Tuflow and estry manual Version 3

Note: For an unknown reason, it is necessary to use SMS Version 8 to view contours. SMS Version 7 only shows the vectors.

The default is to just use the end vertices and the middle vertex to create triangular elements between WLLs. Additional points along the WLLs can be created using WLL Additional Points in the .ecf file. If, for example, two additional points are specified, then two extra points are created on each side of the WLL giving a total of 7 points.

The elevations at points along WLLs are presently based on the channel cross-section hydraulic properties table (as reproduced in the .eof file). The elevations are set as constant increments from the bottom elevation of the table to the top elevation. The width at each elevation determines the location of the point along the WLL. The method of locating additional points is controlled by WLL Adjust XS Width. The default method is to adjust the flow width from the hydraulic properties table proportionally along the length of each WLL side. The alternative approach uses the true flow width as would be determined from the hydraulic properties table.

If no additional points are specified, the end points will have an elevation equal to the top elevation in the table and the middle point to the bottom elevation. For fancier looking animations, specify additional points.

If a WLL crosses two or more channels, the channel closest to the middle vertice (3 point line) or half-way point (2 point line) is used.

If a WLL middle vertice snaps to a node with, say two or more channels on the upstream side, the channel it uses to determine flow values is that channel that is closest in angle to the WLL's perpendicular based on the WLL's two end points.

The 1D velocity vectors vary in magnitude across the WLL. At present this is to more easily view the results, with the calculated velocity being the largest one, ie. that shown at the middle vertex along the WLL. Alternative velocity determination based on the relative roughness and depth across the cross-section using Method B below allows more accurate velocity and flood hazard mapping of the 1D results.