In this paper, a yacht project in Tingjiang Town, Mawei, Fujian, is suggested as an example of a barge type breakwater made out of scrap barges. The physical modelling of a two-dimensional flume wave test was carried out on a barge-type breakwater, focusing on the wave dissipation and anchor chain forces under two different mooring methods, the “crossed tilt” mooring and the “front and rear direct pull” mooring, with no change in the size of the breakwater. The test results show that the effect of wave elimination of the barge-type breakwater gradually decreases with the increase of wave elements under different mooring conditions, but the effect of wave elimination of the barge-type breakwater is significantly better under the “crossed tilt” mooring systems than under the “front and rear direct pull” mooring systems; the maximum tension of the anchor chain under the “inner eight” diagonal mooring method is significantly higher than that under the front and rear straight pulling mooring method. The maximum anchor chain tension under the “crossed tilt” mooring system is significantly greater than that under the fore and aft straight mooring method, while the average anchor chain tension does not change significantly under the two mooring methods.

This work presents a novel one-layer nonhydrostatic formulation and model for nearshore waves. The proposed governing equations define velocities and pressures at arbitrary distances from the still water and only contain spatial derivatives of maximum second order. The formulation can be unified into the existing nonhydrostatic models by defining the variables at the middle depth and neglecting certain additional terms. A Stokes-type Fourier analysis was performed to analyze the formulations' properties and determine the location of variables. The proposed formulation exhibited a clear superiority in describing both the linear and nonlinear properties of the coastal waves. The equations were numerically solved using a hybrid-finite, volume-finite difference scheme. The resulting model accurately described the wave-breaking and runup processes that occurred due to the adoption of a shock-capturing scheme and seabed elevation reconstruction. The suggested novel numerical model was validated against two theoretical benchmark tests and three wave transformation experiments.

No abstract

Urban flooding has become one of the most common natural hazards threatening people’s lives and assets globally due to climate change and rapid urbanization. Hydraulic structures, e.g., sluicegates and pumping stations, can directly influence flooding processes and should be represented in flood modeling and risk assessment. This study aims to present a robust numerical model by incorporating a hydraulic structure simulation module to accurately predict the highly transient flood hydrodynamics interrupted by the operation of hydraulic structures to support object-level risk assessment. Source-term and flux-term coupling approaches are applied and implemented to represent different types of hydraulic structures in the model. For hydraulic structures such as a sluicegate, the flux-term coupling approach may lead to more accurate results, as indicated by the calculated values of NSE and RMSE for different test cases. The model is further applied to predict different design flood scenarios with rainfall inputs created using Intensity-Duration-Frequency relationships, Chicago Design Storm, and surveyed data. The simulation results are combined with established vehicle instability formulas and depth-damage curves to assess the flood impact on individual objects in an urbanized case study area in Zhejiang Province, China.

No abstract