Introduction to GRASS GIS and QGIS

Dr. Huidae Cho
Institute for Environmental and Spatial Analysis...University of North Georgia

1   Open sauce?


2   Open source


Images under Creative Commons Licenses

3   Why open source?

Open source softwareCommercial software
Cost0\$\$\$ (e.g., ArcHydro: Single Use ArcGIS for Desktop Standard \$7,000 + Spatial Analyst \$2,500 = \$9,500)
SupportUser & developer communitiesCommercial support, User community
TroubleshootingReport to the community, Fix yourself, Hire developersReport to the company, Wait for free or paid updates if any
UILack of user friendliness, Learning curveUser friendly, Familiar
AlgorithmsPeer reviewed, Scientifically proven, TransparentBlack box, Only indirectly known through documents
ExtensibilityAPI, Open data formats, Can be integrated with other open source software (e.g., QGIS+GRASS)API, Proprietary SDK, Proprietary data formats
SummaryLow cost, May require expert helpHigh cost, Can use commercial support

4   Open source GIS





GRASS (Geographic Resources Analysis Support System)

Celebrated its 36 years in 2019!

First released on July 29, 1983 by the U. S. Army Corps of Engineers’ Construction Engineering Research Laboratory (USA/CERL)

brady-dem.png brady-dem-in-3d.png

In 1999, released under the GNU General Public License (an open source license)

Over 350 modules

Provides scientific modules to QGIS as plugins

Written in C, C++, Python, and wxPython

Python API

6   QGIS


Started as Quantum GIS in early 2002 by Gary Sherman

Integrates GRASS GIS modules for scientific analysis

More similar to ArcGIS 10 than to ArcGIS Pro

  • Single map pane
  • No ribbon UI, luckily!

Uses Coordinate Reference Systems (CRS)

Written in C++, Qt, and Python