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Extensive studies have been carried out to study the performance of mangrove forests in wave height reduction. In this study, the reduction of the inundation and run-up of leading tsunami waves by mangrove forests was investigated through a series of laboratory experiments conducted in a long wave tank. The inundation and run-up were measured using a high speed CCD camera. Solitary waves were used to model the leading tsunami waves. Five vegetation models representing three forest densities and two tree distributions were examined on an impermeable sloping beach, and they were compared with the non-vegetated slope in view of wave reflection, transmission, and run-up. Results show that both incident wave height and run-up could be reduced by up to 50% when the vegetation was present on the slope. Dense vegetation reduced the wave transmission because of the increased wave reflection and energy dissipation into turbulence in vegetation. Normalized wave run-up on the beach decreased with the increase of both normalized incident wave height and forest density. Effect of forest density on the wave run-up on the sloping beach was further examined, and an empirical formula with the density incorporated was proposed. The study also highlighted the importance of tree distribution to wave interaction with vegetation on the slope when the forest density was unaltered, and run-up reduction difference between tandem and staggered arrangements of the trees could reach up to 20%.

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The vulnerability of low-lying reef-fringed atolls to coastal inundation in extreme wave events is of increasing concern in the context of global sea level rise. Wave-induced setup is an important component of wave runup along reef shorelines. We improved a semi-analytical model to investigate wave-induced setup over fringing reefs crested by a shallow reef. Using mass balance and hydraulics, we developed the model based on flow around reef crest kinematics. We proposed a scaling factor to account for flow unsteadiness and reef-crest shape effects. Our solution showed that wave setup on the reef flat is a function of both offshore wave steepness and the wave refection coefficient. Validation of the model by laboratory data shows that the model reproduces the maximum wave-induced setup on the reef flat in the presence of a reef crest with diffident crest widths. Applying the model to experimental data under various reef configurations and wave conditions were also successful. We found that the scaling factor in the model increased with increasing fore-reef slope but was insensitive to variations in reef-crest width. A key requirement for the model to do is that the reef-crest submergence must be small enough or nearly emergent so that an approximate critical flow condition exists.

： Looking into risk coalesce appraisal of assets securitization through ecology theory, on the basic of measuring law which is named BES, set three independent variables as followed, concentration degree in trade, concentration degree in service, concentration degree in productions, for the first time, connecting risk coalesce appraisal in assets securitization with niche breadth and niche overlap, what is more, using rates in real evidence analyze to validate feasibility. Keywords: Assets securitization niche breath niche overlap stability of penalty rate