[GRASS-user] Curvature in r.slope.aspect

[Aldo Clerici]

GRASSusers,
I have a very simple question regarding the output of r.slope.aspect.
I know that slope and aspect are the first derivatives of elevation and are
expressed in degrees, while profile and tangential curvatures are the second
derivatives of elevation. What I would like to know is the units in which
curvatures are expressed. 
In other words, what does it mean a curvature of 0.05? 

Thanks in advance.

Aldo Clerici
Parma University