INTRO TO SPATIAL DATA ANALYSIS

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Content

Modeling our World Modeling our World with GIS Spatial Questions vs. Attribute Questions Results Terms to Know

Coordinate Reference System (CRS) Geographic Coordinates Projection

Shapefile Layer

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Modeling our World

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We describe any element of our world in 2 ways:

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Modeling our World with GIS

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A Geographic Information System (GIS) links location data and attribute data

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Spatial Questions vs. Attribute Questions

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In a GIS data can be queried spatially or by attributes:

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Results

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Terms to Know

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Coordinate Reference System (CRS) Geographic Coordinates Projection

Shapefile Layer

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Terms to Know – Coordinate Reference System

Geographic Coordinates 0° (Degree) Latitude Equator 0° (Degree) Longitude Greenwich (GB) Ottawa: 45°N, 75°W

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NEVER MEASURE IN DEGREES!!

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Terms to Know – Coordinate Reference System

Map Projections Method to represent

the surface of a sphere(3D) on a plane (2D)

Coordinates are now in measurement units like meters, km, feet, miles,… JOU-1526 Computer Assisted Reporting

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Terms to Know – Coordinate Reference System

Projected [m] Unprojected [degrees]

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Projections always distort surfaces!

Different projections based on location and purpose of map

Terms to Know – Coordinate Reference System

• Shape• Area• Direction• Size

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Terms to Know - Shapefile

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File containing information about the shape of objects, their attributes and locationsShape

Polygon

Line

Point

Location

Geographic Coordinates in Latitude / Longitude

Projected Coordinates in Measurement Units

Address

Attributes

Any kind of detail about the feature: height, length, name, color, etc.

File_Name.shp

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Terms to Know - Layer

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Represent the World as Layers of Information or Themes

Layers are saved as Shapefiles

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QGIS 1.8 Lisboa

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TOC = Table Of Contents

Shapefiles and Tables show here as so called “Layers”.

Main Window or Canvas

Data display area.

Coordinates and ScaleCoordinate Reference

System (CRS)

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References

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Map Projections: http://egsc.usgs.gov/isb/pubs/MapProjections/projections.html

http://www.electoralgeography.com/new/en/countries/c/canada/canada-legislative-election-2011.html

http://datajournalism.stanford.edu/ http://votecompass.ca/