A short culvert is defined as a cross (line) section where the total discharge across the cross section is calculated using empirical formulas and distributed along the cross section. In the numerical calculations the cross section is defined as a section of element faces which is treated as an internal discharge boundary (weak formulation). A long culvert is defined by a longitudinal line as shown in Figure 6.8 where inlet and outlet locations are defined as two extent lines at the ends of the transversal line. The polyline (line section) in the numerical calculations for each of the two extent lines is defined as a section of element faces. A long culvert is treated as two connected area sources where the total discharge is calculated using empirical formulas. For each of the two extent lines, the area is determined at the area of the elements to the right of the section of element faces.
Depending on the choice of property page you can see a Geographic View or a List View of the culverts.
There are two different methods for specification of the culverts. In the List View you can create a new culvert clicking on the "New culvert" button. By selecting a culvert in the Culvert list and clicking on the "Delete culvert" button you can remove this culvert. For each culvert you can specify the name of the culvert. The specification of detailed information for each culvert is made subsequently. From the List View page you can go to the dialog for specification by clicking on the "Go to .." button or by selecting a culvert in the Culvert list and clicking on "Edit culvert" button.
In the Geographic View it is also possible to create a new culvert by double-clicking a position on the map or by selecting "New culvert" from the context menu. The name of the culvert and the type of the culvert must then be specified. The culvert type can be either a short culvert or a long culvert (see Culvert type). For a long culvert the width of the start line and the end line also have to be specified. The position on the map will be the first point defining the cross-section for a short culvert and the first point for the longitudinal line for a long culvert. The geographical position of the culvert can then be edited. The additional information for the culvert is made subsequently.