Linked geodata: CityGML represented as a virtual knowledge graph
(2024) In Student thesis series INES NGEM01 20241Dept of Physical Geography and Ecosystem Science
- Abstract
- CityGML is an important standard to present 3D geometry, topology, semantics and appearance that together with 3D city models, which have had increased use within analysis and applications, such as emergency response, energy consumption and occupancy measurement. However, the standard’s querying and integration capabilities can still be further explored. One way to do this is through the Semantic Web technology knowledge graphs (KG). Proof-of-concept studies have been made using this approach but remains to be properly applied outside of studies as ad-hoc and data conversion approaches are still the most prevalent in practice. The approach can potentially be applied to fields such as the building permit process and transport infrastructure... (More)
- CityGML is an important standard to present 3D geometry, topology, semantics and appearance that together with 3D city models, which have had increased use within analysis and applications, such as emergency response, energy consumption and occupancy measurement. However, the standard’s querying and integration capabilities can still be further explored. One way to do this is through the Semantic Web technology knowledge graphs (KG). Proof-of-concept studies have been made using this approach but remains to be properly applied outside of studies as ad-hoc and data conversion approaches are still the most prevalent in practice. The approach can potentially be applied to fields such as the building permit process and transport infrastructure management as means to further help the digitalization in these fields and improve the workflows by allowing seamless linking and integration of other data while being queriable. This study provides a demonstration in how CityGML data can be presented as a virtual knowledge graph (VKG) in an effective manner through the commonly used tools 3DCityDB and Protégé with the Ontop plugin. This provides a means to improve interoperability between different types of data as well as a method to better manage semantical 3D city models. A framework is described in this study to populate the commonly used CityGML 2.0 ontology with CityGML data containing buildings from an area in Malmö, Sweden. This is primarily done through the use of R2RML mapping that retrieves the CityGML data from a 3DCityDB relational database to create virtual instances of data based on the CityGML ontology, thus exposing the data as a VKG through the Ontop system. To ensure that the data is effectively represented and demonstrated, SPARQL queries were performed to validate and test the KG. Seven queries were made in total to test different parts of the KG and to demonstrate some practical implications of the approach. The resulting KG constructed from the mapping retrieves the expected results through the queries, based on comparisons with the original data. As a result, it can be concluded that the CityGML data is effectively represented in the KG. Most notably, the showcasing of the mapping for LoD3 buildings provides a novel description of the implementation process. The framework described is sufficient for the representation despite the limitations imposed by the 3DCityDB database schema and Protégé suite while also demonstrating the potential use of the approach for urban planning processes. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9169387
- author
- Hansson, Felix LU
- supervisor
-
- Lars Harrie LU
- Rachid Oucheikh LU
- organization
- course
- NGEM01 20241
- year
- 2024
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Physical Geography and Ecosystem analysis, CityGML, geospatial knowledge graph, interoperability, data integration
- publication/series
- Student thesis series INES
- report number
- 672
- language
- English
- id
- 9169387
- date added to LUP
- 2024-06-28 16:14:23
- date last changed
- 2024-06-28 16:14:23
@misc{9169387,
abstract = {{CityGML is an important standard to present 3D geometry, topology, semantics and appearance that together with 3D city models, which have had increased use within analysis and applications, such as emergency response, energy consumption and occupancy measurement. However, the standard’s querying and integration capabilities can still be further explored. One way to do this is through the Semantic Web technology knowledge graphs (KG). Proof-of-concept studies have been made using this approach but remains to be properly applied outside of studies as ad-hoc and data conversion approaches are still the most prevalent in practice. The approach can potentially be applied to fields such as the building permit process and transport infrastructure management as means to further help the digitalization in these fields and improve the workflows by allowing seamless linking and integration of other data while being queriable. This study provides a demonstration in how CityGML data can be presented as a virtual knowledge graph (VKG) in an effective manner through the commonly used tools 3DCityDB and Protégé with the Ontop plugin. This provides a means to improve interoperability between different types of data as well as a method to better manage semantical 3D city models. A framework is described in this study to populate the commonly used CityGML 2.0 ontology with CityGML data containing buildings from an area in Malmö, Sweden. This is primarily done through the use of R2RML mapping that retrieves the CityGML data from a 3DCityDB relational database to create virtual instances of data based on the CityGML ontology, thus exposing the data as a VKG through the Ontop system. To ensure that the data is effectively represented and demonstrated, SPARQL queries were performed to validate and test the KG. Seven queries were made in total to test different parts of the KG and to demonstrate some practical implications of the approach. The resulting KG constructed from the mapping retrieves the expected results through the queries, based on comparisons with the original data. As a result, it can be concluded that the CityGML data is effectively represented in the KG. Most notably, the showcasing of the mapping for LoD3 buildings provides a novel description of the implementation process. The framework described is sufficient for the representation despite the limitations imposed by the 3DCityDB database schema and Protégé suite while also demonstrating the potential use of the approach for urban planning processes.}},
author = {{Hansson, Felix}},
language = {{eng}},
note = {{Student Paper}},
series = {{Student thesis series INES}},
title = {{Linked geodata: CityGML represented as a virtual knowledge graph}},
year = {{2024}},
}