n
through ... . But my greatest praise is for its readability. To produce a book that is k
such a pleasure to read on ... such a technical topic is an outstanding achievement.
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... [Hart and Dolbear] have a rare talent for making complex concepts clear and the
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potentially dull sparkle.”
—Mike Jackson, PhD, FRICS, FRGS, Emeritus Professor for Geospatial D
Science, Nottingham Geospatial Institute, The University of Nottingham, UK
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Geographic Information has an important role to play in linking and combining
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datasets through shared location. The potential is still far from fully realized, but
developments in the Semantic Web and Linked Data are making it possible to A
integrate Geographic Information in a way that is more accessible to users.
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Drawing on the industry experience of a geographer and a computer scientist,
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Linked Data: A Geographic Perspective is a practical guide to implementing
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Geographic Information as Linked Data.
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In easy-to-understand terms, the authors explain the complexities of modeling a
Geographic Information using Semantic Web technologies and publishing it as p
Glen Hart • Catherine Dolbear
Linked Data. They also review the software tools currently available for publishing h
and modeling and provide a framework to help evaluate new tools in a rapidly i
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developing market. Throughout, extensive examples demonstrate how ontologies
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and Linked Data can be used to manipulate and integrate real-world Geographic
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Information data from multiple sources.
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A coherent introduction to a complex subject, this book supplies the durable p
knowledge and insight needed to think about Geographic Information through the e
lens of the Semantic Web. It provides a window to Linked Data for geographers, c
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as well as a geographic perspective for software engineers who need to under-
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stand how to work with Geographic Information.
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K13218
Glen Hart • Catherine Dolbear
Boca Raton London New York
CRC Press is an imprint of the
Taylor & Francis Group, an informa business
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What is written without effort is in general read without pleasure.
Samuel Johnson
We hope we have made enough effort to
bring some pleasure in reading.
Glen Hart and Catherine Dolbear
Contents
Preface......................................................................................................................xv
About the Authors ...................................................................................................xix
Chapter 1 A Gentle Beginning..............................................................................1
1.1 What This Book Is About and Who It Is For ............................1
1.2 Geography and the Semantic Web ............................................2
1.2.1 Geographic Information ...............................................2
1.2.2 The Semantic Web .......................................................3
1.3 GI in the Semantic Web .............................................................3
1.4 Examples ...................................................................................4
1.5 Conventions Used in the Book ..................................................5
1.6 Structure of the Book ................................................................7
1.7 A Last Thought about How to Read This Book ........................7
Chapter 2 Linked Data and the Semantic Web .....................................................9
2.1 Introduction ...............................................................................9
2.2 From a Web of Documents to a Web of Knowledge .................9
2.3 Early History and the Development of the Semantic Web ......12
2.4 Semantic Web Benefits ............................................................16
2.4.1 Data Integration ..........................................................16
2.4.2 Data Repurposing .......................................................17
2.4.3 Data Collection, Classification, and Quality Control ...17
2.4.4 Data Publishing and Discovery ..................................18
2.5 How It Works ...........................................................................19
2.6 Recent Trends in the Field .......................................................21
2.7 Summing Up and Signposts to the Next Chapter ....................23
Notes ...................................................................................................23
Chapter 3 Geographic Information .....................................................................25
3.1 Introduction .............................................................................25
3.2 What Is Geographic Information? ...........................................25
3.3 The Many Forms of GI ............................................................26
3.3.1 Geometry ....................................................................26
3.3.1.1 Raster ..........................................................26
3.3.1.2 Vector ..........................................................27
3.3.2 Topology and Mereology............................................28
3.3.3 Textual Representations .............................................29
3.3.3.1 Description ..................................................29
3.3.3.2 Classification ...............................................30
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viii Contents
3.3.3.3 Direction .....................................................31
3.3.3.4 Address .......................................................31
3.4 Representations and Uses of GI ...............................................33
3.4.1 Maps ...........................................................................33
3.4.2 Gazetteers ...................................................................35
3.4.3 Terrain Models and Three Dimensions ......................36
3.4.4 Digital Feature Models ...............................................36
3.5 A Brief History of Geographic Information ............................37
3.5.1 A Traditional Story: GI and GIS ................................37
3.5.1.1 Geographic Information Systems ...............37
3.5.1.2 Standards Develop ......................................40
3.5.1.3 The Web ......................................................40
3.5.1.4 Spatial Data Infrastructures ........................41
3.5.2 GI: A History of the Web and Spatial Coincidence ....42
3.5.2.1 Open Government Data ..............................46
3.5.3 The Formal and Informal Together ............................47
3.6 Summary .................................................................................49
Notes ...................................................................................................50
Chapter 4 Geographic Information in an Open World .......................................51
4.1 Introduction .............................................................................51
4.2 Principles .................................................................................51
4.2.1 Semantic Web .............................................................51
4.2.2 Geographic Information .............................................52
4.3 Applying the Semantic Web to GI ...........................................56
4.3.1 Example ......................................................................56
4.3.1.1 Obtain Appropriate Datasets ......................56
4.3.1.2 Load the Data .............................................57
4.3.1.3 Conduct the Spatial Analysis ......................57
4.3.1.4 Observations and Discussion ......................58
4.3.2 Topological Relationships ..........................................59
4.4 Important Observations ...........................................................61
4.5 Summary .................................................................................63
Notes ...................................................................................................64
Chapter 5 The Resource Description Framework ...............................................65
5.1 Introduction .............................................................................65
5.2 RDF: The Purpose ...................................................................65
5.3 A Word about Identity .............................................................66
5.4 The RDF Data Model ..............................................................67
5.5 RDF Serialization ....................................................................71
5.5.1 RDF/XML ..................................................................71
5.5.2 Turtle ..........................................................................75
