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Implications of friction factor adopting in the conventional tsunami run-up analyses including numerical ones are discussed through examinations of applicability of previously reported tsunami run-up theory (Theory I) depending on an incident bore height h1 at shoreline (initial condition), a constant bottom slope i and a constant sediment median particle diameter d50, that (Theory II) depending on h1, i and a constant density ρ of inundation water with sediment, and that (Theory III) depending on h1, i, ρ and a constant friction factor K under a movable bed, comparing the theories with experimental results on the run-up distance of inundation flow with sediment and the theories mutually. It is confirmed that (1) the theory I considered to have the highest universality among the three theories can properly estimate the experimental run-up distance, (2) adoption of constant values of K and ρ evaluated at shoreline cannot properly estimate the run-up process except for a case that experimental values of incident inundation water depth and incident inundation flow velocity at shoreline are explicitly and independently used to evaluate the initial condition h1 in the theory II and (3) adoption of average values of K and ρ in the run-up process is highly recommended in the present state of the art, if we would like to appropriately estimate the run-up process with constant values of K and ρ which are the conventional approach in the tsunami run-up analyses., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The tsunami attenuation effect by coastal vegetation, such as mangroves, called green infrastructure, is widely known through field surveys of disasters and has been studied experimentally and numerically. Previous studies have investigated wave attenuation effects using two-dimensional numerical calculations. However, three-dimensional numerical calculations are necessary to model various wave conditions, including surf zones. Moreover, mangrove prop root shapes are complex and require small grid sizes for detailed reproduction. In addition, the resistance calculation depends on the grid size in the previous method, and applying this method to field calculations incurs high computational costs. Therefore, CADMAS-SURF/3D was employed in this study to reproduce and model mangrove forests as porous structures, and the Dupuit-Forchheimer (DF) law, whose resistance calculation is independent of grid size, was used to establish a low-cost numerical modeling method for mangrove forests. The coefficients and , which depend on the constituent materials of the porous structure, were obtained by sensitivity analysis. When =1000 and =1.0, the wave height attenuation effect is replicated with relatively good accuracy, regardless of the grid size resolution, by a calculation process reproducing the physical experiment. The relationship between the mangrove shore width and the attenuation effect was verified by three-dimensional numerical field calculations to confirm the validity and generality of the model. Upon establishment, this modeling method can evaluate the effects by of coastal vegetation on disaster attenuation in detail on a large scale., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

In this paper a 3D incompressible Smoothed Particle Hydrodynamics (ISPH) erosion model\ud is proposed to simulate the scouring process behind a large vertical cylinder. The erosion\ud model is based on the turbidity water particle concept and the sediment motion is initiated\ud when the fluid bottom shear stress exceeds the critical value. The previous 2D SPH sediment\ud initiation model is expanded by combining the effects of both transverse and longitudinal\ud sloping beds in a practical 3D situation. To validate the developed model, a laboratory flume\ud experiment was carried out to study the clear water scouring around a vertical cylinder under\ud unidirectional current, in which high-speed video cameras were used for the real-time monitoring\ud of sediment movement. The 3D ISPH results are compared with the experimental data with good\ud agreement in terms of the scouring patterns and scales. Besides, the computed flow velocity field\ud suggests that both the horseshoe vortices and lee-wake flows around the cylinder have been\ud accurately simulated.\ud

Today, surgeons almost always create a stoma through a left or right rectus muscle-splitting incision to avoid placement at the midline laparotomy wound of patients. In the past, some surgeons preferred to create a colostomy in the umbilicus, but the practice did not gain general acceptance and the umbilicus had been regarded as a site to avoid for stoma creation. However, this attitude has recently changed in the field of pediatric surgery and adult laparoscopic surgery. The umbilical site has been used for temporary colostomies for neonates or infants with anorectal malformation or Hirschsprung’s disease. Further, umbilical diverting loop ileostomies have been developed to prevent leakage in adult patients undergoing laparoscopic colorectal surgery, whose umbilicus had already been open at the time of the bowel extraction. These reports indicate the umbilical stoma is feasible, safe and cosmetically superior when reversed. Here we review the history of stoma creation and recent utilization of the umbilical stoma and provide a brief discussion on future perspectives.