In Zainali et al, (2017) and in Irish et al, (2014) we studied the interaction of long waves with arrays of emergent cylinders inside regularly spaced patches, representing tsunamis interacting with discontinuous patchy coastal vegetation.
Our results in Zainali et al, (2017) show that patches provide protection for the areas behind them. However they might also cause amplification of local water depth in those areas as well. As we can see, the following figure shows the number of times that the water depth gets incremented due to presence of patchy vegetation compared with the case of no patches at all. Note that the tsunami develops from left to right
We also observed that the denser the patch, the higher the risk behind them related to the maximum water depth (more intense red areas). This infers that obstacles located in the tsunami wave trajectory might increase the risk in certain locations, which its understanding is crucial in determining hazards assessments.
Roberto Marivela, Ph.D. 