At the the Year in Infrastructure conference in London the Singapore Land Authority (SLA) won the annual Be Inspired Award for Innovation in Government. Comprising only 700 square kilometers for the entire nation, land is a valuable and critical national resource for Singapore and the Singapore Land Authority is responsible for making the most of the resource.
Specifically SLA is responsible for the national land management system and for all geographical information (GIS) management. At the Be Inspired Awards at the Year in Infrastructure 2015 conference in London, I had an opportunity to chat with Victor Khoo and Kean Huat Soon. Victor Khoo is Deputy Director Land Survey at the SLA and Kean Huat Soon is a Senior Surveyor and the technical lead for the project.
Singapore intends to be the world's first "smart nation". Part of this initiative involves developing a virtual Singapore that is intended to be the source of authoritative information about Singapore for use by government. The current priority is a 3D model of buildings and below and above ground infrastructure.
The Mapping Singapore in 3D project is financed 50% by the Government of Singapore and 50% by agencies, primarily the Civil Aviation Authority of Singapore (CAAS) and the Public Utilities Board (PUB). Several government agencies including the Building and Construction Authority (BCA) and the Housing Development Board (HDB) are already using it. CAAS finds it essential for maintaining aviation glide paths over the city as does the PUB for assessing the impact of flooding. HDB uses it for planning purposes.
The project involves capturing large amounts of data using multiple rapid mapping technologies including oblique imagery, airborne laser scanning, mobile laser scanning, and terrestrial scanning. The data is compiled into 3D city model in a single database repository. The database includes geometry, topology, semantics and appearance. It relies on CityGML, a standard managed by the Open Geospatial Consortium (OGC), for the database schema and for data exchange. The project works at the Level of Detail (LOD) Level 1-3. The data is stored in a single geospatially-enabled relational database (Oracle Spatial). The total volume of data is more than 50 terabytes.The most challenging part of the project has been the development of business processes and technologies for ensuring the data remains current. The database is open and accessible to all government agencies.
Victor Khoo is also responsible for developing a 3D cadastre for Singapore which is a separate project at SLA. A 3D cadastre is especially critical for Singapore for several reasons. 85 % of the population of Singapore lives in public high rise buildings. Underground space is heavily used and underground density is increasing. Land developers are being very creative and packaging complex volumetric parcels that include both underground and above ground.
A 3D cadastre has data, legal, system and process dimensions. The legislation required for the legal aspect is already in place. The system and processes are intended to be completed by the end of 2016. With respect to data a 3D GIS is being populated at SLA starting with 2D land parcel data.
Land surveyors are an essential part of the 3D cadastre project. As a first step surveyors are required to use electronic data exchange instead of paper (Singapore mandated electronic submissions for building permitting over a decade ago.) Singapore has decided to support ePlan LandXML as an open standard for the exchange of survey data. In 2013 Singapore joined the ePlan working group which is focussed on developing a digital protocol for the transfer of cadastral data between the surveying Industry and government. The working group was originally made up of technical experts from the eight states and territories of Australia and New Zealand working in the management of cadastral data.
By way of background LandXML is a widely used standard used by the transportation and land development sectors. A subset of the LandXML standard including alignment, road, rail, survey, terrain, land parcels, drainage, wastewater, and water distribution systems is being incorporated in a new standard called InfraGML which is supported by the OGC. Its focus is alignments/roads, survey, and land parcels and it synchronizes with the concurrent efforts by buildingSMART International in its development of infrastructure-based Industry Foundation Classes (IFCs), for example, for alignments, as well as with CityGML and TransXML. The first public draft of the OGC's proposed UML conceptual model for land parcels and the built environment was released for public comment at the beginning of the year.
BIM IFC and CityGML
An outstanding issue is the integration of BIM models into the Singapore city model. A number of groups are working on a way of integrating CityGML and the BIM Industry Foundation Classes (IFC) standard. An example is the Dutch 3D standard.
Energy modeling for cities
The European SUNSHINE (Smart Urban Services for Higher Energy Efficiency) project has found a data model within the INSPIRE standard that is adequate for energy performance modeling for cities. CityGML has strongly influenced the development of the INSPIRE BU model, both for 2D and for 3D profiles. Many use cases that were considered for INSPIRE BU require a three-dimensional representation of buildings such as a building information model (BIM). Examples are noise emission simulation and mapping, solar radiation computation or the design of an infrastructure project. To allow for that, the building representation in Level of Detail (LoD1 - LoD4) of CityGML has been added to the INSPIRE BU model as a core 3D profile. For large scale energy performance at the urban level, the SUNSHINE team concluded that detailed interior elements of each building are not required. It is possible to work at a simple Level of Detail 3 (LOD3) and just include elements like roofs, envelope walls, and windows.