Sections of special geometrical shape can be input in parametric form.

Circle: defined by its radius R, the bottom elevation ZF, and the bank elevation ZB. If ZB is not entered, ZB = ZF + 2R.

Figure 6

Culvert: defined by the bed width L, the side slope m (which may be negative) and by the bed elevation ZF and bank elevation ZB.

Figure 7

Power Relationship: defined by XL0, a, the bank elevation and the bed elevation.

L = XL0 * (Y/Y0)a

with:

Y0 = ZB - ZF
Y = Z - ZF water depth

The parabolic profile corresponds to a = 0.5

Figure 8

Rectangle: defined by its width, bed and bank elevations.

Figure 9

Trapezium or triangle: Defined by its bed width L (nil for the triangle) and the canal bed and bank elevations. Side slope may be negative in the trapezium case. In case of negative slope, if the section gets closed at a level below ZB, the program makes the necessary adjustment to the bank elevation.

Figure 10