Slithering into GIS - An intro to making maps with Python

by Clinton Dow

An introduction to GIS concepts and how Python fits in to the picture

• Many different backgrounds and experience levels
• Not much code, introducing the concepts instead!

• About me
• What is GIS Anyways?
• Geospatial Developers
• Python in GIS
• Python Geospatial Libraries
• Geospatial Data
• Databases
• On the web
• Geospatial is just getting started!

About me

• Computer nerd for basically my whole life
• Python Programmer for approximately 5 years
  • Started because of Civilization IV & V video game
    • Programming for fun becomes programming for profit

• Python product engineer
  • Works with Python nearly 40 hours per week

• Attends numerous tutorials, conventions etc
  • Great way to build your skills quickly
  • Meet like-minded people who will inspire you!

What is GIS anyways?

Geographic Information Systems

• An evolving field of study
• Not any one specific software platform, job or technique
• How to represent geospatial data as information
• Kind of like defining 'Programming'

Some concepts that fall under Geographic Information Systems

• Data Collection
• Geoprocessing
• Geocoding
• Cloud Computing
• Cartography
• Data Visualization
• Big Data
• Many more...

GIS is found in, or supports every major (and many minor) organization and business

• Government
• Armed Forces
• Natural Resources
• Utilities
• Financial
• Engineering and Construction
• Environmental
• Marketing
• Insurance
• Real Estate
• Supply Chain Management
• Telecom

A Geographic Information System

• An implementation of one or more concepts from GIS
• Commonly refered to as GIS Tools or GIS Applications

Many different GIS applications have become part of our lives

• News
• Traffic
• Weather
• Social Networking
• Dating

GIS Tools often work together as a GIS platform.

GIS Platforms are like IDEs for GIS.

• ArcGIS
• QGIS
• Mapbox
• PostGIS
• Google Earth
• ENVI
• Feature Manipulation Engine (FME)

All major GIS platforms have Python API/SDKs

Many GIS Developers customize GIS Platforms.

• Scripting GIS Tools
• Modifying functionality
• Developing plugins
• Combining multiple platforms' functionality

GIS/Geospatial Developers

Are in high demand!! Especially those with demonstratable Python skills.

Python can be found in almost all facets of Geospatial Development:

• Web GIS
• App development
• Embedded systems
• IoT
• Data Dashboards
• Geoprocessing
• etc..

It can be a demanding role, but very rewarding!

• Requires knowledge of geography and programming, often additional skills
• Constantly evolving field
• Supports many different industries and organizations
• Vaguely defined role at many companies

• Many new and exciting opportunities
• Never boring
• Outstanding potential for entrepeneurs
• Define your own role!

How does Python fit into all of this?

• A powerful and robust language out of the box
• Many open-source geospatial libraries
• Supported by every major GIS Platform (API/SDK)
• Supported by every major Database Platform
• Powerful web frameworks
  • Django for fully featured web applications
  • Flask for service-oriented web APIs
• Involved, passionate community

Python Open Source Geospatial Libraries

Reading and Writing Geospatial Data

• GDAL/OGR
• Fiona

These libraries allow you to work with various data types that are not accessible in pure Python.

Projections

• pyproj

A projection defines how the spherical surface of the earth is displayed on a flat surface

• Paper maps
• Computer Screens

Analyzing and Manipulating Geospatial Data

• Shapely
• PySAL
• Pandas/Geopandas

Perform Geoprocessing, joins and relates and map algebra on geospatial data.

Plotting Geospatial Data

• Mapnik
• matplotlib w/ Basemap Toolkit & pyplot
• Descartes

Draw the actual map on the screen.

Geospatial Data

Two main categories of Geospatial Data

Vector Data

• Points, Lines and Polygons
• Individual features hold values
• Locations of addresses
• Road Networks
• Boundaries
• Discrete data

Raster Data

• 'Grids' of data
• Cells hold values
• Images
• Height maps
• Temperature maps
• Continuous data

Sources of Vector Data: OpenStreetMap World Borders Dataset Twitter (Location-enabled Tweets) Government open data portals GPS Points Survey Data

Sources of Raster Data: Satellite Photography LandSat Natural Earth Aerial Photography Sensor Arrays (ie: Weather Sensors) National Elevation Dataset

Databases

Geospatial Databases are just regular databases with geospatial querying/indexing capabilities. Every major geospatial database has a Python API

Examples of Python APIs for geospatial databases:

- SQLAlchemy
- arcpy
- psycopg
- cartodb-python
- cloudant-python
- etc

Two main things that make a database 'geospatial':

• Spatial Indexes
• GIS Metadata
• Can be a relational or NoSQL database

Relational

• MySQL
• Postgre/PostGIS
• Oracle
• etc

NoSQL

• CartoDB
• CouchDB
• Cloudant
• etc

On the web

Web GIS is a huge area of growth in the geospatial industry.

• Not just webmaps
• Apps
• Dashboards

Web frameworks allow you to build your own web GIS tools and platforms.

Web GIS tools are typically offered as endpoints in a Service Oriented Architecture (SOA) model

• REST
• SOAP

Frameworks

• GeoDjango
• Folium
• Papyrus

Web GIS Platforms offer pre-created services for use with your data.

Platforms

• ArcGIS Online
• Boundless (OpenGeo)
• Mapbox
• Google Maps
• GeoServer
• Many more...

Wrapping it all up

Geographic Data

The 'Geography' in Geographic Information Systems

• Data acquisition
  • Surveying
  • GPS
  • Location-enabled Apps
• Data representation
  • Vectors
  • Rasters
  • Projections

Data != Information

The 'Information' in Geographic Information Systems

• Converting raw data into meaningful information
  • Databases
  • Services
• Using techniques such as
  • Geoprocessing
  • Spatial statistics
  • Map Algebra
  • Joins & relates
  • Queries
• Represented via
  • Charts and graphs
  • Cartography

Content Delivery Systems

The 'Systems' in Geographic Information Systems

• How do you deliver the information to a user?
  • Paper maps/atlases
  • Webmaps
  • Dashboards
  • Applications
• Supported by
  • Improved publishing process
  • Web server administration
    • DevOps
  • System Security
  • Wearables
  • Ubiquitous computing

The future of GIS is very promising!

• Proliferation of location-enabled devices
• Big Data
• Cloud computing
• Machine learning
• Virtual Reality/Augumented Reality
• Ubiquitous Computing

Plenty of opportunities in GIS Development

• One of the largest growth occupations in recent years
• Innovative products and ideas
• Tons of open source projects
• Opportunities in all aspects of I.T. and Development.

Finding a job as a GIS Developer

• Meetups
  • Try to meet at least one new person at each meetup!
• Open source
• Conferences
  • Esri UC
  • PyCon

Thank you for coming!

Slides available at - Contact Information - clint@datanavigator.ca

                - @DataNavigator