Emma wrote: Hamish wrote: > maybe you could calculate the plan-area of the littoral strip > in a 5m(?) buffer around each one of the lakes and reservoirs?
(set buffer size in proportion to the input data's raster resolution, although this is still really just an estimation and not really solving the fractal problem completely) Emma: > Yes, this would be ok too, how can I calculate this? If you can find lake edges (or at least lake areas), run r.buffer or v.buffer on them with the appropriate distance. r.buffer is more robust, especially in lat/lon, but much more blocky. As Micha said, picking a local UTM zone to reproject the lake polygons into can help to reduce a lot of pain, as it's natural unit is already the meter. In this case I'd avoid reprojecting the raster data if you can help it. once the buffers are made, see also r.report and v.to.db modules for extracting area-in-meters. both work correctly in lat/lon locations as far as I recall. > Thanks for your help,Emma no worries, good luck Hamish _______________________________________________ Qgis-user mailing list [email protected] http://lists.osgeo.org/mailman/listinfo/qgis-user
