Quantum GISz
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Transcript of Quantum GISz
Quantum GIS, which is often called QGIS, is an open source GIS
desktop application. Comparing to ArcGIS, QGIS can be installed on
various operating systems, such as Windows, Mac OS X, Linux
(Ubuntu), and Unix. More importantly, QGIS is free and has many
plugins, adding different functions. However, since QGIS mainly
relies on community support and voluntary developers.
Different operations using QGIS.
• Dealing with Vector Layer Attributes
• Dealing with Vector Geometries
• Spatial Analysis
• Dealing with Raster
• Projections
• File conversions
• Map Creation
Introduction
Topology expresses the spatial relationships between connecting or
adjacent vector features (points, polylines and polygons) in a GIS.
Topological or topology-based data are useful for detecting and
correcting digitizing errors. Topology is necessary for carrying out
some types of spatial analysis, such as network analysis.
There are 20 rules for point, line and polygon in QGIS
In QGIS topology can apply simply on shapefile while in ArcGIS
topology can not apply without making database. QGIS topology
"must not have gaps" don’t consider ring polygons/ donuts polygons
as topological errors. QGIS shows errors along AJK, GB and
Occupied Kashmir. Value of cluster Tolerance in arc map is limited
to 0.0000009.Where as in QGIS it is much lower, we can say it is
zero because tolerance does not effect the topology errors in
QGIS. These gaps are very small and are visible at around 1300:1
sacle ratio. Due to high cluster tolerance arc map is not marking it
as errors.
Topology
Map Components
• The title of the map.
• The scale of the map.ss
• The North Arrow .
• The Legend .
• The reference.
ArcGIS has better annotation capabilities. There are more native cartographic output options with ArcGIS
Mapping
Network Analysis
Calculating the shortest distance between two points is a commonly
cited use for GIS.
Use Road Graph plugin to calculate shortest distance in QGIS.
There are some other network analysis modules in
ArcGIS other than shortest and fastest route generation,
which can not be done in QGIS.
1.New Surface Areasssss
2.Closet Facility
3.New OD Cost Matrix
4.New Vehicle Routing Problem
5.New Location-Allocation
Dark blue points show facilities and light blue point show incident
Network Analysis
Q GIS VS Arc GIS
• QGIS, is an open source GIS desktop application while ArcGIS is a
commercial GIS software.
• QGIS has less processing time than ArcGIS.
• QGIS is easy to use.
• QGIS is a freely downloadable open source GIS software while
Esri’s ArcGIS is a commercially available suite of software.
• QGIS can be loaded on any computer. ArcGIS is restricted
through a seat license.
•There are Plugins in QGIS while in ArcGIS tool boxes are used.
• QGIS is developed has a paid core of developers but also
depends in part on volunteers. ArcGIS is a commercial GIS
software package developed by paid staff members of Esri.
• QGIS is cross-platform and can be installed and run on
Windows, Mac, or Linux machines while Esri’s ArcGIS for Desktop
only runs in a Windows PC environment
• QGIS has a faster startup time than ArcGIS.
• In QGIS topology can apply simply on shapefile while in ArcGIS
topology can not apply without making database.
• ArcGIS has better annotation capabilities. There are more native
cartographic output options with ArcGIS
• ArcGIS has more out of the box spatial analytic
capabilities: hillshading, to overlays, map algebra, surface
approximation, network analysis.
References
• https://hub.qgis.org/wiki/17/How_do_I_do_that_in_QGIS
• http://www.qgis.org/en/site/forusers/download.html
•http://manual.linfiniti.com/en/create_vector_data/topo_editing
.html
• http://qgis.spatialthoughts.com/2012/06/making-maps-for-
print-using-qgis.html
• http://qgis.spatialthoughts.com/
• http://www.qgistutorials.com/en/docs/making_a_map.html
• https://sites.google.com/site/ochaimwiki/geodata-preparation-
manual/how-to-check-topology-using-arcgis
• http://docs.qgis.org/2.0/en/docs/user_manual/
Contact
Roll No SS10-03
Department of Space Science, Punjab University Lahore
Email address
Conclusion
QGIS is an open source. It is easy to use. We can do a lot of
analysis by QGIS easily. It’s processing time is very short as
compare to ArcGIS. More plugins for QGIS are making by
developers all over the world.But prefer ArcGIS on QGIS because
ArcGIS is a professional software. It has more tools than QGIS. It
has more options for Spatial analysis , cartography and more
analysis.ss
Submitted by: Ayesha Rana Anwar
Submitted to: Sir Shahid Parvez
Quantum GISz
Mapping in ArcGISMapping in QGIS
Shortest Distance in ArcGISShortest Distance in QGIS
Topology errors In QGIS
Topology errors in ArcGIS
New closet Facility in ArcGIS