Quick Start¶

Produce a zonal-statistics CSV in four steps.

1. Open the tool¶

From Raster → Multiband Zonal Stats, the toolbar, or the Processing Toolbox.

2. Choose your layers¶

Multiband raster — a file-based (GDAL) raster.
Polygon zones — a polygon or multipolygon layer.
Optionally set an ID field and Name field to label each zone in the output.

Coordinate systems

The raster's CRS is the analysis CRS, and the raster is never resampled. Zones are transformed into the raster CRS automatically. If a layer's CRS is missing or wrong, set a Raster CRS or Zones CRS override — this assigns a CRS, it does not reproject the data.

3. Pick the mode and statistics¶

Choose the tab that matches your raster:

Continuous rasterCategorical raster

Measured values (elevation, temperature, NDVI). Select from count, nodata, min, max, sum, mean, standard deviation, and a Long or Wide layout.

Discrete class codes (land cover, soil type). Select from majority, minority, variety, and a Summary, Class breakdown, or Class counts layout.

Set the Raster bands (all, 1-8, or 1,3,7), and optionally an Exclude values list (e.g. 0) to drop pixels from the calculation.

Preview first

Click Histogram… to see the distribution of a band before you run — a quick way to spot values worth excluding (for example a spike at 0).

4. Save and run¶

Pick an output CSV, optionally set the decimal places, then click Run analysis. The job runs in the background with progress and a safe Cancel, and the CSV is written atomically — a cancelled or failed run leaves no partial file.

When it finishes, click Open result to view the CSV.

What you get¶

Every output row begins with a unique fid. For example, continuous Long output:

fid,polygon_id,polygon_name,band_index,band_name,count,mean,stddev
1,101,North field,1,ndvi,4210,0.62,0.11
2,101,North field,2,ndvi_may,4210,0.58,0.09

See Output & Options for every layout, and Continuous & Categorical for choosing a mode.