Distribution

The distribution of the calculated total discharge along the section faces can be specified in two ways

·         Uniform

·         Non-uniform

For a short culvert the discharge is in both cases distributed to the faces for which the element to the left and right of the face are both a wet element and else the discharge is distributed to the faces for which the upstream elements are wet elements. When non-uniform distribution is applied the discharge will be distributed as it would have been in a uniform flow field with the Manning resistance law applied, i.e. relative to h^5/3, where h is the total water depth.

For a long culvert the discharge is in both cases distributed to the faces for which the element to the right of the extent line is a wet element. If no ele­ments are wet the discharge is distributed uniformly to all faces in the section. When non-uniform distribution is applied the same approach as for short cul­verts is used. The non-uniform distribution is, in most cases, a good approxi­mation. This does not apply if there are very large variations over the bathymetry or the geometry.

A uniform distribution is applied for the vertical distribution.

For Composite structures the distribution for the first structure is applied.