I have a raster in Quantum GIS and I am just exploring it. How can I see average of raster value over certain area, marked by mouse? In other words:

  1. How can I select particular area in QGIS?
  2. How can I compute average of raster value over that area?

2 Answers 2


You should try Zonal Statistics plugin.

enter image description here

  • thank you. What about the question 1, i.e. pure area selection? This must be very simple, but I am new to QGIS.
    – Tomas
    Jul 12, 2013 at 17:57
  • create a polygon Jul 13, 2013 at 17:33
  • There's no simpler way of making a rectangle selection? Even MS Paint can do this :-)
    – Tomas
    Jul 15, 2013 at 9:36
  • It is quite simple. More 'simpler' way will require custom tool. QGIS is open-source. You can create and add any tool you need on your own. So go ahead and create one ))) Jul 15, 2013 at 14:17
  • 2
    Look more carefully. I have it. See updated answer. Jul 21, 2013 at 16:26

The select tool can be seen here. If you click on the drop down you can change the method used to select (rectangle, freehand etc): enter image description here

  • this won't help as the select tool is for vector layers only
    – Curlew
    Jan 3, 2014 at 11:07
  • for the raster sure, but if he were to vectorise the data it would be a handy tool for a 'rectangle selection' i think?
    – Rob Lodge
    Jan 3, 2014 at 11:52
  • Then edit your answer to point out all the steps. But note that the question is over 5months old and the OP probably already found a solution
    – Curlew
    Jan 3, 2014 at 12:26

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