Relationship slope - flow accumulation

You may have seen this figure a couple of times, illustrating the relationship between the slope and the flow accumulation for the identification of the debris-flow source areas. Well, the one that is on different publications is wrong. There is an issue in the values of the angles. Here is a corrected figure.

The equations and the implementation in Flow-R are correct, it's only the figure that is wrong ! Thanks to David Peres for pointing that out.