© Arthur J. Lembo, Jr.
Salisbury University
Exploring Free and Open
Source GIS
© Arthur J. Lembo, Jr.
Salisbury University
What is FOSS4g
• The acronym for Free and Open Source
Software for Geospatial (FOSS4g).
• Includes technology stacks for
– Desktop
– Server
– Developer
© Arthur J. Lembo, Jr.
Salisbury University
Why should I care about GIS
and FOSS4g?
• GIS is a multi-billion dollar industry.
• GIS is used in every State, and virtually
every county in the United States.
• While you customers might not appreciate
the advances in your surveying technology,
they are aware of GIS, and see a need for it –
you can provide value added benefits to
your existing contracts.
• Perhaps another way to open your business
to more customers.
© Arthur J. Lembo, Jr.
Salisbury University
Why should I care about GIS
and FOSS4g?
• Commercial GIS software is great (sometimes).
But, it is also expensive.
• Depending on what you need to do, commercial
software might be your only option.
• Open source software is great (sometimes), but it
is free.
© Arthur J. Lembo, Jr.
Salisbury University
FOSS4g vs. and Commercial
• Desktop
• Server
• Developer
• Desktop
• Server
• Developer
© Arthur J. Lembo, Jr.
Salisbury University
Can FOSS4g really do everything
that commercial software does?
• No…
• and Yes
• or less
• or more
• It is no longer a question of either/or,
but rather both.
© Arthur J. Lembo, Jr.
Salisbury University
What is QGIS?
• QGIS is a free, user-friendly Open Source
Geographic Information System (GIS).
• Latest release QGIS 3.8• Runs on Linux, Unix, Mac OSX, Windows and Android.
• Supports numerous vector, raster, and database formats.
• Runs in 32 and (true) 64-bit versions.
• QGIS manages raster, vector, and attribute data.
Also works within an enterprise setup.
• QGIS Help Documentation
© Arthur J. Lembo, Jr.
Salisbury University
What is Postgres?
• Postgres is a free enterprise class database.
PostGIS is the spatial extension for
Postgres, allowing you to incorporate spatial
operations in an enterprise database.
• Postgres is the most used open source
database in the world.
• New additions to Postgres now incorporate
the ability to work with really large
databases.
© Arthur J. Lembo, Jr.
Salisbury University
What is Geoserver?
• Geoserver is a free server side application
for performing cloud-based geospatial
analysis.
• Geoserver works with multiple software
products in a client-server relationship,
allowing you to deliver geospatial solutions
over the Internet.
© Arthur J. Lembo, Jr.
Salisbury University
What are some other FOSS4g
software• GRASS
• SAGA
• GDAL
• Many others….
© Arthur J. Lembo, Jr.
Salisbury University
QGIS
© Arthur J. Lembo, Jr.
Salisbury University
Let’s get some data
https://imap.maryland.gov/Pages/default.aspx
© Arthur J. Lembo, Jr.
Salisbury University
So. Many. Menus.
© Arthur J. Lembo, Jr.
Salisbury University
Toolbars
• Project
• Map Navigation
• Attributes
• Digitizing
• Data Sources
• Manage Layers
• Discover other toolbars
(web)
© Arthur J. Lembo, Jr.
Salisbury University
Reading in GIS data – just
like a grown up• ESRI Geodatabases
• ESRI Shape files
• Raster data sources
• Postgres databases
• AutoCAD (Baltimore County)
• Online GeoJSON
https://data.imap.maryland.gov/datasets/maryland-critical-areas-critical-area-towns
© Arthur J. Lembo, Jr.
Salisbury University
Editing GIS data – just like a
grown up
• Add, move, reshape, and delete
• Merge, split, and
• Snapping and topological editing
© Arthur J. Lembo, Jr.
Salisbury University
Performing Vector operations• Vector
– Spatial Query
• vector selection – by location
• vector selection – by attribute
– Research tools
• Random points
– Geoprocessing
• Buffer, clip, dissolve
– Geometry tools
• Centroids, polygons to lines
– Analysis tools• Count points in polygons
• Nearest neighbor
– Other tools• Split vector layer (then export)
© Arthur J. Lembo, Jr.
Salisbury University
Raster in QGIS
© Arthur J. Lembo, Jr.
Salisbury University
Getting the data in
• FUSION
– Developed by USDA
– Another QGIS plug-
in
2.
1.
1.
© Arthur J. Lembo, Jr.
Salisbury University
Models in QGIS
© Arthur J. Lembo, Jr.
Salisbury University
Raster analysis
© Arthur J. Lembo, Jr.
Salisbury University
Plug-ins – try that with
another GIS
• Openlayers
• Open Route Service
• Cartograms
• Geocoding
• Fusion
© Arthur J. Lembo, Jr.
Salisbury University
Routing in QGIS
gisadvisor.com, LLC.
Determine shortest paths and create isochrone maps with QGIS
© Arthur J. Lembo, Jr.
Salisbury University
Network analysis
© Arthur J. Lembo, Jr.
Salisbury University
Municipal Risk
Exploration of vector functions in QGISFor this exercise, you will explore the use of vector analysisto determine at-risk properties in certain flood zones, andcategorize the data. Let’s assume our stakeholders areinterested in:
• The total value of all land within the ‘AE’ floodzone.
• The total value of residential properties in the ‘AE’flood zone.
• The amount of residential land in the ‘AE’ floodzone.
© Arthur J. Lembo, Jr.
Salisbury University
Steps to complete analysis –
the hard way• Select the AE zone in firm (select features using an
expression from the table).
• Select parcels that intersect AE zone (spatial
query).
• Calculate the total value for the land (show
statistical summary).
• Select the residential properties from the previous
subset.
• Calculate the total value for the land.
• Use Group Statistics (under vector) to determine
the land value for all parcels in the AE zone.
© Arthur J. Lembo, Jr.
Salisbury University
Analytical steps
• Select the ‘AE’ zone
© Arthur J. Lembo, Jr.
Salisbury University
Analytical steps
• Select parcels in the ‘AE’ zone
© Arthur J. Lembo, Jr.
Salisbury University
Analytical steps
• Total value all land
© Arthur J. Lembo, Jr.
Salisbury University
Analytical steps
• Total value of Residential
© Arthur J. Lembo, Jr.
Salisbury University
Analytical steps
• Total Value of all land use
© Arthur J. Lembo, Jr.
Salisbury University
The easy way
© Arthur J. Lembo, Jr.
Salisbury University
Conclusion
• FOSS4g provides an excellent
vehicle for getting into the GIS game.
• Adding GIS capabilities to your
organization can help you stay
competitive, and provide value
added benefits to your clients.
• It isn’t a competition (at least it
shouldn’t be) – use what is best for
your business.