Higher Education Profiling using Open Source GIS - A Primer on OpenStreetMap Data, Mapnik & OpenLayers

Higher Education Profiling using Open Source GIS

A Primer on OpenStreetMap Data,

Mapnik & OpenLayers

Oliver O’Brien & Alex Singleton

Department of Geography

University College London

Contents

• The Problem• Requirements• The Solution

– OpenStreetMap Data– Mapnik– OpenLayers– Data Sources

• Putting it all Together• The Completed Atlas

The Problem: Presenting the Data

A large amount of education-related spatial information available from various governmental bodies but not in a readily accessible graphical form (i.e. maps) for non-technical users.

• Dept. for Schools, Children and Families• Communities and Local Government• Higher Education Funding Council for England• Higher Education Statistics Agency• Office for National Statistics

“Widening participation” initiatives require effective ways to view such data, to make decisions on target schools and areas.

Requirements I. Straightforward

Standalone GISes

Hard to use (Haklay, 2009a)

Often expensive

Require delivery of data to the client

Requirements I. Straightforward

Web GISes

Slow

Unattractive

Difficult and/or expensive to build

May require delivery of vector data to the client

Requirements I. Straightforward

“Slippy Maps”

Simple to use

Very popular

Simple to build

Powerful API (e.g. Google Maps API)

Requirements II. Accessible

Software installation– Requires time and skill– Constrained by platform

Plug-ins– Generally require a fast computer– Still some platform issues

A solution without installation or plug-ins is most accessible– HTML, CSS, AJAX– PNG images

Requirements III. Self Contained

• No dependencies on third parties with constraints– Ordnance Survey “tile limits”

• The “derived data” problem, Google and Ordnance Survey– Can’t put Ordnance Survey derived data

on a Google Maps “mashup”– Government departments often provide

data that has been geolocated from Ordnance Survey mapping (e.g. using National Grid References)

– Ordnance Survey is being very active at protecting use of its data at the moment

Requirements III. Self Contained

Full control over what’s on the mapGoogle’s colour scheme and branding can be distracting

The Solution: An Education Atlas

Static tiles of choropleth maps•Minimal computer requirements•Scalable

Mapnik•Makes “beautiful” raster maps

OpenStreetMap data•Easily available data source to create background maps•Full control over what is included

OpenLayers•Provides the “slippy map” interface familiar to users•Self-contained

Using OpenStreetMap Data

For a background map to provide context•Will include roads, town names, coastlines•We don’t want all the data – just what we need

Ways to obtain the data•Directly from osm.org as XML, requires converting•Shapefiles produced by CloudMade or Geofabrik

Data quality and completeness•Improving rapidly (Haklay, 2009b)•Now pretty good for England (Reed, 2009)•Can always obtain a very up-to-date dataset

www.openstreetmap.org

Using Mapnik

Data Sources•Shapefiles•PostGIS databases•Direct from OpenStreetMap

TilesCan be configured to systemically create square tiles at different zoom levels for the whole country

www.mapnik.org

“Mapnik is a Free Toolkit for developing mapping applications. Above all Mapnik is about making beautiful maps.” – mapnik.org

Using Mapnik

Stylesheets for the cartographye.g. minor rivers and canals

<Rule> <Filter>[waterway]='river' or [waterway]='canal'</Filter> <MaxScaleDenominator>80000 </MaxScaleDenominator> <LineSymbolizer> <CssParameter name="stroke">#88c <CssParameter name="stroke-width">3 <CssParameter name="stroke-linejoin”>round <CssParameter name="stroke-linecap">round </LineSymbolizer> <TextSymbolizer name="name" face_name="DejaVu Sans Book" size="10" fill="#666" halo_radius="1" placement="line" min_distance="200"/> </Rule>

Using OpenLayers

A way to display maps on a website•Just a simple web browser is needed

Accepts “layers” from many sources•Google Maps•Microsoft Bing, Virtual Earth, Yahoo•ArcGIS 9.3 Mapping Services•Ordnance Survey OpenSpace

More powerful (but more complex) than the popular Google Maps API

www.openlayers.org

Other Data Sources

New Popular Edition Postcoding

Government Data– Combined with UKBORDERS

boundary data, to create choropleths of each educational metric

– Includes the National Pupil Database with postcode, for Key Stage 4 (GCSE) and Key Stage 5 (A-Level)

Putting it all Together: Tile Generation

OpenStreetMap API

Geofabrik Shapefiles PostGIS

Database

Mapnik

Other .gov.uk

Stylesheet

mySQLDatabase

Tiles

DSCF.gov.uk

UKBORDERS

Shapefiles

Putting it all Together: The Website

OpenLayers

NPEMap Postcodes

mySQLDatabase

TilesWeb

Browsers

Bottom: Choropleth (colours)

Middle: Network (B&W)

Top: Schools (pins)

The layers in OpenLayers

The Completed AtlasIDACI in Hampstead vs. Willesden, London

The Completed AtlasA-Level French Popularity in S.E. England

Putting it all Together: The Completed AtlasA-Level Geography Popularity in England

The Completed AtlasOutput Area Classification in Manchester

The Completed AtlasIDACI in Manchester

The Completed AtlasGCSE Performance in Manchester

Problems

• No spatial data for independent schools or further education colleges – hence no A-Level metrics for Manchester

• Tiling process is quite slow and requires ~1GB of storage space for each choropleth set

Next Steps

• Bring in higher education flow data

• Incorporate individual school metrics

References

• Haklay, 2009a: Neo and Paleo GIS – is the difference in the usability culture? http://povesham.wordpress.com/category/gis-usability/

• Haklay, 2009b: OpenStreetMap and OS Master Map – Beyond good enough http://povesham.wordpress.com/2009/07/15/openstreetmap-and-ordnance-survey-master-map-–-beyond-good-enough/

• Reed, 2009: More on OSM Coverage http://tlatet.blogspot.com/2009/08/more-on-osm-coverage.html

Further Information

http://ollie.blogs.splintdev.geog.ucl.ac.uk/