[QGIS Basics] GIS File Extensions, GIS File Importing

Hello,

In this post, we'll explore the commonly used data file extensions (file types) in GIS software and their respective import methods.

When you first encounter GIS, you might find the file extensions unfamiliar, leading to confusion.

QGIS supports various extensions such as GeoPackage, SpatiaLite, Shapefile, Tiff, Tif, NetCDF, CSV, etc. While the preferred extension may vary depending on the environment, the most commonly used ones are typically Shapefile, Tif file, and CSV file.

 

Let's examine Shapefile, Tif file, and CSV file in order.

 

1.Shapefile:

Shapefile is a vector file type developed by Esri, the company behind ArcGIS software. It's widely used for combining spatial and attribute information for editing purposes. When loading Shapefile into software, it's essential to load not just the .shp file but also a minimum of three to a maximum of eight other extensions with the same title that are automatically generated during file creation. Here are the essential files:

• .shp file containing feature geometry
• .dbf file containing attribute information in dBase format
• .shx file for indexing

To practice opening Shapefile, please download the Vietnam national map file from the following site and unzip it: [Link: https://data.humdata.org/dataset/cod-ab-vnm]

 

Once unzipped, you'll notice multiple files with the same name but different extensions.

To open them in QGIS, select all eight files and drag them into the QGIS layer panel or main screen.

 

 

You need to select all eight files and drag them into the QGIS left layer panel or the main screen to open three identical files.

Since they are all the same file, you can right-click on two of them and select "Remove Layer" without any issue.

The Vietnam border map that we downloaded has been opened on top of the Google Map added in the previous post.

 

 

2. Tif file:

.tif is a prominent raster file type. Most files used in GIS are either vector or raster. Unlike Shapefile, Tif file can be easily loaded as it consists of a single file. Simply drag the file into the QGIS screen to open it.

 

To practice, download the 2020 Vietnam population data in Tif file format from the following website and drag it into the QGIS window: [Link: https://hub.worldpop.org/geodata/summary?id=6449]

 

The Viet Nam population map has been added to the screen.

 

 

3. CSV file:

CSV file, a familiar extension, stands for Comma-Separated Values. It's often used to represent data that can be converted from Excel (.xml) files. GIS combines spatial and attribute data, but it can't read Excel-based attribute data directly. Therefore, raw Excel files need to be converted to CSV format.

GIS-compatible CSV files typically include longitude (X) and latitude (Y) coordinates.

 

To import a CSV file, click on the 'Open Data Source Manager' icon (Ctrl+L) in the QGIS screen.

 

 

Select 'Delimited Text' from the left menu, navigate to the CSV file using the '...' button in the File name section, and configure the settings accordingly. 

 

If the CSV file contains X, Y columns or Longitude, Latitude columns, the File Format is automatically set to CSV.
In the Geometry Definition section, Point coordinates are selected, and the X field, Y field are filled.

If the CSV column titles are in your local languages, please manually select "X field -> (longitude), Y field -> (latitude)."

 

Once configured, click 'Add' at the bottom right to import the CSV file.

 

 

On top of the Vietnam border map, population map, and energy power plant location map have been represented with points.

 

Then let me conclude the learning about the most representative QGIS supported file types and the practice of opening Shapefile, Tif file, and CSV file within the software.

 

Thank you.