This could be potentially a problem described in https://github.com/OSGeo/grass/pull/2534. Could you try to run this with the changes in the PR?
Anna On Tue, Jan 31, 2023 at 4:05 PM Helmut Kudrnovsky <hel...@web.de> wrote: > hi, > > given a a mountain area with a high relief energy based upon an ALS DEM > with a 1x1m resolution > > and system: winGRASS GIS 8.2.1 > > g.region -p > projection: 99 (MGI / Austria Lambert) > zone: 0 > datum: hermannskogel > ellipsoid: bessel > north: 358599.5 > south: 345055.5 > west: 221323.5 > east: 236275.5 > nsres: 1 > ewres: 1 > rows: 13544 > cols: 14952 > cells: 202509888 > > DEM range of data: min = 1197.4 max = 3496.68 > > the horizon rasters are calculated by > > r.horizon elevation=als@data step=30 maxdistance=5000 output=horangle > > r.sun is calculated for 15 June > > r.sun elevation=als@data aspect=als_aspect@data slope=als_slope@data > horizon_basename=horangle horizon_step=30 beam_rad=beam_rad166 day=166 > nprocs=2 npartitions=2 > > see the result screenshot in https://pasteboard.co/YShtdFG8C7jk.png > > o the high peak has northern, eastern and southern oriented steep slopes > o the more red, the higher beam irradiance calculated by the r.sun command > above > o the southern oriented footslopes show a high beam irradiance (as > exptected) > o the southern oriented and very steep slopes around the peak show a > similar low beam irradiance as the northern slopes (not expected) > > I have issues to interpret the results, especially the last pattern: > > o Could be the lower beam irradiance in the very southern oriented slopes > nearby the peak due to the very steep slope? > o Do slopes with a high inclination (though southern oriented) reduce beam > irradiance in the implemented model? > > Kind regards > Helmut > _______________________________________________ > grass-user mailing list > grass-user@lists.osgeo.org > https://lists.osgeo.org/mailman/listinfo/grass-user >
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