A groyne is defined as a non-permeable structure, oriented normal to the baseline.
You can create a new groyne clicking on the ‘New groyne’ button.
You have to define the position and bypass length of the groyne. The position of the groyne is defined by the position of the tip. The bypass length defines the section length at the tip of the groyne where longshore bypass of sediment may occur despite the presence of the structure. The down-wave sheltering effect of groynes is calculated from an empirical formulation.
A groyne may, contrary to Jetties, be positioned behind Offshore breakwaters.
Figure 5.14 Definition of groyne
It is possible to define a negative bypass length to e.g. block all transport from upstream as illustrated in Figure 5.15 below.
Figure 5.15 Using negative bypass length to block transport
