United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Building a Geographic Database and Using GIS and Spatial Analysis for Census Data Dissemination UN Statistics Division

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Outline UN Recommendations/Census Geography Programme Building a Geographic Database Spatial Analysis Techniques SALB Project Handbook on Geospatial Infrastructure in Support of Census Activities

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Census Geography Programme: a continuous process  The recommendations derived from UN EGM and Workshops on GIS and census mapping emphasized the need for countries to consider the census geography programme as a continuous process, rather than the sequential mapping and dissemination operations.  It was also emphasized that the use of and application of contemporary geospatial technologies and geographical databases is beneficial at all stages of population and housing census process. Geospatial improve the efficiency in the preparatory, enumeration, processing and dissemination phases of the census

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Census Cycle

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Geospatial tools at all stages EAs Units Administrative and Reporting Units GPS Photo/Video GIS Digital Mapping Satellite Imagery Pre-census Census Post-Census GPS/PDA GIS Digital Mapping GIS Internet ( Map-Server ) (Pre-enumeration)(Enumeration)(Post-enumeration)

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Admininstration Hierarchy  Every country has its own specific administrative hierarchy  Definition: A system by which the country and each lower level set of administrative units (except the lowest) are subdivided to form the next lower level.  Administrative areas for which census data will be reported

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Coding Scheme  EA: a basic geographic feature  Need for an identifier: linking the geographic feature to the census data (attributes) recorded for them  EAs and administrative units: coding scheme A unique code assigned to each EA, used in data processing Coding scheme: scalability, flexibility, intuitiveness, compatibility  Example of a hierarchical coding scheme province districtlocality Enumeration area

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Geocoding Concept  “Geocoding can be broadly defined as the assignment of a code to a geographic location. Usually however, Geocoding refers to a more specific assignment of geographic coordinates (latitude, longitude) to an individual address ( UN Report of the EGM on Contemporary Practices in Census Mapping and Use of GIS, 2007 )  Geo-coding: not limited to address-matching  Geocoding covers a continuum of spatial scales: from individual housing units to enumeration area level up to higher administrative or national levels.

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Implementation of an EA database  All large operational GISs are built on geodatabases;  Arguably the most important part of the GIS  Geodatabases form the basis for all queries, analysis, and decision-making.  A DBMS, or database management system, is where databases are stored.

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Complete EA map with all components overlaid on one map display Main components are: Street network, Buildings EA boundaries layer Annotation, Symbols, Labels Building numbers Neatlines Legend

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Components of a Hypothetical urban EA map

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Entity-Relationship Example: EA entity can be linked to the entity crew leader area. The table for this entity could have attributes such as the name of the crew leader, the regional office responsible, contact information, and the crew leader code (CL code) as primary code, which is also present in the EA entity. Crew leader area CL-code Name RO responsible 1-N EA EA-code Area Pop. 1-1 R

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Components of a digital geographic census database

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Different Geographies  A geography for data collection: EA level or even dwelling level  Another geography for data dissemination: Aggregated level (confidentiality)

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Digital Data Dissemination Users  The wide range of potential users of disaggregated census data means that the NSO needs to pursue a multi-leveled digital data dissemination strategy.  Broadly, we can distinguish between the following types of users: Advanced GIS users Computer literate users Novice users

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Uses of Graphs: Enriching the Understanding of GIS Data Sets  Exploratory Spatial Data Analysis  Linked Maps, Graphs & Tables  Dynamic Feature Selection  Animation  Visualization over Time

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 GIS capabilities: Visualization

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Spatial Analysis  Spatial Relationships (explicit -Topolgy) Logical connections between spatial objects represented by points, lines and polygons e.g.,- point-in-polygon; line-line; polygon-polygon  Geographic Database Geographic features selection Attributes Structure

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Spatial Operations  “adjacent to”  “connected to”  “near to”  “intersects with”  “within”  “overlaps”  etc.

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Spatial Analysis: Query  select features by their attributes: “find all districts with literacy rates < 60%”  select features by geographic relationships “find all family planning clinics within this district”  combined attributes/geographic queries “find all villages within 10km of a health facility that have high child mortality” Query operations are based on the SQL (Structured Query Language) concept

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Examples: What is at…? Features that meet a set of criteria

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 “is nearest to” Point/point Which family planning clinic is closest to the village? Point/line Which road is nearest to the village Same with other combinations of spatial features

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 “is near to”: Buffer Operations Point buffer Affected area around a polluting facility Catchment area of a water source

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Buffer Operations Line buffer How many people live near the polluted river? What is the area impacted by highway noise?

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Buffer Operations Polygon buffer Area around a reservoir where development should not be permitted

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 “ is within”: point in polygon Which of the cholera cases are within the containment area

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Spatial aggregation  Example of Spatial aggregation: fusion of many provinces constituting an economic region

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Spatial data transformation: interpolation Example: Based on a set of station precipitation surface estimates, we can create a raster surface that shows rainfall in the entire region

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Example of linear interpolation creating contours contour lines of elevation can be derived through linear interpolation from a satellite image

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Areas of influence  Commuting distances: daily commuters flow

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Modelling: smoothing  Evolution of the population beetwen two censuses

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Spatial Analysis Techniques  Cartograms sometimes used to display census results The areas of the original polygons are expanded or contracted based on their attribute values such as population size or voting habits

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 The Second Administrative Level Boundaries data set project (SALB)  The Second Administrative Level Boundaries data set project (SALB) has been launched in 2001 in the context of the activities of the UN Geographic Information Working Group (UNGIWG) and has for objective to provide access to a working platform for the collection, management, visualization and sharing of sub national data and information in a seamless way from the national to the global level.UN Geographic Information Working Group (UNGIWG)  unsalb.org

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Handbook on Geospatial Infrastructure in Support of Census Activities (2009) phic/standmeth/handbooks/default.htm

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 Issues for consideration  Do you have (or are you considering to have) a full digital Geographic Database for census operations?  Are you considering to use spatial analysis to suit specific user needs?  Are you partnering with other stakeholders (the public and private sector) in order to Build the NSDI Work jointly on coding efforts Produce value added products – higher demand for census data

United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis Bangkok, Thailand, 5-8 October, 2010 THANK YOU!