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I am trying to create a slope raster in percent with the DEM tool in QGIS. The GDAL command is the following:
gdaldem slope /Users/Downloads/n41w107/imgn41w107_13.img /Users/Downloads/slope.tif -p -s 1.0 -b 1 -of GTiff
The tool runs fine, but the created file
slope.tif has strange data. The statistics for the band are the following:
STATISTICS_MAXIMUM=29834248 STATISTICS_MEAN=1845376.751065 STATISTICS_MINIMUM=0 STATISTICS_STDDEV=1658350.0283881
So they are obviously way to big for percent. What am I doing wrong?
Update: I calculated the Slope in degrees and got the following statistics:
STATISTICS_MAXIMUM=89.999809265137 STATISTICS_MEAN=89.583139343302 STATISTICS_MINIMUM=0 STATISTICS_STDDEV=5.9592219763749
A mean of 89 degrees seems really high to me. Is that reasonable?