How to Download and Visualize Google Building Footprint Data Using QGIS

Step 1: Understanding the Building Footprint Dataset

The Google Building Footprint dataset contains approximately 1.8 billion building detections and is currently in version 3. This dataset can be utilized across various sectors such as:

• Population mapping
• Humanitarian response
• Environmental science
• Addressing systems
• Vaccination planning
• Statistical indicators

This dataset includes a confidence score ranging from 0.65 to 1, indicating the accuracy of the building footprint in relation to satellite imagery.

Step 2: Accessing the Data

To access the dataset, you have three options:

• Download it as CSV files
• Access it from Google Earth Engine assets
• Use the data for various applications as per your needs

The current version adds new regions in Latin America and the Caribbean, improving accuracy based on updated satellite imagery.

Step 3: Downloading the Data

To download the data, you can search for your specific location or zoom in on the map using the control key and mouse wheel. After selecting the desired area, click to download the CSV file.

Step 4: Importing Data into QGIS

Once you have downloaded the CSV file, open QGIS (a free and open-source GIS software). Follow these steps:

1. Go to Layer > Add Layer > Add Delimited Text Layer.
2. Select the downloaded CSV file.
3. In the file format section, choose CSV (comma-separated values).
4. Set the X field to longitude and the Y field to latitude.
5. Select Well Known Text for geometry type.
6. Choose WGS84/EPHG 4326 as the coordinate reference system.

Step 5: Analyzing the Data

After importing, click Add to display your data. You can open the attribute table to view latitude, longitude, area, and confidence scores. To filter for high accuracy, you can only select buildings with a confidence score above a certain threshold.

Step 6: Exporting Data

If needed, you can export the data as a GeoJSON file or shapefile. To do this:

1. Right-click on the layer and select Export > Save Features As.
2. Select the desired format (e.g., shapefile).
3. Name your file and keep the default coordinate reference system.
4. Click OK to save.

Step 7: Comparing with Base Maps

To validate your data, you can compare it by adding a base map. Go to Web > QuickMapServices and select a base map option (e.g., OpenStreetMap Standard).

FAQ

What is the Google Building Footprint dataset?

The dataset contains building footprints detected using satellite imagery, which can be applied in various fields like urban planning and environmental studies.

How can I use this dataset in my projects?

By importing the dataset into GIS software like QGIS, you can analyze, visualize, and utilize the data for mapping and planning purposes.