Geography represents a critical unifying dimension enabling disparate information to be linked to geospatial representations of spatial objects. Well-structured, semantically explicit and reliable geospatial information is required in the Web of Data by tools and applications beyond those used by traditional geospatial practitioners. However, providing reliable identifiers for spatial objects is problematic for a number of reasons. Firstly, spatial objects are typically referenced using codes or names which are ambiguous. Use of names is particularly problematic since a place may have many names and the same name may refer to many places. Codes are reliable only in the context of the system in which they are defined and as there is no standardized way of declaring this context, these codes cannot be reliable used to reference spatial objects across systems. Secondly, data systems may have multiple representations of the same spatial object each with a different geometric representation and identifying code. Finally spatial objects change over time, requiring new versions of data with changes to name, code, geometry and other attributes that characterize the spatial object. Despite this complexity, there is a need to be able reliably identify, cite and obtain information about spatial objects. It may be necessary to cite either a concept or a specific versions of a representation. Such representations may record different geometries (e.g. point and polygon) at different scales available in different formats, each of which may be valid for a particular use case. The Spatial Identifier Reference Framework (SIRF) described in this presentation, addresses the spatial identifier challenges articulated above. SIRF allows spatial objects to be discovered and interrogated using web addresses (URIs) and can show where identifiers are in use in the Web of Data. It can be used as underlying infrastructure to join related information using common locations, without the uncertainties associated with spatial matching.

1. www.csiro.au
Citing and understanding spatial references for eResearch:
Spatial Identifier Reference Framework (SIRF)
Paul Box, Terry Rankine, Rob Atkinson, Simon Cox
CSIRO
eResearch 2014 , Melbourne
DIGITAL PRODUCTIVITY FLAGSHIP

2. Understanding and citing spatial identifiers
• Spatial identifiers – nature and use
• Current challenges & future directions
• Spatial Identifiers Reference Framework - SIRF
Understanding and citing spatial references - SIRF | Paul Box2 |

3. Multi-disciplinary perspectives
Understanding and citing spatial references - SIRF | Paul Box3 |
The Critical Zone
Earth's permeable near-surface layer... from
the tops of the trees to the bottom of the
groundwater.
Hydrology, geology, soil science, biology, ecology, geochemistry, + anthropogenic.
Source: - US National Science Foundation
Critical Zone Observatory (CZO)
• Multiple domains, organizations, scientific
disciplines
• Information – multiple scales, sources, structure,
semantics, format & quality
• Different phenomena & reporting geographies
• Rapid information integration from multiple
sources
• Reliably link spatial + O&M
• Reliably link reporting geographies

4. The present - information silos
System
1
System
2
System
3
System
5
System
4
System
n
System
7
$
$
$$
$
$ $
Discover Access UnderstandExtract, Transform, Load
Use
Time and effort
Everything
Happens Somewhere
Understanding and citing spatial references - SIRF | Paul Box4 |
Gazetteer?

5. • Subjective constructs of geography - e.g. Gazetteer, local government areas,
catchment management authority area, ground water management unit
• Layer & feature based approach
• Identity (name, code)
• Type
• Geometry
• Topology
• Independent spatial layers + metadata in catalogues (SDI)
Representing location - spatial data
Concept
Relationship
Understanding and citing spatial references - SIRF | Paul Box5 |

6. Key issues
Dataset
• Identity is ambiguous
• Topology & geometry conflated
SDI
• Duplication - multiple representations
• Disconnection – spatial layers disconnected from:
• each other
• from other information
• Discovery - many catalogues, poor metadata @ dataset level
• Change
Understanding and citing spatial references - SIRF | Paul Box6 |

7. Identity
Understanding and citing spatial references - SIRF | Paul Box7 |

8. What’s in a name?
Official Country name lists
• United Nations Statistics Division Country and
Region Codes for Statistical Use
• United Nations Group of Experts on Geographic
Names - List of Country Names
• Department for General Assembly and Conference
Management - Multilingual Terminology Database
(UNTERM)
• ISO - ISO 3166: Codes for country names
• UN FAO - Global Administrative Unit Layers (GAUL)
Figure 1: Variation rates in spelling for country names
between the UN Statistical Division’s Country and Region
Codes for Statistical Use and UN datasets from data.un.org
• One place - many names
• Australia, Australie, ‫أستراليا‬
• Sydney, Syd, City of Sydney
• One name – many places
Understanding and citing spatial references - SIRF | Paul Box8 |

9. One name – many places
Understanding and citing spatial references - SIRF | Paul Box9 |
‘Leichhardt’
Leichhardt in Australia
4 (52) Australian Gazetteer (GA) - NSW, QLD
10 (12) ASGS (ABS) - NSW, VIC, QLD
Leichhardt in NSW
3 (9) in NSW Place Names search (GNB NSW)
Leichhardt (Sub) NSW
Feature types
• National Gazetteer
• Suburb
• Parish
• Homestead
•ASGS
• SA2 (NSW, QLD)
• SA3 (NSW)
• CED (QLD)
• IARE (NSW)
• State Suburb (VIC, NSW & QLD)
• Gazetted locality
•GNB
• County
• Parish
• Suburb (No LGA!)

10. One spatial object - multiple identities (& representations)
Geospatial information Other information resources
NSW Gaz (GNB NSW) 32679
Spatial Data Infrastructure (SDI)
Understanding and citing spatial references - SIRF | Paul Box10 |
Geonames 2160386
ASGS (ABS) SSC11351
Nat Gaz (GA) NSW3267

11. Identifiers in spatial data
• Ambiguous
• system scoped and non-unique
• multiple identifiers for same spatial object
• Unstable – not well managed change over time
• Not well governed
Understanding and citing spatial references - SIRF | Paul Box11 |

12. Geometry & topology
Understanding and citing spatial references - SIRF | Paul Box12 |

13. Separating geometry and topology
• Geometry used to encode topology
• Geometry used for visualization, analysis
• Most use cases need topology not geometry:
• Which Jurisdictions contains Leichhardt LGA
• Which rivers are upstream of the Hawkesbury?
• Geometry is – unreliable, inefficient for representing topology
Understanding and citing spatial references - SIRF | Paul Box13 |
LGA boundaries & State boundaries

14. What do we need?
• Unambiguously identify spatial objects using URIs
• Reliably cite geospatial features e.g.
• Geographic keywords
• Identify features used in workflow/model
• Cross-reference spatial identifiers to each other
• link multiple identities
• topology - touches, contains, adjacent
• Link spatial features to stats/obs
Understanding and citing spatial references - SIRF | Paul Box14 |

15. Spatial Identifier Reference
Framework - spatial linked
data enabling of SDI
Understanding and citing spatial references - SIRF | Paul Box15 |

16. Geospatial information Statistical information
(Implicitly geospatial)
GNB NSW 32679
Spatial Data Infrastructure (SDI)
Understanding and citing spatial references - SIRF | Paul Box16 |
Geonames 2160386
ABS ASGS SSC11351
GA Aus Gaz NSW3267
Linked spatial data to bridge existing gaps
Spatial
Identifier
Reference
Framework
Index Crosswalk Explore

17. How SIRF works – Indexing spatial references
SIRF
Spatial
Information
User
Linked
Data
Web
http://demo.sirf.net/siset/CGNA/NSW81093
http://demo.sirf.net/siset/AUS-FSDF/admin/2
Understanding and citing spatial references - SIRF | Paul Box17 |
(National) Spatial Data
Infrastructure
owl:sameAs

18. Understanding and citing spatial references - SIRF | Paul Box18 |

19. LinksetSISet SISet
Relationships between
spatial objects
Australian
National
Gazetteer
FSDF
Admin
Boundary
‘Cross-walks’ between SISets
• Centralise the problem
• Machine + manual processing
• Demand driven
• Cross-walks treated as first class citizens
• Well managed and shareable
19 | Understanding and citing spatial references - SIRF | Paul Box

20. http://id.sirf.net/siset/SA_SUBURBS/501001
- SA suburb
- SA gazetteer
- National gazetteer
SIRF data network
20 | Understanding and citing spatial references - SIRF | Paul Box

21. SIRF - linking between products
ANZ Foundation Spatial Data Framework
Understanding and citing spatial references - SIRF | Paul Box21 |
OWL SameAs
NSW
Albury
(LGA)
Towong
LGA
VIC
Geo:sf-adjacent
Geo:sf-contains
Geo:sf-contains
Geo:sf-adjacent
Geo:sf-contains
FSDF Admin Boundary Product
Leichhardt
(LGA)
S. Metro
Region
Albert Park
District
Geo:sf-contains
Geo:sf-contains
FSDF Place Name
Product
Geo:sf-contains
NSW
Geo:sf-contains
Leichhardt
Lambert
Park Geo:sf-contains
OWL SameAs
Cross-walks
registered in SIRF
Data set
indexed in SIRF
Data set
indexed in SIRF

22. Identifier patterns
Collection http://demo.sirf.net/siset/CGNA/
Instance http://demo.sirf.net/siset/CGNA/AHO34899 concept of Sydney
http://demo.sirf.net/siset/CGNA/AHO34899?_version=1.1.0 – representation of
the concept at a snapshot in time
Alt ID patterns
http://environment.data.gov.au/water/id/catchment/100862
Understanding and citing spatial references - SIRF | Paul Box22 |

23. Key messages
• Different to Wikipedia/Geonames
• NOT creating a new unauthoritative dataset
• Building set of indexes to underlying authoritative spatial data -
with provenance - source metadata
• Reliable unambiguous URI to reference to spatial object (concept
or representation)
• Linked data to express identity of and linkage between spatial
objects
• Bridge between native GIS representations and other data across
the web
• URIs – pattern and content governance
Understanding and citing spatial references - SIRF | Paul Box23 |

24. Paul Box
t: +61 2 93253122
e: paul.j.box@csiro.au
w: www.csiro.au
DIGITAL PRODUCTIVITY FLAGSHIP
Thank you
CSIRO Digital Productivity Flagship
SIRF OpenSearch http://unsdi.csiro.au/UNSDIOpenSearch/search
SIRF API doco http://www.sirf.net