<html><head></head><body>Hi,<br>A starting point can also be the Processing "overlaps analysis" algorithm [0] (sorry I don't know how the output actually looks like) followed by some aggregate analysis.<br><br>[0] <a href="https://docs.qgis.org/testing/en/docs/user_manual/processing_algs/qgis/vectoranalysis.html#overlap-analysis">https://docs.qgis.org/testing/en/docs/user_manual/processing_algs/qgis/vectoranalysis.html#overlap-analysis</a><br><br>Regards,<br>Harrissou<br><br><div class="gmail_quote">Le 11 février 2022 17:58:00 GMT+01:00, chris hermansen <clhermansen@gmail.com> a écrit :<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<div dir="ltr"><div dir="ltr">Michael and list<br></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Fri, Feb 11, 2022 at 8:49 AM Michael Williamson <<a href="mailto:michael@michaelandjane.org.uk">michael@michaelandjane.org.uk</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left:1px solid rgb(204,204,204);padding-left:1ex"><div style="overflow-wrap: break-word;" lang="EN-GB"><div class="gmail-m_-5520252830501938970WordSection1"><p class="MsoNormal">I am sure this is easy but I can’t work out which facility to use<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">I have two layers. Layer A is made up of some large polygons while Layer B is made up of smaller polygons. The Polygons in Layer A overlap one or more of the polygons in layer B. In most cases the overlap is 100% but there are a few cases where the overlap is less than that.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">Layer B contains population and other data as numerical attributes and I want to populate corresponding attributes in layer A with the weighted total of the attributes in layer B depending on the amount of overlap.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal">I have found various tools but I cannot work out which one to use. The ones I have found seem to do part of the job but not all of it.<u></u><u></u></p><p class="MsoNormal"><u></u> <u></u></p><p class="MsoNormal"></p></div></div><br></blockquote><div>Probably you want</div><div><br></div><div>Vector > Geoprocessing Tools > Intersection</div><div><br></div><div>That will give you a new layer C with the geometric intersections of your Layer A and Layer B. The attribute table for Layer C will contain the attributes of both A and B.<br></div></div><br clear="all"></div></blockquote></div></body></html>