2. Gdev QGIS Training manual 1
This training is for both highly skilled and newbies of QGIS.
The course outline covers many capabilities of the software
that can tackle simple and complex GIS tasks.
Pre-requisites:
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Basic GIS knowledge
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PC
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spatial data
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Interest & Concentration
3. Gdev QGIS Training manual 1
Key Skills
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Participants will acquire the following key skills:
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attribute data manipulation
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Working with various file formats
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Using the select by expression feature and field calculator
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Plugin installation and utilization
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Vector and raster styling
5. Lesson 1: Attribute data manipulation
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Open data in QGIS (Layer>add vector layer)
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Right click on layer and select open attribute table
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Double click on column to change order of data
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Select features using an expression
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Expand Fields & Values function list. Double click on pop_max
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Type in expression (pop_max>100000) and click select. This
selects towns with a population greater than 1000000.
6. Lesson 1: Attribute data manipulation
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To perform a selection within a selection, repeat the process.
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For example, open the attribute table then select features using
expression
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Expand the Fields and Values list and double click on adm0cap
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Complete the expression adm0cap to select capital cities only
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Complete the expression “adm0cap”=1 and click on selection
with selection
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You can save the selection as shapefile (right click on layer and
select save Selection As)
7. Lesson 2: Importing files (spreedsheets
& CSV files)
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Open QGIS, select layer on main tab and select Add delimited
text layer.
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In the Create a Layer from a Delimited Text File dialog, click on
Browse and specify location of file. Specify
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Check Custom delimiters, point coordinates and spatial index
finally click OK
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Choose the CRS in the CRS Selector and click OK
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Your data will now be displayed on QGIS canvas
8. Lesson 3: Plugins
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Open QGIS, select plugins on main menu and click on manage
and install plugins
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You activate QGIS pre-installed plugins by checking them.
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To install external plugins, click on get more.
9. Lesson 4: Handling OSM data
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Open QGIS. Select Plugins then OpenLayers plugin and click on
Add OpenStreetMap layer.
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Type of place of interest in Name contains.. and select the first
result
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Select Vector from main menu select open street map and finally
download
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Provide storage location and name then click OK
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The downloaded file is .osm hence in a non-friendly GISer format,
to convert it, select vector choose OpenStreetMap and click on
Import topology from XML
10. Lesson 4: Handling OSM data
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Choose the downloaded .osm file as the Input XML file, name
the output file SpatiaLite DB file as X.osm.db then create a
spatialite db connection and hit OK
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Now create SpatiaLite geometry layers by selecting vectors,
OpenStreetMap, Export topology to SpatialLite
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Browse for the .osm file in the input section, select export type,
name the output layer and check on load when to canvas when
finished.
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Finally save your work
11. Lesson 5 : Vector styling
Part one
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Open QGIS, select layer and click on vector layer to add a layer.
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Browse to file (lifeexpectancy.zip) location and select WGS84:
EPSG4326 as CRS
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Open attribute table to view attribute to be used for styling
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Now right-click on loaded and go to properties
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Select style the categorized from the styles tab.
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Choose LIFEXPCT as the column and select a desirable color ramp
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Click on classify then OK
12. Lesson 5 : Vector styling
Part two
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Open QGIS and load a vector layer of (railways)
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Open the attribute table and select feature by expression (sov_a3)
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Expand Fields and Values and complete the expression “sov_a3”=USA
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Click on select and save the layer for later use (Right click on layer and
select Save selection as)
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Click browse for CRS option to select a distance projection
(North_America_Equidistant_Conic EPSG:102010)
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Finally check the add saved file to map and click on OK
