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Grids and GeoStatistics

Vilni Verner Holst BlochMSc. landscape ecology and natural resourcesStatistics NorwayOtervegen 23N - 2225 KongsvingerTel : ++47 / 62 88 50 62 Fax : ++47 / 62 88 50 97 E-mail : vvh@ssb.no

Routines for delivering products to the

national spatial data interest/infrastructure community

http://www.stat.si/forumGs/

The European Forum for Geostatistics workshop in Bled, Slovenia 1rst – 3rd October 2008

The next step towards an integration of statistics and geography for sustainable development

Session 2: Concept for an integrated web solution / An infrastructure for geostatistics. (The Subproject 3)

A work in process

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Overview of the presentation

• Background – introduction

• Defining the grid

• Making guidelines for geostatistics

• Standards and metadata

• Confidentiality and quality

• Further work and deliveries

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Background

Statistics Norway

Registers on address levelPopulationBuildingsGround PropertiesSport facilitiesFarmsBusinesses

And many more

• Partnership in Norway Digital (obligations)

• Expressed needs from partners

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BackgroundDownload page for Norway Digital partners

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Background

• Formalising a national grid for geostatistics

• Internal drive within Statistics Norway (coming censuses, preparations for a geodatabase)

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Defining the grid

SSBgrid is an open-ended definition of a family of spatial tessellation models for use in Norway.

The models are all built with quadratic grid cells.

The naming convention of the grids is to use the grid cell size, measured as the length of a side of a grid cell in meters or kilometers concatenated to the capital letters ‘SSB.

cell size is also denoted K, and with either m or km to indicate length measure.

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Defining the grid

Grid name Cell size Number of cellsSSB100m (1) 0.01 km2 Approx. 35 000 000 cellsSSB250m (1) 0.0625 km2 Approx. 5 600 000 cellsSSB500m (1) 0.25 km2 Approx. 1 400 000 cellsSSB1km 1 km2 Approx. 350 000 cellsSSB5km 25 km2 Approx. 15 000 cellsSSB10km 100 km2 Approx. 15 000 cellsSSB25km (2) 625 km2 Approx. 500 cellsSSB50km (2) 2 500 km2 Approx. 150 cellsSSB100km (2) 10 000 km2 Approx. 40 cellsSSB250km (2) 62 500 km2 Approx. 10 cellsSSB500km (2) 250 000 km2 Approx. 4 cells

(1) Because of limitations in many software packages and for practical use, these grids are recommended as grids with a county coverage.

(2) These grids might also cover sea territories. Number of cells refers to coverage of Norwegian mainland. One has however to be aware of deviations in grid cell areas for regions remote from the Norwegian mainland and Svalbard.

A system of standard grids

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Identification

• The identification (ID) of a grid cell with its southwestern corner at [XC,YC] in an SSBgrid with grid cell size K is

Computational efficiency

• Since a false easting is needed to compute XC and YC for locations along the western coast of Norway, the false easting used in the ID should be also used for this purpose when the ID is calculated directly from point coordinates:

KK

YTruncK

K

XTruncID

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10102

CC YXID 713 10102

Defining the grid

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Defining the grid

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Defining the grid

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Defining the grid

Projection and datumAll SSBgrids are defined in UTM33/EUREF89.

ExtentionSSBgrids have no definite extention.

Exchange format

SSBgrids have no particular exchange format.

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Organisation – responsibility and contact points

• S320 Population statistics Paul Inge Severeide (Head of division)Gjermund Nygårdseter (GIS contact 62 88 52 25)

• S410 Enterprise registerJan Ole Furseth (Head of division)Beate Bartsch (GIS contact 62 88 50 38)

• S430 Agricultural statisticsOle Osvald Moss (Head of division)Anne Snellingen Bye (GIS contact 62 88 52 39)

• S460 Construction and services statisticsRoger Jensen (Head of division)Birgit Bjørnsgard (GIS contact 62 88 50 97)

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Quality checksUnits with coordinates # records in

original file# grid cells Dif. (n) Dif.(%)

Enterprises 2008 35 960 35 861 99 0,28

Population 2000 55 749 55 653 97 0,17

Population 2001 55 992 55 797 196 0,35

Population 2002 55 946 55 812 134 0,24

Population 2003 56 829 56 743 87 0,15

Population 2004 55 805 55 721 85 0,15

Population 2005 55 672 55 588 85 0,15

Population 2006 55 703 55 616 88 0,16

Population 2007 55 572 55 489 53 0,10

Population 2008 55 546 55 467 80 0,14

Buildings 2006 115 801 115 370 434 0,37

Buildings 2007 116 170 115 738 435 0,37

Buildings 2008 116 509 116 130 382 0,33

Farms 1999 33 406 33 309 98 0,29

Farms 2006 26 993 26 909 84 0,31

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Confidentiality rules

Population by 1 square kilometre grid. Finnmark county. 1.1.2008.

Enterprises No lower limit

Population 1 – 9 => 5

Buildings No lower limit

Farms No lower limit

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Metadata

Task: To transfer existing metadata to an xml-document

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Metadata

Lots of standards and tools

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Metadata editor – INSPIRE online

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Metadata editor – ESRI ArcGIS

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Metadata editor – ESRI ArcGIS

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Metadata editor – OS MapWindow GIS

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Example : UML modell for adm. boundariesMetadata

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Are people blue in Java?

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… and red in Japan?

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Example: Identification of residents within a distance from a hospital.

•Use•Presentation•Delimitations•Interpretation

Making guidelines

Article in print

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From noise to information

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Preliminary suggestions

TopographyPopulation

Bathymetry

Employees

Buildings

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Possible future deliveries

• Households

• Dwellings

• Income

• Migration

• Education

• Agricultural statistics

• Historical statistics

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Further work and cooperation

• Products developed in cooperation with users

• Enhanced metadata

• Improve quality checks and measures

• Make guidelines for use of products

• System for exchange of data

Thank you

☺