Hi Michael, In line with Harrissou's advice, yesterday I tweeted [1] about an extension to the "Overlap analysis" in QGIS, which works on exactly 2 layers and is called "Overlap analysis by class".
The outputs are both overlap area and percentage per class. Perhaps it could help you. See installation instructions at [2]. Regards, Germán ----------- [1] https://twitter.com/GeoTux2/status/1491684612086636547 [2] https://github.com/gacarrillor/QGIS-Resources/#installation El vie, 11 feb 2022 a las 15:49, Harrissou s. (<del...@gmail.com>) escribió: > Hi, > 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. > > [0] > https://docs.qgis.org/testing/en/docs/user_manual/processing_algs/qgis/vectoranalysis.html#overlap-analysis > > Regards, > Harrissou > > Le 11 février 2022 17:58:00 GMT+01:00, chris hermansen < > clherman...@gmail.com> a écrit : >> >> Michael and list >> >> On Fri, Feb 11, 2022 at 8:49 AM Michael Williamson < >> mich...@michaelandjane.org.uk> wrote: >> >>> I am sure this is easy but I can’t work out which facility to use >>> >>> >>> >>> 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. >>> >>> >>> >>> 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. >>> >>> >>> >>> 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. >>> >>> >>> >>> >>> Probably you want >> >> Vector > Geoprocessing Tools > Intersection >> >> 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. >> >> _______________________________________________ > Qgis-user mailing list > Qgis-user@lists.osgeo.org > List info: https://lists.osgeo.org/mailman/listinfo/qgis-user > Unsubscribe: https://lists.osgeo.org/mailman/listinfo/qgis-user >
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