The implementation of the vortex force formalism equations in 2DH within the XBeach-Surfbeat numerical model, while equivalent to those based on the radiation stress formalism already implemented, provides the advantage that the effects of adiabatic wave transformation and dissipation on long wave generation can be separated. Model results reveal that the dissipation term, due to depth-induced breaking, generates free long waves propagating both shoreward and seaward, consistent with the theory of the varying breakpoint mechanism proposed by Symonds et al. (1982). Further analysis is conducted on a synthetic fringing coral reef, with slopes of 1:1 and 1:25. The results demonstrate that both adiabatic and dissipative terms significantly impact long wave generation. However, the dissipation term is most influential on steep slopes, while the adiabatic terms becomes more dominant on milder slopes, in agreement with previous findings in the literature.