INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
United Nations Expert Group Meeting on Contemporary
Practices in Census Mapping and Use of Geographical
Information System
Census 2011 Portuguese Mapping Process
ana.msantos@ine.pt
29 May – 1 June 2007, New York
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
PORTUGAL
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
AGENDA
1. Census Maps (1981 - 1991 – 2001)
2. National Territorial Divisions
 Administrative
 Statistical
3. Digital Census Mapping Program
 Activities carried out during the period 1997/2001
4. The 2007 Technological Infra-structure
5. 2011 Census Maps
6. Final Notes
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
1. CENSUS MAPS
► For the 1981 Census:
►cartography as a means of support for data collection
►major cities
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
1. CENSUS MAPS
► For the 1991 Census:
►A full geographical basis of the whole Portuguese territory
►“Geographic Spatial Referencing Basis” (BGRE 1991)
– analogical format –
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
1. CENSUS MAPS
► In 1995 – Beginning of the work on the cartographic infra-structure to
support the 2001 Census
► “Geographic Information Referencing Basis” (BGRI 2001)
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
2. NATIONAL TERRITORIAL DIVISION
NATIONAL ADMINISTRATIVE DIVISION
► DISTRICTS - 18
AUTONOMOUS REGIONS – 2
► MUNICIPALITIES – 308
► PARISHES - 4260
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
2. NATIONAL TERRITORIAL DIVISION
NATIONAL STATISTICAL DIVISION – BGRI 2001
Each basic administrative unit, the “Parish”, is subdivided into smaller
statistical areas – statistical sections and subsections
► STATISTICAL SECTIONS – 16 094
Territorial unit representing the continuous area of a single Parish with
approximately 300 dwellings
► STATISTICAL SUBSECTIONS – 177 893
Territorial unit which identifies the smallest homogeneous area, whether
built-up or not, existing within the statistical section. It represents a block in
urban areas, a locality or part of a locality in rural areas
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
2. NATIONAL TERRITORIAL DIVISION
NATIONAL STATISTICAL DIVISION
EXAMPLE: District of FARO
subdivided into 15 Municipalities
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
2. NATIONAL TERRITORIAL DIVISION
NATIONAL STATISTICAL DIVISION
EXAMPLE: Municipality of FARO
subdivided into 6 Parishes
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
2. NACIONAL TERRITORIAL DIVISION
NACIONAL STATISTICAL DIVISION
EXAMPLE: Statistical Section
subdivide into 18 statistical
subsections
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
3. DIGITAL CENSUS MAPPING PROGRAM
1997/2001 – Implementing a full digital Census mapping program
 Main Decisions and Tasks:
SETTING UP A GIS UNIT WITHIN THE NATIONAL STATISTICAL
OFFICE in a regional structure
 Acquiring the specific skills (new staff members, continuous
training)
 Acquiring GIS technologies
 Providing access to geographic data
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
3. DIGITAL CENSUS MAPPING PROGRAM
 Main Decisions and Tasks:
COOPERATION STRATEGY
Partnerships between:
 The Portuguese National Statistical Institute
 Major institutional producers or users of geographic data:




National Mapping Agency
Portuguese Postal Services
Army Geographical Institute
Municipal Associations and Municipalities
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
3. DIGITAL CENSUS MAPPING PROGRAM
 Main Decisions and Tasks:
BUILDING STAGES
- Updating the 1991 census mapping - BGRE 1991
This process was carried out following different stages:
 Building the digital version of analogical BGRE 1991 (performed by the Army
Geographical Institute)
 Editing the BGRE 1991 - preliminary BGRI 2001 – (performed by National
Statistical Institute and very few Municipalities)
 Data validation (performed by the Municipalities)
All the following information was verified and ratified:
• the administrative boundaries of each Parish
• the identification of localities (place, names and perimeters)
• the model of statistical division proposed
 Printing process (performed by the Army Geographical Institute)
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
3. DIGITAL CENSUS MAPPING PROGRAM
 Main Decisions and Tasks:
MAJOR PROBLEMS





Inexistence of updated and standard geographical reference data for the
whole country
Different versions of administrative boundaries – Municipalities (NUTS 4) and
Parishes (NUTS 5) – and difficulties in defining both the name of localities and
boundaries
Inexistence of updated data about the number of dwellings in each statistical
section, for the purpose of size definition
The large dimension of the editing process and maps plotting
The difficulty in importing and checking the quality of local edited data, when
the municipalities had assumed the responsibility to create the BGRI 2001
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
4. THE 2007 TECHNOLOGICAL INFRA-STRUCTURE
DATA INFRA-STRUCTURE (GEODATABASE)
 The geographical information :
- stored in a centralized Database of images and vectorial data
- divided into 6 logical groups:






Reference Data
Administrative Units
NUTS Units
Census Units
Streets
Buildings
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
4. THE 2007 TECHNOLOGICAL INFRA-STRUCTURE
 features of the NSI
spatial data infra-structure
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
4. THE 2007 TECHNOLOGICAL INFRA-STRUCTURE
ESRI SOFTWARE
The NSI has acquired, since 1997, ESRI software products
ERDAS
ArcView3
ArcGis9
Desktop
Server
Data
ArcGis
Server
ArcSDE
ArcIMS
Files
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
DBMS
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
GOALS
 The essential target of the preparation of census cartography for
the 2011 Census (BGRI 2011) can be established according to
the following :

to update in an exhaustive way the
geographical/administrative and statistical boundaries

to update the contents of statistical sections (enumeration
districts), related to the number of dwellings
This set of goals ensures the production of a mapping support
identical to the one used during the 2001 Census
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
GOALS
 Data infra-structure improvements
- regarding the quality of the streets logical group database with:
street names
building numbers
from sources already available:
 municipalities
 commercial firms of street networks
 Advantages to the Census operation:
the identification of the majority of addresses visited by the enumerators
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
GOALS
 Apart from this, a street network providing addresses
would allow :
a comparative analysis of all files used at NSI
(as long as they contain an address)
the beginning of an infra-structure of greater flexibility in the creation
of sample bases
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
STRATEGY
 NSI should privilege a cooperation strategy with official
organizations producing or owning geographical information:
 National Mapping Agency
 Municipal Associations and Municipalities
for:


the acquisition of updated reference cartography of large scale
the updating of the Geographical Reference Infrastructure
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
METHODOLOGIES
 Key procedures adopted by NSI to create the 2011 Census map:
 The use of official administrative boundaries
 The use of large scale orthophotomaps to perform the editing process
 Choosing ArcGis Server to develop a web application to support the
editing process
 Conducting an assessment of the possibility of using external
commercial or municipality data to build a network street file
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
METHODOLOGIES

In spite of :
the need to do the editing and classification work, related to the:
 Existence of geometrically wrongly positioned arcs
 Out of date data (digitalization of new arcs)
 Inexistence or deficient classification of arcs with attribute addresses
►The technical use of commercial data, as nuclear data for the
updating of the geographical reference infra-structure is possible
 it enables NSI to minimize the effort of digitalization of new arcs and
polygons, and increase the availability of address attributes
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
New
Administrative
Boundaries
Editing
Data Set
Reference Data
Reference Data
Rules
 BGRI 2011 building
stages:
Streets Network
Editing
Other Editing
Structuring
Elements
Funcionalities
Polygon Creation
Process
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
BGRI 2011
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
DIFFICULTIES
in classifying the statistical subsections of the 2011 BGRI:
 The Codification System in 1991 BGRE and 2001 BGRI uses a
numerical sequenciality but does not allow the use of the same code when
changes occur to the boundaries of statistical subsections or sections
 Because:
 the identification system offers two digits while numbering the subsection
within the section
 the definition of a considerable number of new statistical subsections is
expected
 This codification system is no longer valid
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
DIFFICULTIES
 MAINTENANCE OF HISTORY:  Census 1991 / Census 2001
 made possible by the creation of a Minimum Common Base (BMC)
1991 BGRE
2001 BGRI
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
BMC
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
PROBLEMS /DIFFICULTIES
 MAINTENANCE OF HISTORY:
 Census 1991 / Census 2001/ Census 2011
 Having a codification system no longer valid and
 an enlarged dimension of the expected Minimum Common Base
 the maintenance of history will be guaranteed by the georeference of building Census 2011
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
FINAL NOTES
 The existing infra-structure of a strictly polygon nature
concerning small statistical areas is used for data collection
and data dissemination
This hierarchy level enables the user to define any superior level
 This infra-structure is the starting point in the creation of 2011 census
maps, a process started by NSI in 2006
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
5. 2011 CENSUS MAPS
FINAL NOTES
 In order to develop the spatial data infra-structure, NSI decided to
assess the costs/benefits of implementing a new component (a street
network providing addresses) to perform a new set of activities
(apart from Census 2011):





the definition of a new 2011 Master Sample
the use of administrative files
the increasing geocoding of statistical unit files
the increasing dissemination of geographical data
the preparation of the spatial data infra-structure to enable the transition
to a new census model in 2021
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York
INSTITUTO NACIONAL DE ESTATÍSTICA
Census 2011 Mapping Portuguese Process
THANK YOU FOR YOUR ATTENTION
ana.msantos@ine.pt
INSTITUTO NACIONAL DE ESTATÍSTICA
PORTUGAL
United Nations EGM on Contemporary Practices in Census Mapping and Use of GIS
29 May – 1 June 2007, New York