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