Linked Data: A Geographic Perspective

271 Pages·2013·4.595 MB·English

by  Glen Hart, Catherine Dolbear

GIS, 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
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What is written without effort is in general read without pleasure.
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We hope we have made enough effort to
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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