I'm using QGIS 3.12's Raster -> Analysis -> Hillshade tool on a fairly coarse DEM provided by the British Columbia provincial government.
The DEM has elevation values between 500m and 2650m, so a range of around 2150m. The image below shows the output in my area of interest. On the mountain (left) side the hillshading mostly works as expected. However, on some parts of the mountain, and in the neighbouring valley (right), there is noise and some striping. This occurs in areas where cells differ by 1 or 2 metres, some of which may be real-world variations while others may be anomalies / errors in the data.
The following image is zoomed to an area of striping. From left to right elevation drops by only 5 metres and the slope is consistent, yet the hillshading algorithm generates a lot of noise.
Is there any way I can limit the hillshading output to only 'significant' elevation change? E.g. if elevation across the DEM changes by 2000m then only show changes where elevation changes by at least 20m?
I tried changing the Z factor up and down and switching between ZevenbergenThorne and Horn's formula but neither approach made a significant difference.
