Experiment inspired numerical modeling of sediment concentration over sand–silt mixtures

The southwestern part of Bohai Bay in northeastern China is a shallow-water coast with a long fetch for water to pile up to produce large storm surge under strong wind action during the extreme weather condition. In addition, the coastline along the bay has experienced significant environmental impacts from large scale harbor constructions in the past two decades. Consequently, there is a pressing need to better understand the effects of two local large scale sequential harbor constructions on storm surge and coastal vulnerability in the bay area. The extreme cold front weather on 10-13th October 2003 caused a 1.31 billion Yuan damage. A two-way coupled tide-surge-wave Delft3D model is used to investigate the impact of the harbor constructions from 2003 to 2016 on the interaction of tide, storm surge and wave during a storm like that. The wind field by the newly-released global reanalysis wind product ERA5 of European Centre for Medium-Range Weather Forecasts (ECMWF) has been improved by assimilation with field observations at a higher resolution than previous version and is used to drive the tide, surge and wave modelling framework. The model results indicate that the storm surge in the study area is dominated by the wind-induced surge before and after the constructions whereas the maximum contribution from wave-induced surge (wave setup) is increased from 5%-15% to 8%–20% by the harbor constructions between 2003 and 2016. It is found that semi-diurnal modulation of storm surge is generated by nonlinear tide-surge interaction, which is mainly attributed to local tidal acceleration in the offshore zone and bottom stress in the nearshore zone respectively. The harbor constructions affect the coastal storm surge mainly through nonlinear tide-surge-wave interaction. In addition, the quarter-diurnal variation of storm surge induced by the harbor constructions is due to the influences of the harbor constructions on the local quarter-diurnal tidal constituents and their modulation of wave momentum transfer to coastal circulation.

Nonlinear tide-surge-wave interaction at a shallow coast with large scale sequential harbor constructions

Wave-current interactions during extreme weather conditions in southwest of Bohai Bay, China

Responses of tidal modification and nonlinearity to large-scale sequential harbor constructions in the northeastern China

Morphological responses of unsheltered channel-shoal system to a major storm: The combined effects of surges, wind-driven currents and waves

Huanghua Harbor, a semiclosed harbor with three 13.32–23.4 km-long breakwaters forming a coal port and a general port, is located on the silt-muddy coast of the Bohai Sea in China. Frequent gales cause thick sedimentation at the entrance and in the outer waterway. In this study, a two-dimensional depth-averaged horizontal version of the Delft3D software is used to formulate a hydrodynamic suspended sediment transport and bed evolution model. This model is validated by field data, including the tidal level, the tidal current, and the concentration of suspended sediment. The validated model is applied to predict the suspended sediment transport for three different wind scenarios and the short-term morphological evolution from a gale and a wave. The suspended sediment concentrations largely increase from gale-induced currents and waves. The predictions from the gale and its induced wave in 2003 and in 2012 indicate that suspended sediments are driven by the current along the jetties and can be easily...

Dong Du

Papers

Influence of Wind Force on a Silt-Muddy Coast: Huanghua Harbor Coast, China