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Data sharing: The first step towards a spatial data warehouse

Piet Nooij
Data Conversion Lead, AM/FM Project
BC Gas Utility Ltd.,1111 West Georgia Street
Vancouver, BC,Canada V6E 4M4
Telephone: (604) 443-6751
Fax: (604) 443-6599
email:pnooij@bcgas.com


Introduction
Government agencies, public utilities and other organisations, are becoming increasingly dependent on geographical and other information. Technology has also opened the door to opportunities to utilise this type of information for a multitude of uses and services that could not have been imagined even a few short years ago.

Historically, map data has been maintained in a variety of forms - most often on paper. Storage and maintenance of the information was complex and costly and each organisation kept their digital data in a variety of formats, making the exchange of information between organisations very difficult.

In 1995, when BC Gas initiated a paper to digital conversion of its large-scale facilities plate maps, accurate land base was needed to enable conversion of existing gas facilities information. BC Gas researched the availability of accurate land base and in several areas accurate data was available in either a CAD format or on paper. For BC Gas' purposes, accurate was defined as within 1 metre absolute accuracy. In rural areas, CDMS (Cadastral Data Management System) data, which is produced from 1:20,000 TRIM maps and has an accuracy of 5-10 metres, was available.

BC Gas successfully set-up agreements with the Provincial Government and most of the municipalities in its service area to share the cost of creating accurate digital land base by digitising existing plans or COGO survey plans. Additional data sets such as address information databases were imported to further enhance the base maps. As part of these agreements, BC Gas had to keep records of the owners of the source data to prevent copyright infringement problems when data had to be delivered to third party organisations. For each source, a meta-data record was created that identified the source's owner, data format, projection, datum, quality, and miscellaneous other information. It was and still is important to keep track of all sources, their accuracy's and to identify any changes in the land base data for future reference and to aid exchange. BC Gas' agreements required it to deliver the newly digitised land base and facilities back to each municipality to allow import into their own municipal GIS systems.

Another data sharing initiative in British Columbia is the PaRIS project, which is an acronym for Parcel Information System and was initiated by the Ministry of Environment Lands and Parks. PaRIS is a Geographical Information System used to store parcel, boundary, remediation sites, heritages sites and other attribute information. The project has successfully converted parcel information for several municipalities in British Columbia.

In Alberta, a Spatial Data Warehouse (SDW) initiative was created successfully in 1996 and was a joint venture of the major Alberta utility companies and the Alberta Government. The SDW has taken over the management (updating, storage and distribution) of the "Urban Cadastral" and "Rural Cadastral" as well as the topographic and small scale mapping data sets. The SDW has outsourced the maintenance and marketing of this information to the private sector.

The development of new digital technologies has made it possible to create, maintain and distribute digital data in many forms and formats. Distribution to users can be virtually instantaneous and based on up to date information.

Current Situation
Numerous public and private organisations require up-to-date information of mainly cadastral and topographical information to meet their day-to-day operational needs.

Local governments and public utilities require:
  • Up-to-date information on changes to parcel boundaries and land ownership;
  • Accurate street, address and parcel information
  • Location of utility infrastructure: hydro, gas, telephone, cable, water and sewer
  • Information on Crown tenures (leases, licenses, etc.)
Non-municipal and provincial agencies require similar information. Virtually all of the information required exists, however it is distributed among a number of different agencies and organisations.


Fig 1. Data Sets from the different organizations

Issues with the current situation
Distributed information is less than ideal and, as a result, those who require the information are faced with a number of issues:
  • There is no single source from which to access this information. This results in each organisation developing its own information system.
  • The information is not available in an integrated fashion. As a result an ad hoc manual integration is quite often carried out.
  • In some parts of the province the information is not available in a digital format.
  • Each organisation has its own standard or has multiple standards. There is no common mapping or data standard.
  • The information is in some parts of the province not up to date.
  • The spatial accuracy of the different data sets is not consistent. As a result the integrated data sets do not overlay.
  • Many sets of data contain redundant information.
The integrated cadastral initiative (ICI)
In late 1999, a steering committee was formed to explore the concept of an integrated solution to consolidate the various data sets from the Provincial Government, local governments and the public utilities. The partners in this initiative will each contribute specific data sets and regular updates to the 'warehouse'. Some of the partners will contribute information and data; others will provide in kind services and financing. The Steering Committee will provide overall direction for ICI. A Technical Committee was formed to research and analyse the technical implications of this 'warehouse'. Other technical committees will likely be formed in the near future to research and make recommendations for data transfer and communication between the different ICI partners.




Fig 2. The ICI Partners

ICI Objectives
The three major objectives of ICI are:
  1. "Achieving Cost Benefits from Economies of Scale: The one central information system should cost less than a larger number of small information systems maintained by each of the partners.
  2. "Enhancing the Data: All data for the approximately 1 million parcels will be converted from paper or from a digital format to an integrated province wide GIS database with attribute information. Data would also be integrated in layers, with partners in ICI getting access to specialised use data, such as Land Title Data, Assessment Data, zoning and utility infrastructure.
  3. "Improving Services: Along with the improvements to the data itself, there are potential improvements to the services offered with that data:


    • Improvements to data access: municipalities and provincial agencies may, as a result of ICI, be able to more quickly respond to request for information.
    • Improvements to associated services: partners may use ICI to improve their services; e.g. municipalities might be able to issue development permits more quickly.
ICI Organisational Issues:
There are several possible organizational structures that could be utilized or created to meet the organizational needs of the ICI. The organizational structure under consideration is a tripartite option involving the province, municipalities and the major utilities. Each brings various "assets" to ICI in the form of information or data, in kind services and financing.

There are two types of legal structure under consideration for ICI:
  1. A company incorporated under The Company Act:

    2. The advantage is limited liability and the ability to undertake a broad range of commercial activities. The disadvantages are that the share structure could be complex given the different organizational structures of the partners, in particular the "tiered" participation of the municipal and provincial agencies (i.e. UBCM and the individual municipalities; province and individual agencies). Individual municipalities and provincial agencies might also face difficulties in owning shares in a company. Tax issues will be complex and the perception that ICI perhaps competes with the private sector will have to be dealt with.

  2. A non-profit organization established under The Societies Act:

    3. Relatively uncomplicated to establish, limited liability applies, no major tax issues and there is less of a commercial perception problem. It is also easier for municipalities and provincial entities to become a member of a non-profit organization than shareholders of a for-profit entity. The disadvantages are that the organization cannot dispose of surpluses to its members and if the organization dissolves, assets cannot be liquidated and dispersed to its members, unless prescribed in bylaws.

    Given the balance of the advantages and disadvantages of each option, the Societies Act non-profit organization appears to be the preferred route for the establishment of the ICI.
ICI Layer Model
ICI will be the common repository for data sets from various organisations and will provide links to external data sets. The following layers of data are defined in ICI Layer Model:




Fig 3. The ICI Layer Model

Each ICI data set will be a subset of its original source database, a combination of different databases or link to an external data source. For example, the data set "Administrative Boundaries" contains data from different governmental agencies and municipalities; the "Gas" data set contains gas distribution mains and other major facilities such as stations and valves. The "Assessment Attributes" data set links to an external source.

The Technical Committee is in the process of defining the layer model to object and attribute level for each data set, defining which attribute is accessible for which party, e.g. a municipality can have access to land value a utility company cannot. The committee is also analysing data flow processes to address any new developments from the different agencies, municipalities and utility companies and will make recommendations to streamline the processes in ICI.

ICI Project Plan
The project business case initially spans over a period of 5 year. Each year will have associated activities and cost with it. The following high level tasks are defined:




Fig 4. ICI Project Plan

Year 1 is the pilot year and started in March 2000. Parcel and utility data sets have successfully been extracted and imported into a common GIS system at the Crown Land Registry Services, a department of the Ministry of Environment Lands and Parks. The major issues that have been addressed so far are:
  • "Facilities do not line up with the land base. The utility companies are using different or badly out-of-date land bases. Their data often does not have good accuracy because some might use less accurate methods to collect data or part of their data sets are still on paper. This is a major issue and has to be solved to enable the successful exchange of information between partners. Keeping track of meta-data for the land base and facilities is becoming more and more important.
  • "The land base or facilities data are not up to date. Turn around time has to be improved and it must become a priority to update land base and facilities in a timely matter.
  • "The various GIS systems of the ICI Partners have a different data structure. Each system defines object, attribute and topology such as point, line, area and annotation in their own way. A common data model is in the early stages of development and will address the object and attribute structure of the different systems. Tools have to be developed to extract data from the different GIS systems into this common data format.
Year 1 for ICI will end in March 2001 and the initiative will be evaluated on process, technical and cost issues. Year 2 will proceed based on the results of this evaluation process and will address the forming of the organisation and its legal structure, system developments and conversion and maintenance of the partner's data sets will continue.

Benefits

Benefits To Local Government
  • Municipalities will receive access to a consolidated digital cadastral map in a GIS structure which could include: legal boundaries, parcel identifiers, actual land use,administrative boundaries and other provincial data which might be beneficial to the business of the municipality.
  • The consolidated digital cadastral map will resolve any gaps or overlaps.
  • Frequent and regular updates of changes to ownership and other interests will be included.
  • A mechanism to resolve differences between various provincial and municipal data sets will be in place. Benefits To Utility Companies
  • Utility companies will have to go to only one organisation for a consolidated digital cadastral land base instead of acquiring data sets in various formats and accuracy's from multiple organisations (> 100 for BC Gas!).
  • The consolidated digital cadastral land base will be in a standard GIS structure, will have a consistent accuracy throughout the whole area and will frequently be updated.
  • For new developments, utility companies will use the same and always the most upto- date land base available. As a result more efficient exchange of proposed plans and alternatives will ensue.
  • Potential cost reduction for all partners through a single source for data assembly, integration and ongoing maintenance and distribution.
Conclusion
Sharing data via the ICI model, and using manual processes to import and export data sets between partners, will be a huge step forward in comparison to the "point-to-point" data sharing currently found between Government Agencies, utility companies and municipalities.

To create an ICI Data Warehouse with automated extracting and update processes is the ultimate long term vision for all of the ICI partners. This vision is still a long way away from reality, but it is perhaps, just a little closer to a reality than ever before.

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