Hillslope slope

[changliao1025]

For each subbasin, there are 3 hillslopes.
Each hillslope includes multiple cells; an average slope can be calculated for these cells.
But can we assume the average slope is the slope of the hillslope?

[changliao1025]

Besides, the CDF-based elevation profile feature from the MOSART can be applied as well.
https://gmd.copernicus.org/articles/10/1233/2017/

[changliao1025]

The percentile function is implemented following numpy: https://numpy.org/doc/stable/reference/generated/numpy.percentile.html

[changliao1025]

Since this new feature is added, the new attribute of the subbasin hillslope should be included in the export function.