I am working with this DEM obtained using terraincache, it uses mapzen data. The SRC is WGS 84.
I ran this GDAL command to get the slope:
gdaldem slope -s 111120 dem.tif slope.tif (I had to do scaling because of the SRC)
The resulting image looks fine but it's not smooth, it has weird lines over it, like contour lines.
You can download the DEM file here: https://gofile.io/?c=Du7WnM
Does anyone have an idea of how to solve it?
Thanks in advance for your help,
P.S. I made this question here too: https://gis.stackexchange.com/questions/353983/slope-obtained-with-gdal-has-weird-lines