This tool automates variogram modeling and kriging within QGIS, providing a user-friendly interface for spatial interpolation.
Step 1: Install Required Libraries Ensure gstools and numpy are installed in QGIS's Python environment: pip install gstools numpy
Step 2: Create the Python Script Save the following code as variogram_kriging.py in your QGIS Processing scripts directory (e.g., ~/.local/share/QGIS/QGIS3/profiles/default/processing/scripts/)
Step 3: Using the Tool in QGIS Open QGIS and go to the Processing Toolbox.
Navigate to Scripts > Tools and find the script named "Variogram Modeling & Ordinary Kriging".
Input Parameters:
- Input point layer: Select your point vector layer.
- Field to interpolate: Choose the numeric field for interpolation.
- Input polygon layer: Polygon Boundary (Only interpolates within polygon area)
- Variogram model type: Select the desired model (e.g., spherical).
- Lag distance: Set the distance between bins. (max_dist = lag_distance * n_lags)
- Number of lags: Define how many lag bins to use.
- Extent: Specify the output raster's extent.
- Cell size: Set the resolution of the output raster.
- Output raster: Choose the output file path.
Dependencies: Ensure gstools and numpy are installed in your QGIS Python environment.
CRS Warning: Use a projected CRS (in meters) for accurate distance measurements.
Performance: Large datasets or small cell sizes may increase processing time.
This tool automates variogram modeling and kriging within QGIS, providing a user-friendly interface for spatial interpolation.
- Input Validation:
- Ensure your point layer has ≥4 points with meaningful variation
- Confirm the polygon covers part of the grid
- Performance Tips:
- Start with coarse cell sizes (e.g., 100m) for large areas
- Use spherical/exponential models for better convergence
- Troubleshooting:
- Check QGIS Log for model parameters
- Verify output raster statistics in Properties > Information