I have an issue for the result of QGIS Zonal statistics mean values. I expect the value for the polygon marked red (poquoson) is about 26.6 but it seems that it is averaged value over one right shifted cells. Values showing in small black font are mean values for the each polygon according to zonal statistics. Values showing in blue are raster values in us.tmax_nohads_ll_20140525_float.tiff enter image description here

Here is "identify results" enter image description here

I made zonal statistics using files with tl_2013_us_county.shp & us.tmax_nohads_ll_20140525_float.tiff on http://www.qgistutorials.com/en/docs/sampling_raster_data.html

1st thing I did was to change CRS for tl_2013_us_county.shp to EPSG4326. I believe that CRS of us.tmax_nohads_ll_20140525_float.tiff and tl_2013_us_county.shp became the same in such a way.

2nd I executed zonal statistics

Platform is QGIS2.18.13 32bit On Windows 10 Pro 64bit Intel Core i5-6500 CPU

Is there any way to get values what I expect?

For above case, expected value is over 26.06 instead of 25.08.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.