QGIS 3.8

More Datasets in QGIS

Author

George Wong

Date, Revisions

17 August 2019

Software

QGIS 3.8

Description

More experimentation in QGIS 3.8. Replicating my workflow from ArcGIS in QGIS using some familiar datasets.



Summary

Really liking the QGIS interface the more I use it. If you can use ArcGIS, you should be able to figure out QGIS like me. There are features in QGIS that I really like, and there are also things that ArcGIS is better at doing. There is no harm in learning both right? There is also a matter of the A$10,000 seat license using ArcGIS commercially. QGIS is free.

As far as tech support goes - we are usually on our own anyway. If you can't fix simple bottlenecks you shouldn't be working in this field. :D

Symbology and labels displayed at different scales

Rules based symbology

Definition query (ArcGIS) --> Query builder (QGIS)

This is located under Layer Properties and then selecting Source > Query Builder. In the new window, you can build your SQL Query the same way as ArcGIS.

Query builder

In this example I have a layer that has all the adjoining local government areas to the Hawkesbury, so I selected all records except the Hawkesbury to create a doughnut. Then I symbolise the adjoining areas in a lighter tone (to indicate outside our jurisdiction or geographic extent).

Doughnut

Heat maps

I really like this feature in the base version of QGIS. You have to purchase a separate license (Spatial Analyst) in ArcGIS to do this. Heat maps are visualisation tools for demonstrating spatial density or cluterring of features. Here I'm looking at crash data from the NSW RMS. The more collision sites close together, the hotter it appears. So logically the sites would heat up around town centres, major intersections and bendy roads.

Heat maps Heat maps Heat maps

It's so easy to setup too. In Spatial Analyst of ArcGIS you have to run some unintuitive tools to do a heat map. In QGIS it was as simply as selecting a dropdown list under Layer Properties > Source. Might have to check the documentation to see what the other settings do but I'm impressed with the output.

Heat maps

Traffic counters

So I've been working with traffic counters for a few months and I wanted to display them in QGIS. Nothing revolutionary, just breaking down into five classes and changing the legend. Looks good enough. Sure beats looking at a spreadsheet.

Traffic counters Traffic counters

Layouts / Printing

I hit a snag with the Layout window trying to generate an A4 PDF. It's not impossible I just need to fine tune the process and not expect it to be perfect after 15 minutes of testing.



back to
WORK