A Beginner’s Guide to Acquiring Shapefile Data For Any Country
Welcome to this brief tutorial on downloading administrative boundary data for any country on Earth. In this guide, we’ll walk you through the steps to access and download this data from the GADM website.
Step 1: Visit GADM
Begin by navigating to the GADM website. This site provides access to administrative boundary data for various countries.
Step 2: Select Your Country
Once on the GADM homepage, click on Data Maps at the top. Then select Country to choose the country you are interested in. For this tutorial, we will select Australia.
Step 3: Choose Your Data Format
After selecting Australia, you will see options to download the data in different formats: GeoPackage, Shapefile, or GeoJSON. It’s important to note that the GeoPackage and Shapefile will be provided as zipped files.
Step 4: Download the Data
Choose the format you prefer. In this case, we will select Shapefile. Once selected, the download will start shortly.
Step 5: Unzip and Open the Data
After the download is complete, unzip the shapefile. Open QGIS and create a new project. To add the layer, select Add Vector Layer and navigate to the unzipped shapefile of Australia.
Step 6: View Administrative Boundaries
Once you’ve added the shapefiles, you will see the different administrative levels (0, 1, and 2). You can select all three levels to visualize the administrative boundaries of Australia.
FAQ
Can I download data for any country?
Yes, GADM provides administrative data for many countries across the world.
What formats are available for download?
From GADM you can download data in GeoPackage, Shapefile, or GeoJSON formats. Other sources such as Natural Earth and DIVA-GIS may also offer KML and additional formats.
What software do I need to open the shapefile?
You can use QGIS, ArcGIS, or any GIS software that supports shapefiles to open the data. GeoPackage and GeoJSON files are also supported by most modern GIS applications.
What about DIVA-GIS?
DIVA-GIS is the source a lot of people still search for when they want free country-level shapefiles, so it is worth being clear about where it stands.
The old download URL is dead. The widely shared address www.diva-gis.org/gdata no longer resolves. DIVA-GIS was rebuilt as a static site and its data now lives at diva-gis.org/data.html, where you can still download administrative boundaries, roads, railroads, elevation, land cover, population and gazetteer data by country, as shapefiles.
But check the age of what you download. DIVA-GIS is now effectively an archive rather than a maintained dataset. Its own data page labels the population density layer “old” (it is a global grid from 2000), and says of the gazetteer: “This is very old now. There are better services for this.” The administrative boundaries are descended from early GADM releases.
What to use instead. For current administrative boundaries, use GADM — the steps at the top of this guide cover exactly that, and GADM is the project DIVA-GIS’s boundary data originally came from. For roads and other infrastructure, OpenStreetMap extracts via Geofabrik are far more current. DIVA-GIS is still useful if you specifically need its older climate or land cover grids, or you are reproducing an older analysis that used it.
Other Sources for Country Shapefile Data
Natural Earth Data: https://www.naturalearthdata.com/
DIVA-GIS: https://diva-gis.org/data.html
OpenStreetMap: https://www.openstreetmap.org/
Humanitarian Data Exchange (HDX): https://data.humdata.org/
Geofabrik: https://download.geofabrik.de/
USGS Earth Explorer: https://earthexplorer.usgs.gov/
Keep in mind that the availability, quality, and format of data may differ across sources, so it is essential to choose the one that best suits your needs. Also be aware of any licensing restrictions, and always give appropriate credit to the data providers.
Important Factors When Working with GIS Shapefile Data
- Data quality and accuracy: The quality of GIS data can vary significantly depending on the source, methodology used for data collection, and processing steps involved. Assess the accuracy of your data, and be aware of any inconsistencies or errors that could impact your analysis.
- Data projections and coordinate systems: GIS data can come in various coordinate systems and projections. Ensure that all your data layers are in the same projection, or transform them into a common one. Using mismatched coordinate systems can lead to incorrect spatial relationships and measurements.
- Data formats: GIS data comes in various formats, such as Shapefiles, GeoJSON, KML, and others. Ensure that your GIS software supports the format you are working with or convert the data into a compatible format using GIS tools or libraries.
- Data licensing and attribution: Always comply with the terms of use, licensing, and attribution requirements of the data provider. Different datasets may have different usage restrictions, so it is crucial to understand and respect these terms.
- Metadata: Metadata provides essential information about the dataset, such as the data source, collection methods, spatial reference, and attribute descriptions. Always review the metadata to understand the context, limitations, and potential caveats associated with the data.
- Data preparation and processing: GIS data often requires preprocessing, such as cleaning, georeferencing, and attribute modifications. Ensure you dedicate adequate time and resources to prepare the data for analysis and visualization.
- Documentation and reproducibility: Document your data processing steps, analysis methods, and any custom scripts or tools used in your project. This documentation helps ensure your work is reproducible and facilitates collaboration with others.
