Towards a Web application for viewing Spatial Linked Open Data of Rotterdam

Transcription

1 Towards a Web application for viewing Spatial Linked Open Data of Rotterdam Godelief Abhilakh Missier Msc Geomatics for the Built Environment P5 presentation Challenge the future 1

2 Content 1. Introduction 2. Research 3. Conclusions 2

3 Open Data Data that is freely available on the Web Transparent Stimulate innovation 3

4 Data.overheid.nl 4

5 PDOK.nl 5

6 5 star scheme Developed by Tim Berners-Lee 6

7 5 star scheme 7

8 Linked Data 8

9 Example 9

10 More information 10

11 Combine datasets 11

12 Semantic Web 12

13 Difficult Know the content of the dataset Metadata/semantics Combine datasets Knowledge of Geo data formats 13

14 Linked Data and Spatial Data Provide more content to users Aiding location based services Combining spatial data with other datasets Ask questions over data on the Web: SPARQL 14

15 GeoSPARQL ontology OGC standard Model the geometry and topology Ask spatial queries 15

16 RelatedWork More and more research in (spatial) linked data Linked Data Web application by Geonovum from 16

17 Objectives To research how to model the spatial data (5 star) according to the linked data method, in order to benefit from the advantages Propose a methodology Using existing standards and tools 17

18 Research question Interest by the Municipality of Rotterdam What are possibilities and limitations of the use of spatial Linked Open Data for the Municipality of Rotterdam? 18

19 Sub questions 1. How to publish spatial data as Linked Data on the Web? 2. What are options for linking spatial datasets? 3. How to query distributed and heterogeneous spatial datasets? 4. How to create a Web application with spatial Linked Data? 19

20 Case study Rotterdam Zuid 20

21 Rotterdam Open Data Store Open data portal of Rotterdam Dataset about kindergartens (shp) 21

22 Rotterdam in Cijfers Research and Intelligence department "","0 kinderen","1 kind","2 kinderen","3 kinderen","4 kinderen","5 of meer kinderen" "Feijenoord","23462","5699","3847","1574","488","162 "IJsselmonde","19631","4688","3208","1102","289","113" "Charlois","23969","4999","3260","1135","323","126" "Pernis","1426","391","304","72","15","1" Dataset of number of children per household (csv) 22

23 CBS Statistics Netherlands Area and neighbourhood map demographic statistical data (shp) 23

24 BAG Base registration of addresses and buildings Premises, addresses and residential units (tables) 24

25 Methodology 25

26 Creating Spatial Linked Open Data

27 Model for the BAG Mapping schema 27

28 BAG as Spatial Linked Open Data Function Address + Geometry Geometry Construction year Area Residential unit Premise Linked Data visualized in Gruff 28

29 RDF storage approach Approach 1 Tables in database Python psycopg2 RDFLib Import RDF file Strabon Publish to the Web Pubby Copy 29

30 On-the-fly to RDF approach Approach 2 Tables in database D2RQ Platform Published to the Web Virtual copy 30

31 Visualization RDF GeoJSON 31

32 Example

33 Layman users Spatial linked open data: Accessing Understanding Finding additional information 33

34 A scenario Suppose the municipality wants to do a study on the number of kindergartens in Rotterdam Zuid 34

35 How many kindergartens are in which areas in Rotterdam Zuid? SELECT?wijk (COUNT(?kinderdagverblijf) AS?amount) WHERE{?kinderdagverblijf a < geo:hasgeometry?geo.?geo geo:aswkt?wkt.?wijk a < geo:hasgeometry?wgeo.?wgeo geo:aswkt?wwkt. FILTER(geof:sfContains(?wwkt,?wkt)).} GROUP BY?wijk Spatial Query 35

36 How many kindergartens are in which areas in Rotterdam Zuid? Spatial join 36

37 Federated query How is the composition of Pernis? PREFIX dbpedia: < SELECT DISTINCT?comment WHERE { SERVICE < { dbpedia:pernis?p?o. dbpedia:pernis rdfs:comment?comment. }} Web of Data 37

38 How far is the nearest kindergarten from Pernis? Nearest neighbor 38

39 Expert users Analysis over distributed and heterogeneous spatial datasets on the Web 39

40 Linking datasets Explicit linking Rotterdam in Cijfers CBS gebied:feijenoord owl:sameas wijk:feijenoord gebied:charlois owl:sameas wijk:charlois gebied:haven-enindustriegebieden owl:sameas wijk:vondelingenplaat gebied:haven-enindustriegebieden owl:sameas, wijk:waalhaven Creating explicit triples 40

41 Linking datasets Dynamic linking < wijk:wk_code WK < buurt:wk_code WK Linking on foreign key 41

42 Linking datasets Dynamic linking Linking on topology in query 42

43 Conclusions & Recommendations

44 Conclusions Possibilities Layman and expert users benefit Analyze cross knowledge domain issues Urban planning Emergency management Sustainable design 44

45 Conclusions Limitations Not complete support in tools for spatial data/geosparql Time consuming to prepare the data/customize the triples 45

46 Future work Other software/tools Scalability 46

47 Reflection A Municipality has many applications for spatial linked (open) data Linked data cannot be achieved alone 47

48 Questions? Thanks for the attention!