Web Mapping

April 7, 2016

Jennings Anderson

Project EPIC

Empowering the Public With Information in Crisis

We study the use of social media and social computing platforms during disasters and crisis

These slides available here:

Geo Spatial Oriented Crisis Informatics...Twitter! Geographic Filtering for Crisis Informatics....

Mapping on the Interwebz

What is a WebMap?

A Very Different Type of Geo Data...

  1. View Page (Request)
  2. Server Response
  3. Client Render

Or in other words, a web page

Tile Servers

So you want to show a map on a web page...

Tiles = Images

Tiles = Images

Tiles = Images @ Different Zoom Levels

Live Example...

New: Vector Tiles!

We just saw png tiles...

Vector Tiles,-105.2382052,11.45z

The tile data itself is vector data, your browser does the rendering.

Vector Maps at Mapbox

OSM in 5 Words






Wikipedia of Maps

OSM Community

Go to:

Getting Started Resources

  2. OSM Wiki's Beginner's Guide
  3. OpenStreetMap Wiki

A Totally Different Data Model

Traditional GIS Models:

  • Point
  • Line
  • Polygon
  • MultiPoint
  • MultiLineString
  • MultiPolygon

Things are different in OSM...

and this can drive GIS people crazy

OSM Data Model

OSM Database

OpenStreetMap in Action!

Crisis Mapping

Want OSM Data?

QGIS -> Vector -> OpenStreetMap -> Download Data...

Or in bulk: Mapzen Extracts
Download the Planet!


  1. There is a whole lot more to take away from GeoSpatial Data than Lat / Lon
  2. Open Data, Open Mapping
  3. Social GeoSpatial Data Analysis
  4. Maptime Boulder