“Spatial data identifies the geographic location of features and boundaries. The GIS relies on the geometry to render them. ”
GIS software can read and write different data formats. In most cases these formats have their geometry converted to a usable form and no extra steps are needed whilst adding them. CSV(Comma Separated Value) file is a delimited text file that uses a comma to separate values. CSV file stores tabular data (numbers and text) in plain text. Each line of the file is a data record. Each record consists of one or more fields, separated by commas. In this module, we will explore the contents of CSV files and how to add them to QGIS when they contain geographic information.
Goal: To load spatial data from a CSV into QGIS.
Why were you able to add the airports into QGIS but they do not have the latitude, longitude column?
CSV file is a set of database rows and columns stored in a text file such that the rows are separated by a new line while the columns are separated by a semicolon or a comma. If the values stored in a CSV contains geographic data, the CSV file can be loaded into QGIS as a spatial layer. The geographic information can be in various formats.
|latitude and longitude||Geographic co ordinates|
|wkt_text||Well know text representation of a geometry|
|wkb||Well Known binary representation of a geometry|
If the CSV file contains latitude and longitude QGIS will convert this into point geometry. If you have played around with expressions in QGIS you can look at a function called
make_point. This expression takes latitude and longitude as input and converts it into a point geometry.
Click here to download the sample data for the lesson.