1. Digital Census Mapping Process: United Nations Statistics Division
Expert Group Meeting on
Contemporary Practices in Census Mapping and Use of GIS
29 May -1 June 2007
New York
Digital Census Mapping Process:
a conceptual framework and different implementation approaches
United Nations Statistics Division

2. Summary Introduction-Mapping “Revolution”
Census Mapping Process: Conceptual Framework
Different Implementation Approaches
GIS, GPS, Digital Imagery: More integrated
Institutional/Organizational Issues
Critical Success Factors
Concluding remarks

3. Introduction Mapping “Revolution”: NSOs and Geospatial Technologies:
Shift: Manual to Digital
Paper map vs GIS map
Static vs interactive
User needs: increasing demand
NSOs and Geospatial Technologies:
Full advantage vs slow adoption
Real issue: integration for improvement

4. Census Cycle Pre-Census Census Post-Census (Pre-enumeration:
Maps provide cartographic basis for the delineation of EAs)
Census
(Enumeration:
Maps support data collection, monitoring)
Post-Census
(Post-enumeration:
Maps make it easier to analyze, display and disseminate)

5. Geographic Information Process (illustration)
Acquisition
Aerial Photography
Surveying.
Maps
Remote Sensing
GPS
Census & Surveys
Management/ Analysis
GeographicDataBase
GIS
Internet
Display/Dissemination

6. Census Mapping Process: conceptual framework
Census Mapping Operations: A Geographic Information Process
Different Mapping Needs at the three stages:
Pre-enumeration
Large-scale maps for delineation of EAs
Enumeration
Large-scale maps for enumeration
Mid-scale for monitoring
Post-enumeration
Mid and Small-scale maps for dissemination

7. Pre-enumeration stage
Pre-enumeration (EA Map Production)
Large-scale maps
EA units
Geocoding System
Census Database
Digital Mapping
GIS
Satellite Imagery
Aerial Photo.
GPS

8. Census Enumeration Stage
Pre-enumeration (EA Map Production)
Large-scale maps
EA units
Geocoding System
Census Database
Digital Mapping
GIS
Satellite Imagery
Aerial Photo.
GPS
Large-scale maps Large & mid-scale for sup.
Mid- & small-scale for manag.
Admin./Statistical Units
GPS
GIS
Digital Mapping
Enumeration (Census Data Collection)

9. Post-enumeration Stage
Mid- & small-scale maps
EA update
Statistical Database
Databases (Maintenance)
GIS
Internet Mapping
(Map Server)
Digital Mapping
Pre-enumeration (EA Map Production)
Large-scale maps
EA units
Geocoding System
Census Database
Digital Mapping
GIS
Satellite Imagery
Aerial Photo.
GPS
Large-scale maps Large & mid-scale for sup.
Mid- & small-scale for manag.
Admin./Statistical Units
GPS
GIS
Digital Mapping
Post-enumeration (Census Data Dissemination)
Enumeration (Census Data Collection)

10. Geospatial Technologies at all stages
Pre-census Census Post-Census
(Enumeration)
(Post-enumeration)
(Pre-enumeration)
Digital Mapping
Digital
Mapping
Statistical Database
Census Database
Databases
Maintenance
GIS
GIS
Aerial Photo.
GIS
Satellite Imagery
GPS
Internet Mapping
GPS
Administrative and Reporting Units
EAs Units

11. Different Implementation Approaches
Various combination of geospatial tools: depend on the approach chosen by NSO (needs vs resources)
Three main approaches:
Post-census
Full Census Program
Mixed Approach

12. Post-Census Approach Pre-census Census Post-Census (Enumeration)
(Post-enumeration)
(Pre-enumeration)
Digital Mapping
Databases
Maintenance
GIS
Internet Mapping
Administrative and Reporting Units

13. Post-Census Approach No extensive work under pressure
Need can be limited for maps with administrative and reporting units
Learning Process
Early planning exercise

14. Full Digital Census Mapping Program
Pre-census Census Post-Census
(Enumeration)
(Post-enumeration)
(Pre-enumeration)
Digital Mapping
Statistical
Database
Digital
Mapping
Census Database
Databases
Maintenance
GIS
GIS
Aerial Photo.
GIS
Satellite Imagery
GPS
Internet Mapping
GPS
Administrative and Reporting Units
EAs Units

15. Full Digital Census Mapping Program
Development of an EA Database
Rudimentary digital maps
Geo-referenced EA maps
Reference layers: roads, rivers, Landmarks, etc.
Digital Postal Address registry
Digital Database of dwelling units
Statistical Database
GIS and Internet-based Dissemination

16. Mixed Approach Pre-census Census Post-Census (Enumeration)
(Post-enumeration)
(Pre-enumeration)
Digital Mapping
Digital
Mapping
Statistical
Database
Census Database
Databases
Maintenance
GIS
GIS
Aerial Photo.
GIS
Satellite Imagery
GPS
Internet Mapping
GPS
Administrative and Reporting Units
EAs Units

17. Mixed Approach
Combination of existing maps + satellite imagery + aerial photos: up-to-date maps for major cities (or regions) for EAs + traditional techniques for other cities and rural areas
Geographic Database: Evolving Prototype

18. Recent Technological Developments
GPS: Greater accuracy, reduced cost, waypoints displayed real-time in a GIS software;
Satellite Imagery: Higher resolution, positional accuracy, and GIS-readiness;
Digital Arial Photo: extending its scope to small urban areas
Mobile GIS: Capture, manipulate, analyze and visualize data in the field in real time;
GIS+GPS+ Image Processing: Better integration.

19. Institutional/Organizational Issues
A specialized in-house Cartography/GIS unit
Building technical and human capacities
National Spatial Data Infrastructure (NSDI)
Basic data
Population Datasets and Geocoding System: basic components

20. Critical Factors
Ensuring Commitment for a long-term digital census mapping program;
Conducting a comprehensive needs assessment;
Tailor-made methodology of integration;
A Permanent unit for Cartography/GIS within the NSO;
Partnership and cooperation;
Capacity Building for sustaining the census mapping program.

21. Concluding Remarks
For 2010 the P&R recommended the use of Geospatial technologies for improving traditional methods of census mapping
Digital Census Mapping Process: spanning all the stages of census data collection, analysis and dissemination
Implementation Approach: each country has to find its own best possible solution
Best Practices - Revision and Update of the Handbook on GIS and Digital Mapping

22. Thought of the day:
GIS, GPS and Remote Sensing bring sense to censuses!