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					Spatial Analysis & Dissemination of Census Data




  United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                              Amman, Jordan, 16-19 May, 2011
Outline


       Geographic Database

       Spatial Analysis Techniques

       Examples




United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                            Amman, Jordan, 16-19 May, 2011
Geographic Database



 Geographical features (Conceptual Model)
       Components selection
       Attributes
       Structure


 Spatial Relationships (explicit -Topolgy)




 United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                             Amman, Jordan, 16-19 May, 2011
Spatial relationships


 Logical connections between spatial objects represented
  by points, lines and polygons

 e.g.,
  - point-in-polygon
  - line-line
  - polygon-polygon




   United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                               Amman, Jordan, 16-19 May, 2011
    Complete EA map with all components overlaid
    on one map display
                                                                                                                                                                                                                                                                                       35                            31                            45
                                        27                                                                         61                                                                                                                         22
                                                                                                                                                              57                       65                             62                                                  19
                                                                  43
                                                                                          40
                                                                                                                                                                                                                                                                                                350                  32                                44           43
                                                                                                                                                                                                                                                                                                                                                                                       42          41

                                                                                                                                       349                     58                          64
                                                                                                                                                                                                                      63                                   21
                                                                                                                                                                                                                                                                          20
                                                                                                                                                                                                                                                                                           34                  33

                                         28                                                41                               60              59
                                                                       42
                                                                                                                                                                                                                      Eckert Drive                                                                                                                                                           6




                                                                                                                                                                                                                                                                                                                                                                      Clark
                                                                                                                                                                                                                                                                                                                      61
                                                                                                                                                                                                                                                                                                     60                                                      1




                                                                                                                                                                                                                                                                                                                                            Ortelius
                                                                                                                                                                                                                                                                     55




                                                                                                                                                                                                                                                                                                                                                                            e Str
                                                                                                                                                                                       6




                                                                                                                                                                                                                                                                                     Ptolemy
                                                                                                                                   4                      5                                                                7




                                                                                                                                                                                                                                                                                                                                                                                 eet
                                                                                               1                                                                                                                                                                                                                              62                                                            11




                                                                                                                                                                                                                                                                                                                                               Street
                                                                                                                                                                                                                                                                                                                                                            5         2




                                                                                                                                                                                                                                                                                       Street
                                              31                                                                                                                                                                                                                               56                    66
                                                                                                                                                                                                                                                                59



Main components are:
                                                                                                                                                               10                          9                               8
                                                                                                                                       11                                                                                                                                                                                                                                                         10
                                                                                                                                                                                                                                                                                                     65         64                     63                              3
                                                                                                                                                                                                                                                                     58                                                                                         4
                                                                                                                                                                                                                                                                                57
                                                                                                                                                          Tobler Street
                                                                                                                                                                                                                                                                                Gall Street




                                                                                                            Snyder St
                                                    37
                                                                                                                                       12                          13                                                           19                                                                                                                                  12
                                    42                                                                                                                                                                                                                                                              74          75                     67                                                        13
                                         358                                                   2
                                                                                                                                                                                                                 18                                                            73



Street network,




                                                                                                                                                                                       Krassows
                                                                                                                                                                                                                                                                 72
                                                                                                                                                                                                                                                                                                                                                                      362




                                                                                                                      ree




                                                                                                                                                                                                                                          Lambert Avenue
                                                                                                                                                                         14
                                              38                                                                                                                                                                                20




                                                                                                                  t
                                                                                                                                                                                                                 23                                                                                                                    68
                                                                                                                                                                                                                                                                71                                                                                                                 18




                                                                                                                                                                                               kij Street
                                                                                                                                                                                                                                                                                         69




                                                                       Merca
                                                         43                                        3                                   17                                    15                                   22            21
                                    51                                                                                                                16                                                                                                         70
                                                                                                                                                                                                                                                                                                          Cassini Drive

Buildings                                                                                                                                                                                                                                                                                                                                                                                          21




                                                                            tor Av
                                        45         44                                                                                                                                                                                                                                                                                                                                   20
                                                                                                                                                                                                                                                                                                                                                                      19
                                                                                                                                                          Cassini Drive                                                                                                                                  82
                                                                                                                                                                                                                                                                                      81                                76




                                                                                   enue
                                                                                                                                                                                                                                                                80                                                                                                    29
                                                                                                                                                                                           35                                   36
                                                                   21                                                   24                                     26
                                   19                                                                                                            25



EA boundaries layer                                                                                                                                                                                             361
                                                   20                                                                                                                                                                                                                                  79                 78                           77                               28
                                                                   22                                                                                                                                                                                                                                                                                                                             27
                                   23                                                                                                                                                                                            37
                                                                                                                                                                                                                                                                                    Mollweide Street
                                                    Street                                                                                                     27                                           43
                                                                   30                                  29                                  28
                                                        29                                                                                                                                                                                                                                                                                                              1                    2
                                                                                                                                                                                                                                 38                                            88                        83
                                    28                                 31                                                                                                                                                                                            87
                                                                                                                                           eet
                                                         32                                                                      Bonne Str                                                                  42



Annotation,




                                                                                                                                                                                                                                                                                                                                               iv      e
                                    33




                                                                                                                                                                              Goode




                                                                                                                                                                                                                                                                                                                                            Dr
                                                         Street                                                                                      32                                                                          39                                                                                                                              14
                                         Robinson                                                                                 31
                                                                                                                                                                        33                                                                                                     85                          84
                                                              41                                                                                                                                            41                                                   86
                                                                                                            30                                                                                                                  40                                                                                                                      13                              7
                                                                                                                                                34
                                                                                                                                                                                                                                                                                                    Miller
                                              374                                                                                                                                                                                                                                                                                            12



Symbols,                                                          42
                                                                                                                                                               Imhof Drive                                                                                                                     24
                                                                                                                                                                                                                                                                                                          15




                                                                                                                                                                                      Street




                                                                                                                                                                                                                                                                                                                      Grinten Street
                                                                                                                                                                                                                 51        52                                        23                                                                     11               10
                                          43                                                                                                         50
                                                                                                             48                        49                                                                                                                                                                                                                                          9              8
                                                                                                                                                                             44
                                                        eet
                                             Tissot Str                                                                                                                                                                          53
                                                                                                                                                                                                                 54
                                                                                                               47                      46             45



Labels
                                                    59         50
                                    58
                                                                   51
                                                                                                                                                                             Bessel Street
                                                                                                                                                                                                                                                                     22                                        16
                                                                                                                                                                                                                                                                                                                                        25
                                                                                                                                                                                                                                                                                                                                                 378                    26                   27


                                                                                                                                                      3                  4
                                                                                                                                       2
                                    54                         52
                                                                                                               1

                                                                                                                                                                                                            9
                                                                                                                                                                                                                  377                 10                             21
                                                                                                                                                                                                                                                                                                                                                 34                   33
                                                                                                                                                                                                                                                                                                                                                                                                 32




Building numbers                                              Enumeration Area Map
                                                        Province:                          Cartania                                            14
                                                                                                                                                                                                                                                                                                Symbols

                                                        District:                          Chartes                                            032                                                                                                               District                                       358                                           EA-Code

Neatlines                                               Locality:
                                                        EA-Code:
                                                                                           Maptown                                           0221
                                                                                                                                            00361                                                                                                               Locality
                                                                                                                                                                                                                                                                EA
                                                                                                                                                                                                                                                                                                                                                                Hospital
                                                                                                       N

Legend                                                                                                                                                                                                                               17
                                                                                                                                                                                                                                                                Building
                                                                                                                                                                                                                                                                number
                                                                                                                                                                                                                                                                                                                                                             Church

                                                                                                                                                                                                                                                                                                                                                             School
                                                                           Approximate scale
                                             0                      50                                 100                                                                   200m
                                                                                                                                                                                                                                     Census 2000                                                National Statistical Office - July 1998




  United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                              Amman, Jordan, 16-19 May, 2011
Spatial Operations

            “adjacent to”

            “connected to”

            “near to”

            “intersects with”

            “within”

            “overlaps”

            etc.



  United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                              Amman, Jordan, 16-19 May, 2011
 Spatial Analysis Techniques


 the main use of spatial analysis is for census
  products and services

 Techniques include: queries, distance
  measurements, buffering, linear interpolation, point
  pattern analysis, and cartograms, etc.

 All offer functionality beyond standard thematic
  mapping, with many tools now available in both
  commercial and open-source software programs.


  United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                              Amman, Jordan, 16-19 May, 2011
  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
                               Amman, Jordan, 16-19 May, 2011
Examples:                                                        Id
                                                                 Name
                                                                          0012376027
                                                                              Limop
                                                                 Population   31838
                                                                 Popdens        37.5
                                                                 Num_H         8719

                 What is                                         H
                                                                 Clinics           8



                 at…?


                                                              Population density
                                                              greater than 100
               Features that                                  persons/sqkm?

               meet a set of
               criteria




 United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                             Amman, Jordan, 16-19 May, 2011
   “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
                                Amman, Jordan, 16-19 May, 2011
    “is near to”: Buffer Operations


•    Point buffer

     •    Affected area
          around a Hospital

     •    Catchement area of
          a water source




    United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                                Amman, Jordan, 16-19 May, 2011
        “is near to”: Buffer Operations


•   Point buffer

    •     Affected area around a polluting facility

    •     Catchement area of a water source




        United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                                    Amman, Jordan, 16-19 May, 2011
    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
                                    Amman, Jordan, 16-19 May, 2011
    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
                                    Amman, Jordan, 16-19 May, 2011
Spatial Analysis Techniques

 point-in-polygon analysis
        Determines whether a point lies inside or outside a
         polygon.
        Can be used to compare geo-coded village centroids lying
         inside and outside hazardous areas such as tropical storm
         tracks or earthquake zones.
 Polygon overlay analysis
        Involves comparison between the locations of two different
         polygonal data layers.
        For example, the boundaries of two administrative districts
         could be compared to troubleshoot errors in the field
         enumeration process



 United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                             Amman, Jordan, 16-19 May, 2011
    “ 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
                                 Amman, Jordan, 16-19 May, 2011
Problem:
   We may have a set of point coordinates representing
   clusters from a demographic survey and we would like to
   combine the survey information with data from the
   census that is available by enumeration areas.


Solution:
 “Point-in-Polygon” operation will identify for each point
the EA area into which it falls and will attach the census data
to the attribute record of that survey point.



  United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                              Amman, Jordan, 16-19 May, 2011
   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
                                   Amman, Jordan, 16-19 May, 2011
   Spatial data transformation: interpolation

Example 1: Based on a set of station precipitation surface
estimates, we can create a raster surface that shows
rainfall in the entire region

13.5           20.1
                         26.0

 12.7                            27.2
            15.9
                        24.5
                                     26.1




       United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                                   Amman, Jordan, 16-19 May, 2011
               Example of linear interpolation creating contours




United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                            Amman, Jordan, 16-19 May, 2011
    Spatial Analysis Techniques

     Thiessen polygons
                                                            Thiessen polygons illustrated
         Have the unique property that
          each polygon contains only one
          input point (e.g. settlements),
          and any location within a
          polygon is closer to its
          associated point than to the
          point of any other polygon.

         This method assumes that the
          values of the unsampled data
          are equivalent to those of the
          sampled points.




     United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                                 Amman, Jordan, 16-19 May, 2011
Areas of influence

   Commuting
    distances: daily
    commuters flow




 United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                             Amman, Jordan, 16-19 May, 2011
 Modeling/Geoprocessing


 modeling: identify or predict a process that has created or
  will create a certain spatial pattern

       diffusion: how is the epidemic spreading in the province?
       interaction: where do people migrate to?
       what-if scenarios: if the dam is built, how many people will
        be displaced?




   United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                               Amman, Jordan, 16-19 May, 2011
Modelling: smoothing

   Evolution of the
    population
    beetwen two
    censuses




United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                            Amman, Jordan, 16-19 May, 2011
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
                             Amman, Jordan, 16-19 May, 2011
Location-allocation problems



 Site selection
 Optimal allocation
 Multicriteria Analysis




 United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                             Amman, Jordan, 16-19 May, 2011
Conclusion


 Geographic Database
 Topology
 Although spatial analysis is sometimes used during
  the enumeration phase (clustering, for example,
  can aid in identifying housing units to be
  canvassed), the main use of spatial analysis is for
  census products and services.
 Variety of techniques: buffering, overlay, modelling
 GIS: Decision making tool




 United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                             Amman, Jordan, 16-19 May, 2011
                          THANK YOU!




United Nations Regional Seminar on Census Data Dissemination and Spatial Analysis
                            Amman, Jordan, 16-19 May, 2011

				
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