What is Geospatial Data?

Everything Happens Somewhere

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Everything Happens Somewhere

As a result, practically all data has a spatial attribute (US Office of Management and Budget, 2002)

- Explicit (coordinates, addresses)

- Implicit (landmarks, directions)

- Inferred (creators, researchers, referees)

http://geography.oii.ox.ac.uk/?page=mapping-edits-to-wikipedia-from-africa

Inferred Spatial Context

Even if the subject at hand is not directly spatial, odds are

good that it has spatial context

- Where is this subject being created/studied?

- Any important places with references to this subject?

- Any important researchers/centres of excellence?

- Who is looking for information on this subject? http://geography.oii.ox.ac.uk/?page=the-location-of-

academic-knowledge

Sourcing Spatial Data

Ready to Use:

• Satellite imagery

• Climatic Data

• Census Data

• Elevation models

Reference:

• Topographic Map

Series

• Gazetteers

• Google Earth

Existing spatial data sets can be found locally (in libraries and data repositories) or via the Web

http://www.floatingsheep.org/2014/04/new-book-chapter-on-geographies-of-beer.html

Local names for “cheap” beer sourced via Twitter

Sourcing Spatial Data: The Web

Google search for mosquito densities leading to MosquitoMap.org

Ready to use data

Underlying dataset of land cover classifications can immediately be used in overlay analysis

Reference Data

The image of Pyongyang in 1950 provides context and meaning to a human observer but cannot be directly queried or used in a GIS analysis. Features would need to be traced off (digitized) into separate layers.

Creating Spatial Data:Geocoding

By using explicit coordinates, or looking up addresses or landmark locations referred to in reports and papers it is possible to create spatial attributes for data in practically any discipline.

Wireless Access Points, Jagger Library, 4th Floor via ICTS Website

Creating Spatial Data:Geo-tagging Audiovisual Data

It is also possible to geocode audio and video records:

• Through coordinates captured and stored by recording devices (such as modern smartphones and GPS data loggers)

• Retroactively by matching landmarks in the background of photographs, postmarks on postcards, references to locations in interviews or songs.

Map

Visual orientation is the most common operation

• “make a map of the study area”

• “make a context map showing the study area relative to landmarks/roads/provincial boundaries”

Sandy Shell, Oromo Slave First Passage Journal Analysis Study Area

Analyse

Mapping data is the first action, but by analysing it using spatial functions you are able to:

• append information from the surrounding spatial environment (overlay)

• analyse the spatial distribution pattern (geo-statistics)

• model or predict occurences (envelopes)

Sandy Shell, Oromo Slave First Passage Journeys

ShareOnce you have gone

to the effort of spatially locating data, creating maps or derivative data

SHARE IT!

The more spatial data available, and the easier it is to reach, the better it is for future research.

ArcGIS.com Map Gallery & MapTube.org

Reference your data

Spatial data is just like

any other sort of data

• It needs to be referenced/acknowledged

• It needs metadata in order to be assessed against future mapping or analytical needs (scale, date, original source, pre-processing)

How?Desktop

Use a GIS package on your PC/Mac/Tablet/Phone

• Free Desktop

Quantum GIS, Google Earth, uDig, MapWindow

• Expensive Desktop

ArcGIS, Autodesk, Illustrator Plugins, Ortelius, MapDraw

Quantum GIS & ArcGIS Interfaces

How?Web Based

Free Web

Google Fusion Tables, Map Engine

OpenStreetMap

GNSS (Geographic Name Servers)

Expensive Web

ArcGIS Online, WeoGeo, MangoMap

OpenStreetMap.org & MangoMap.com

Nicholas Lindenberg

Thomas Slingsby

Tel: 021 650 3917

Room 5.25 G.H Menzies Building

UCT GIS Lab