pente.md

Slope

Definition

The slope used in all Cassiopée's modules is the topographic slope:

The grade (also called slope, incline, gradient, mainfall, pitch or rise) of a physical feature, landform or constructed line refers to the tangent of the angle of that surface to the horizontal. (Source: Wikipedia)

The slope ((I)) in m/m used in Cassiopee's modules is:

$$I = \Delta h / d = \tan(\alpha)$$

Important:

All calculation modules consider a descending slope as positive except for the "Jet Impact" module where a positive slope will be considered as rising and vice versa. To invert the slope in a calculation sequence of linked modules, use the "linear function" module with (a= -1) and (b=0).

The "Slope" module

This tools allows to calculate the missing value of the four quantities:

• upstream elevation ((Z_1)) in m;
• downstream elevation ((Z_2)) in m;
• length ((d)) in m;
• slope ((I)) in m/m, with (I = \frac{(Z_1 - Z_2)}{d}).