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Dissemination with GIS. United Nations Statistics Division 2010 World Programme on Population and Housing Censuses: Subregional Workshop on Census Cartography and Management 22-26 October, 2007, Port-of-Spain, Trinidad and Tobago. Census dissemination.
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Dissemination with GIS United Nations Statistics Division 2010 World Programme on Population and Housing Censuses: Subregional Workshop on Census Cartography and Management 22-26 October, 2007, Port-of-Spain, Trinidad and Tobago Workshop on Census Cartography and Management - October 2007
Census dissemination • A census is not complete until the data collected is made available to potential users in a form suited to their needs • The data may be: • included in published tables and reports for general distribution • produced as tables in unpublished form for limited distribution • stored in a database and supplied upon request, or disseminated online (in this case it will be available only to connected populations) Workshop on Census Cartography and Management - October 2007
Census geographical units • The census provides information at any geographical level, pre-defined or user-defined Workshop on Census Cartography and Management - October 2007
The power of maps • Maps visually communicate a concept or an idea • Maps summarize large amounts of information concisely • Maps are often meant to support textual information • Maps can be used for description, exploration, confirmation, tabulation • Maps encourage comparisons: • Between different areas on the same map: where are population densities highest? • Between different maps: is child mortality higher in the districts of province A than in province B? • Same area: where and by how much do literacy rates for males and females differ in the districts? • Between maps for different time periods: did fertility rates decline since the last census? Workshop on Census Cartography and Management - October 2007
GIS provide advanced functionalities for census dissemination • Combination of: • Census database: data at any geographical level • Geographical database: geographical structure of the country + cartographic representation Workshop on Census Cartography and Management - October 2007
Different Uses of Maps • Geographical selection • Direct selection of a user-defined area • Area delineation • Buffer zone • Areas of influence • Modelling: spatial smoothing Workshop on Census Cartography and Management - October 2007
Geographical selection Use this map to navigate to your area of interest by drilling down to the Geographic Areas that you require. Workshop on Census Cartography and Management - October 2007
Direct selection of a user-defined area... • The user describes the area on which he needs aggregated data by clicking on the components: for example, municipalities Workshop on Census Cartography and Management - October 2007
Area delineation • E.g. Interactive determination of school districts by looking at the number of children in each school and then aggregating census enumeration areas Workshop on Census Cartography and Management - October 2007
Buffer zone • How many people live within a five mile radius from the hospital ? Workshop on Census Cartography and Management - October 2007
Areas of influence • Commuting distances: daily commuters flow Workshop on Census Cartography and Management - October 2007
Modelling: spatial smoothing • Growth rate of the population between two censuses Workshop on Census Cartography and Management - October 2007
Uses of Graphs: Enriching the Understanding of GIS Data Sets • Exploratory Spatial Data Analysis • Linked Maps, Graphs & Tables • Dynamic Feature Selection • Visualization over Time • Animation Workshop on Census Cartography and Management - October 2007