Slide 27 of 30
Notes:
The “Actual Gradient” is the average land surface gradient plotted as a function of contributing area for a steady-state landscape simulated by the model of Howard (1994, op. Cit.). The slope gradient is the theoretical gradient that would be required to erode the landscape solely by linear diffusive creep. The two plots of fluvial gradient are end-member cases. Fluvial Gradient 1 is for regolith and bedrock having equal erodibility and the regolith supplied to the channel being uniform along the channel profile. The lower fluvial gradient is that solely for erosion of bedrock. The slope divergence uses the axis on the right and is greater than zero (convex slopes) near divides and less than zero (concave valleys and channels) for large drainage areas.
