Mapping Your DataMapping Your Data

Christopher Martincsmartin@buffalo.edu

Christopher Martincsmartin@buffalo.edu

About MeAbout Me

Geography MajorComputer Science Minor

Geography MajorComputer Science Minor

OutlineOutline

Data Types/ModelsData SourcesMap TypesDemos

Data Types/ModelsData SourcesMap TypesDemos

Tools of the TradeTools of the Trade

Cartographic SoftwareArcMapOther

(uDig, QGIS, GRASS)

“Mapping” Libraries/ToolsGoogle Earth, Google Maps,

OpenLayers

Cartographic SoftwareArcMapOther

(uDig, QGIS, GRASS)

“Mapping” Libraries/ToolsGoogle Earth, Google Maps,

OpenLayers

Data ModelsData Models

Two primary data models used when making mapsRaster DataVector Data

Two primary data models used when making mapsRaster DataVector Data

Raster DataRaster Data

Consists of discrete cells (think graph paper) Each cell has a discrete valueOccur in rows and columns

ExamplesImages (all image types)DEM

Consists of discrete cells (think graph paper) Each cell has a discrete valueOccur in rows and columns

ExamplesImages (all image types)DEM

Vector DataVector Data

Each position is represented by coordinates

Coordinates are connected to form lines or polygons

Points, lines and polygons are then used to represent geographic features

ExamplesShapefile

Each position is represented by coordinates

Coordinates are connected to form lines or polygons

Points, lines and polygons are then used to represent geographic features

ExamplesShapefile

Points, Lines, PolygonsPoints, Lines, Polygons

Data SourcesData Sources

US Census BureauNot just population data Generalized Boundary Data

ESRITIGER/LINENED DataFEMA Q3 Flood Data

USGSSEAMLESS Distribution

US Census BureauNot just population data Generalized Boundary Data

ESRITIGER/LINENED DataFEMA Q3 Flood Data

USGSSEAMLESS Distribution

Data Sources (cont’d)Data Sources (cont’d)

NYS GIS Clearing HouseMembership requiredWide variety of data

CUGIRNYS and National dataFree, huge variety

CIGARWorldwide Elevation Data

Columbia University EDSElectronic Data Service

NYS GIS Clearing HouseMembership requiredWide variety of data

CUGIRNYS and National dataFree, huge variety

CIGARWorldwide Elevation Data

Columbia University EDSElectronic Data Service

Data Sources (cont’d)Data Sources (cont’d)

Geography NetworkAggregates data from different

providersOnline Map Server Available

Geography NetworkAggregates data from different

providersOnline Map Server Available

Data QualityData Quality

Meta DataData about the dataAll legitimate providers will provide

thisAvailable for download or online

viewing

Meta DataData about the dataAll legitimate providers will provide

thisAvailable for download or online

viewing

Map TypesMap Types

Thematic MapsNot reference maps

Four main typesChoropleth MapProportional MapIsarithmic Map (contour)Dot Map

Thematic MapsNot reference maps

Four main typesChoropleth MapProportional MapIsarithmic Map (contour)Dot Map

Choropleth MapChoropleth Map

Shaded AreasThe “color” of the shade varies based

on measurement of our variable

Shaded AreasThe “color” of the shade varies based

on measurement of our variable

Isarithmic MapIsarithmic Map

Also known as Contour MapsWe draw lines to

connect separate variables that have the same value

Also known as Contour MapsWe draw lines to

connect separate variables that have the same value

Proportional Symbol MapProportional Symbol Map

Uses symbolsThe size of the

symbol varies according to the variable

Uses symbolsThe size of the

symbol varies according to the variable

Dot Density MapDot Density Map

Uses dotsSize is uniform,

but the concentration represents changes in the variable

Uses dotsSize is uniform,

but the concentration represents changes in the variable

CartogramsCartograms

Are NOT mapsArea is not preservedArea of the geographic regions varies by

variable

Two primary typesArea

Area gets larger or smaller depending on the variable

DistanceNodes or places can be closer or farther depending on

realtive distance

Are NOT mapsArea is not preservedArea of the geographic regions varies by

variable

Two primary typesArea

Area gets larger or smaller depending on the variable

DistanceNodes or places can be closer or farther depending on

realtive distance

CartogramCartogram

File FormatsFile Formats

ShapefileA collection of points, lines and polygonsTabular data values assocated with each

DEMRaster data, each cell represents

elevationComes in different resolutions

ShapefileA collection of points, lines and polygonsTabular data values assocated with each

DEMRaster data, each cell represents

elevationComes in different resolutions

Demo Time!Demo Time!

Gathering DataConverting Data

GeocodingGetting Data Into Arc Map

Making a MapArcMapGoogle EarthGoogle Maps/OpenLayer

Gathering DataConverting Data

GeocodingGetting Data Into Arc Map

Making a MapArcMapGoogle EarthGoogle Maps/OpenLayer