What is GeoBase Elevation Data?
GeoBase Elevation Data is a freely available Digital Elevation Model (DEM) provided by Natural Resources Canada. It offers elevation information across Canada, suitable for GIS applications like terrain analysis, hydrology, and 3D visualization. The data is typically available at a resolution of 30m or 90m.
Step 1: Download GeoBase Elevation Data
- Visit the GeoBase Portal
Navigate to the official GeoBase website: https://geogratis.gc.ca - Search for “Elevation (DEM)”
Use the search bar and type “Elevation” or “DEM” to find the relevant datasets. - Choose the Dataset
Select the GeoBase Digital Elevation Data (CDED), available in various scales (1:50,000 and 1:250,000). - Download the Data
- Choose your desired scale and location (using a map tile index or coordinate search).
- Download the files in GeoTIFF or ASCII Grid format (GeoTIFF is recommended for QGIS).
Step 2: Load GeoBase Elevation Data into QGIS
- Open QGIS
Make sure you have QGIS installed. (You can download it from https://qgis.org). - Load Raster Layer
- Go to Layer > Add Layer > Add Raster Layer.
- Browse to the folder where you downloaded the DEM files and select the
.tiffile.
- Visualize the DEM
- The elevation data will appear in grayscale.
- To enhance visualization, right-click on the layer > Properties > Symbology.
- Apply a color ramp (e.g., “Terrain” or “Spectral”) for a better representation.
Step 3: Optional — Perform Elevation Analysis
You can perform various analyses using the DEM in QGIS, such as:
- Generate Hillshade: (Raster > Analysis > Hillshade)
- Calculate Slope and Aspect: (Raster > Terrain Analysis > Slope)
- Extract Contours: (Raster > Extraction > Contour)
Tips for Using GeoBase Elevation Data in QGIS
- Always check the Coordinate Reference System (CRS) of the dataset.
- Clip large DEM files to your Area of Interest using Raster > Extraction > Clip Raster by Extent.
- Combine with vector data like rivers, lakes, and administrative boundaries for advanced mapping.
