CORPORATE SPATIAL DATABASE
DEPARTMENT OF WATER AFFAIRS
|VERSION NO: 1.00|
|VERSION DATE: January 1998|
|DOC TYPE: POLICY FOR CORPORATE SPATIAL DATABASE|
TABLE OF CONTENT
1. ACRONYMS AND DEFINITIONS *
1.1 ACRONYMS *
1.2 DEFINITIONS *
2. THE VALUE OF A GIS CO-ORDINATION POLICY *
3. GUIDELINES FOR A CORPORATE SPATIAL DATABASE *
3.1 STANDARDISATION OF GIS PRODUCTS *
3.2 THE ROLE OF INFOSERVICES IN ESTABLISHING A CORPORATE SPATIAL DATABASE *
3.3 THE ROLE OF Business Information IN ESTABLISHING A CORPORATE SPATIAL DATABASE *
3.4 DATA STANDARDS *
3.5 DATA CAPTURED FOR THE CORPORATE SPATIAL DATABASE *
3.6 TENDERS *
3.7 CARTOGRAPHY SERVICE FOR THE CORPORATE SPATIAL DATABASE *
3.8 INCORPORATING SPATIAL DATA FROM EXISTING GIS SYSTEMS INTO THE CORPORATE DATABASE *
3.9 DISTRIBUTION OF GIS DATA *
3.10 DATA ERROR RECORDING AND ANALYSIS *
3.11 REGIONAL OFFICES *
4. WORKFLOW PROCESSES FOR CORPORATE GIS PROJECTS *
TABLE OF FIGURES
Figure 1: Simplified Workflow for GIS Projects *
Figure 2: Directorate Business Information *
1. ACRONYMS AND DEFINITIONS
DWAF Department of Water Affairs and Forestry
GIS Geographic Information System
LAN Local Area Network
RDBMS Relational Database Management System
SDE Spatial Database Engine
Corporate data All data that is, or may be, used by more than one component of DWAF.
Corporate data base A platform/base on which data is consistent, compatible and accessible to any authorised person. A corporate database may be centralised, or distributed and integrated.
Corporate GIS Project A GIS project that collects or produces data sets for the corporate database.
Custodian of data A person responsible for maintaining a data set and the integrity of the data.
Database design Analysis and determination of table structures for storing data in the database.
Data Integrity The soundness of data, based on completeness and accuracy.
Directorate: Business Information Previously the Directorate: Survey Services, renamed to reflect a move towards digital techniques and embodying a new GIS Data Management sub-directorate and related functions.
GIS Data Management Handling of spatial data according to accepted systems with specified rules and requirements.
Spatial Data Spatial data includes all geo-referenced data and associated attribute data.
Time and Material Time and material expended to serve an employer. In a Time and Material based contract, a preset amount is payable per unit of delivery. The total contract value is the cost of all the quantities needed to complete the work.
2. THE VALUE OF A GIS CO-ORDINATION POLICY
As several DWAF directorates, or consultants employed by them, have developed unique GIS applications or undertaken studies without agreed standards using different software packages, the usefulness of each set of spatially related information is generally limited to a specific directorate. This implies that resources are wasted if the same information is captured repeatedly, while the risk is high that the same data captured independently will not be compatible or readily available to others.
To eliminate inefficiencies, a Corporate GIS to provide information to everyone is being established using the DWAFs Informix Relational Database Management System (RDBMS) (an integrated platform of databases). GIS users will be able to access data and relevant facilities for manipulating it via the DWAFs LAN or Intranet, using packages such as ArcView, MapObjects, Map Publisher and others.
For this purpose the Directorate: Information Services (Infoservices) will use ESRIs Spatial Database Engine (SDE) for quick and easy distribution of corporate data to users, including eventual online access by the regional offices. For the data maintained by many directorates for their own purposes to be widely usable, it is necessary that the Directorate: Business Information (Business Information) ensures that it is captured to a consistent standard in a suitable format. As a control measure, ESRIs ArcStorm will be used to validate and manage spatial data before it is deposited in the SDE database. Although the design of the database and storage standards for spatial and attribute data are the responsibility of Infoservices, Business Information is responsible for maintaining the DWAFs spatial and meta-databases and the custodians of the data in individual directorates are responsible for the integrity of their data.
Achieving this vision requires a set of guidelines.
3. GUIDELINES FOR A CORPORATE SPATIAL DATABASE
3.1 STANDARDISATION OF GIS PRODUCTS
1. The corporate spatial database is founded on an Informix database in association with ESRIs SDE and ARC related products.
3.2 THE ROLE OF INFOSERVICES IN ESTABLISHING A CORPORATE SPATIAL DATABASE
1. Infoservices is responsible for designing, maintaining, servicing and securing the corporate spatial database, as well as for developing requested applications and for providing a technical means of distribution of the data to users. These functions include the provision of standards and quality assurance for all system development.
2. Before capturing spatial data the design requirements for attribute data associated with it must be ascertained from Infoservices to ensure that the digital product meets the corporate database requirements.
3.3 THE ROLE OF Business Information IN ESTABLISHING A CORPORATE SPATIAL DATABASE
1. Business Information is responsible for the actual management of GIS Data. This entails the following tasks:
Setting GIS data standards;
Performing quality assurance checks on corporate data;
Populating the corporate spatial database;
Co-ordinating data capturing activities within and on behalf of the DWAF and its regional offices;
Setting policy for controlling and distributing spatial data;
Distributing spatial data via mechanisms provided by Infoservices; and
Providing a cartography service.
A schematic layout of the Directorate: Business Information is given in Figure 2.
3.4 DATA STANDARDS
1. Infoservices is responsible for the development of data storage standards and specialised software.
2. Business Information is responsible for the establishment of spatial data standards.
3. The data-capture standards for spatial and attribute data which are available from Business Information and Infoservices, must be observed when capturing spatial data.
3.5 DATA CAPTURED FOR THE CORPORATE SPATIAL DATABASE
1. The custodian of the data in each directorate is responsible for the integrity of the data.
2. The standards and format of the spatial data and its attributes captured for the corporate database must be verified by Business Information Spatial Data Management Division of its Sub-Directorate: GIS Data Management, which will also ensure that the attributes are linked to the coverages before making the data available in the corporate database.
3. Business Information Sub-Directorate: GIS Data Management co-ordinates DWAFs data capture activities and keeps track of whatever data is being captured where and by whom. As a feature of the corporate database, the Sub-Directorate will maintain a meta-database of spatial data being captured in the department, of data available in the corporate database, and of the whereabouts of data available from outside organisations.
4. The Sub-Directorate: GIS Data Managements division for spatial data capture must be involved in the capture of any data for the corporate database. It is also responsible for distributing spatial data to regional offices until they are directly on-line.
5. The meta-database will be made to comply with international standards, once these are agreed.
6. As it is vital that the data captured for the corporate GIS satisfies users requirements, a GIS Users Group, chaired by Business Information, has been established to determine the needs.
Business Information is responsible for maintaining standards for evaluating DWAF tender documents for spatial data capture. Each tender document, which must be evaluated by Business Information before being advertised, must prescribe data capture standards and have penalty and guarantee clauses.
Business Information is responsible for determining standard terms of payment for data capture. Contractors will not invariably be paid on a "time and material" basis.
Business Information must verify recommendations for awarding tenders which are adjudicated by the requesting body.
Infoservices is responsible for providing system development standards as well as for system development quality assurance for any aspect of a project.
3.7 CARTOGRAPHY SERVICE FOR THE CORPORATE SPATIAL DATABASE
1. Business Information Sub-Directorate: GIS Data Management has a division which undertakes cartographic tasks using corporate spatial data. This includes setting and maintaining cartographic standards and advising on cartographic conventions.
3.8 INCORPORATING SPATIAL DATA FROM EXISTING GIS SYSTEMS INTO THE CORPORATE DATABASE
1. Business Information Spatial Data Co-ordination Division of the Sub-Directorate: GIS Data Management can convert the data and data-access procedures (where practicable) of existing GIS systems (eg WQIMS and CompMan) or external GIS systems (eg REGIS) to a format suitable for the corporate database. A set of standards will be maintained for this purpose.
3.9 DISTRIBUTION OF GIS DATA
1. Infoservices is responsible for providing the SDE and other mechanisms to distribute spatial data in the corporate database, as well as developed applications, enabling users to use tools such as ArcView, ArcExplorer and Mapobjects.
2. Business Information is responsible for developing a copyright and data distribution policy, within and external to DWAF.
3.10 DATA ERROR RECORDING AND ANALYSIS
Business Information is responsible for recording and analysing data errors, and for taking corrective action.
3.11 REGIONAL OFFICES
Business Information will provide data to regional offices on request where possible and will co-ordinate data capture tenders for regional offices.
Data captured by regional offices must meet the standards prescribed in the documentation available from Business Information.
3. Regional offices must notify Business Information of any modifications to data sets and provide it with updates (and vice versa). Databases at regional offices must be developed in parallel with the corporate database.
4. WORKFLOW PROCESSES FOR CORPORATE GIS PROJECTS
A simplified workflow process for all GIS projects is shown in Fig. 1.
1. All requests for corporate GIS projects must be directed to Business Information, whereafter a Joint Project Meeting (JPM) will be held to determine the viability of the project, the deliverables and the data requirements. The JPM is to be attended by representatives of Infoservices, Business Information and the client. A project manager will be appointed to oversee viable projects.
2. If there is no provision for the attribute data associated with the spatial data in the corporate database, Infoservices must provide a suitable design to accommodate it.
3. If the required GIS data sets or coverages are available in the corporate database, application developers may proceed directly with data analysis and application development.
4. If GIS datasets or coverages are not available in the corporate database, Business Information must determine whether they are available from other sources, and if not, co-ordinate their capture.
5. Spatial data which is captured for a particular purpose or is obtained elsewhere must be verified by Business Information before it is added to the corporate database.
6. Once any necessary data analysis and application development is done, Business Information automated Cartographic Division can assist with graphic visualisation.
Once the completed work has been made available to the client using appropriate technology, all maps and automated mapping routines will be catalogued and kept by Business Information.
SIMPLIFIED WORKFLOW FOR GIS PROJECTS
Figure 1: Simplified Workflow for GIS Projects
A SCHEMATIC LAYOUT OF THE DIRECTORATE Business Information
Figure 2: Directorate Business Information
VERSION PAGE STATUS
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09 July 1997
05 August 1997
08 October 1997
29 December 1997
07 January 1998
S van Niekerk
A Cochlovius Gouws
C de Jong
J de Klerk
F de Kock
A Cochlovius Gouws
J de Klerk
C de Jong
A Cochlovius Gouws
A Cochlovius Gouws
J de Klerk
This document is available from:
The Directors of Business Information and Information Services
Department of Water Affairs & Forestry
An electronic version (MSWord 6.0 format) of this document is available under document title: GISPOL.WORD6
DIRECTOR: Business Information DIRECTOR: INFORMATION SERVICES
CHIEF DIRECTOR: SCIENTIFIC SERVICES CHIEF DIRECTOR: PLANNING
DEPUTY DIRECTOR GENERAL: DEPUTY DIRECTOR GENERAL:
WATER UTILISATION PLANNING