<div dir="ltr"><p dir="ltr">Here's a step-by-step tutorial on the Zonal Statistics plugin <br>
<a href="http://www.qgistutorials.com/en/docs/sampling_raster_data.html" target="_blank">http://www.qgistutorials.com/en/docs/sampling_raster_data.html</a></p>
<div class="gmail_quote">You can use a custom field prefix for each of the rasters and you will have columns representing stats for each of the year.</div><div class="gmail_quote"><br></div><div class="gmail_quote">-Ujaval</div><div class="gmail_quote"><br></div><div class="gmail_quote">On 06-Oct-2015 1:13 am, "Michael Treglia" <<a href="mailto:mtreglia@gmail.com" target="_blank">mtreglia@gmail.com</a>> wrote:<br type="attribution"><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><div><div>Hi Sam,<br><br></div>Important point of clarification: Do you want all of the individual pixel values? Or aggregate statistics, like min/max/mean/med...?<br><br></div>For the latter, there are a few tools you can use. I typically use a tool in the Processing Toolbox, implemented in SAGA: Go to Processing Toolbox - > SAGA -> Shape-Grid -> Grid Statistics and you'll be able to get those stats for your desired grids. The only downside, if i recall correctly, is that the column names don't necessarily indicate which layer the stats are from, if you're operating on multiple rasters at a time. There's a 'Zonal Statistics' tool also, which I think works well too. It is a plugin - it is a 'core plugin', which means it come with QGIS,though you might need to activate it (can't remember). If it is already activated, you'll see it when you go to the 'Raster' toolbar menu. If you don't see it there, you can search for it in the 'Plugin' dialogue and make sure the box next to it is checked. <br><br>(more details on plugins here: <a href="https://docs.qgis.org/2.8/en/docs/user_manual/plugins/plugins.html" target="_blank">https://docs.qgis.org/2.8/en/docs/user_manual/plugins/plugins.html</a>)<br><br></div><div>If you want the former, that might be a bit more complicated, and is something I typically do directly in R, but could give advice here too.<br></div><div><br></div>hope that helps!<br></div>mike<br></div><div class="gmail_extra"><br><div class="gmail_quote">On Mon, Oct 5, 2015 at 1:39 PM, Sam Almond <span dir="ltr"><<a href="mailto:sam_almond@hotmail.com" target="_blank">sam_almond@hotmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><div dir="ltr"><p class="MsoNormal">Dear QGIS Users,<u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">I am new to using qGIS and can’t find an obvious solution to
my problem. <u></u><u></u></p>
<p class="MsoNormal"><u></u> <u></u></p>
<p class="MsoNormal">I have created a time series of NDVI rasters covering my area of interest. The NDVI time series is derived from the Landsat imagery spanning a decade of so. I also have a created a vector layer, consisting of polygons,
which represents digitized farmed fields (70 or so). The plan is to use the polygons
to extract the raster values from the time series, ideally one year at a time. The ideal scenario is to be provided with the pixel values per field (polygon) per NDVI over the year. Is this possible? Help appreciated.<u></u><u></u></p><p class="MsoNormal"><br></p><p class="MsoNormal">Many thanks</p><span><font color="#888888"><p class="MsoNormal"><br></p><p class="MsoNormal">Sam </p> </font></span></div></div>
<br>_______________________________________________<br>
Qgis-user mailing list<br>
<a href="mailto:Qgis-user@lists.osgeo.org" target="_blank">Qgis-user@lists.osgeo.org</a><br>
<a href="http://lists.osgeo.org/mailman/listinfo/qgis-user" rel="noreferrer" target="_blank">http://lists.osgeo.org/mailman/listinfo/qgis-user</a><br></blockquote></div><br></div>
<br>_______________________________________________<br>
Qgis-user mailing list<br>
<a href="mailto:Qgis-user@lists.osgeo.org" target="_blank">Qgis-user@lists.osgeo.org</a><br>
<a href="http://lists.osgeo.org/mailman/listinfo/qgis-user" rel="noreferrer" target="_blank">http://lists.osgeo.org/mailman/listinfo/qgis-user</a><br></blockquote></div>
</div>